Environmental Technology
Systems Awareness
Learning Tool
Enter
Environmental Technology Systems Awareness
Welcome
Welcome to the ‘Environmental Technology Systems Awareness’ learning tool which is one
of four learning tools that have been developed by the Skills for Climate Change project.
How to use this tool
The main way to navigate around this tool, use the forward
bottom right corner of each screen.
and back
arrows in the
In some areas of the tool a set of icons similar to those below will appear for you to select from.
You can click on the
icon from anywhere in the tool to access the module menu page.
Introduction
Welcome to the ‘Environmental Technology Systems Awareness’ learning tool.
The purpose of the tool is to enable you to develop a fundamental knowledge of microrenewable energy and water conversation technologies .
The aim of the learning tool is to :
•
•
•
•
develop your understanding of the fundamental working principles of micro-renewable
energy and water conservation technologies
enable you to recognise the top level regulatory requirements that apply in relation to microrenewable energy and water conservation technologies installation
enable you to recognise the fundamental requirements of building location/building features
for the potential to install micro-renewable energy and water conservation systems to exist.
enable you recognise the typical advantages and disadvantages of micro-renewable energy
and water conservation systems
Please note: This learning tool is not intended to develop the occupation competence to design or
install micro-renewable energy and water conversation technologies. The information and
illustration provided is limited to awareness only. The diagrams provided only contain the relevant
technical detail for awareness purposes and must not be used as installation diagrams.
When is it appropriate to install environmental technology systems?
Before we move onto the rest of the tool, it is important to understand the role that environmental
technology systems have in helping to address climate change and improve sustainability. Before
considering the installation of environmental technology systems it is essential that approaches to
reduce demand and to improve efficiency are taken first .
3
2
1
Learning Tool Overview
This learning tool includes four modules:
To enable you to gain a good overall awareness and understanding, It is recommended that you
study all four modules; however, the modules can be studied in any order.
Each module includes
each learning check before you move on.
To begin, click on any module above.
points. It is recommended that you complete
Module 1: Heat Producing Technologies
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems
Objectives
At the end of this section you will:
•
•
•
•
understand the fundamental working principles of solar thermal hot water systems
recognise the top level regulatory requirements that apply in relation to solar
thermal hot water systems installation work
recognise the fundamental requirements of building location and building features
for the potential to install to a solar thermal hot water system to exist
recognise the typical advantages and disadvantages of solar thermal hot water
systems

Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – Basic System Categories
Although there are a number of
system types, variations and
configurations, solar thermal
hot water systems fall into two
basic system categories:
•
•
passive systems
active Systems
In passive systems, the system circulation takes place by the natural thermosiphon or
convection process. For this process to work the solar collector needs to be mounted below
the storage cylinder. As this arrangement is not as practical in the UK as it is in warmer
countries, the majority of systems installed in the UK are ‘active’ systems where the system
circulation takes place due to the inclusion of a circulating pump.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems - Indirect Active System (with Twin-Coil Cylinder)
Click on each number
for a brief overview of
the purpose of the
system component
1
2
5
3
4
Please note that due to the
intended purpose of this learning
tool, some system components are
not shown. This is not an
installation diagram.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – Direct Active Systems
In direct solar hot water systems, the
domestic hot water that is stored in the
cylinder is directly circulated through the
solar collector.
This type of system can be added to
existing hot water systems, but it is
essential that all system components are
compatible with the system design. For
example, as the domestic hot water is
circulated through the solar collector it is
not possible to add anti-freeze protection
to the system water – therefore some
components such as the solar collector
need to be freeze tolerant.
Please note that due to the intended purpose of
this learning tool, some system components are
not shown. This is not an installation diagram.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water System Components - Solar Collector
Sometimes referred to as a solar panel, the collector is mounted in a suitable
location (usually on a roof). The collector absorbs the sun's energy and uses it to
heat the heat transfer fluid within the system.
Types of Solar Collector
‘Flat Plate’
Solar Collectors
‘Evacuated Tube’
Solar Collectors
Module 1: Heat Producing Technologies
Solar Thermal Hot Water System Components - Differential Temperature Controller
The Differential Temperature Controller (DTC) is the
heart and brains of the system. Linked to high level and
low level temperature sensors the DTC only allows the
system circulating pump to operate when there is:
1. solar energy available
2. there is a demand for water to be heated
Module 1: Heat Producing Technologies
Solar Thermal Hot Water System Components - Circulating Pump
The circulating pump circulates the system heat
transfer fluid which is either water or glycol depending
upon the type of system, around the solar hot water
circuit.
The operation of the circulating pump is controlled by
the Differential Temperature Controller
Module 1: Heat Producing Technologies
Solar Thermal Hot Water System Components – Auxillary Heat Source
In the UK, solar thermal hot water systems require an
auxillary heat source to heat the stored domestic hot
water when there is either:
1. insufficient solar energy to heat the water fully; or
2. no solar energy to heat the water
Where a space heating system is installed, the boiler typically provides the auxillary heat source
for the solar hot water system. Where there is no space heating the auxillary heat source is
typically an electric immersion heater
Module 1: Heat Producing Technologies
Solar Thermal Hot Water System Components – Storage Cylinder
The storage cylinder stores the domestic hot water and allows for the
heat transfer from the solar collector circuit to the stored domestic hot
water. A popular cylinder type is the twin coil cylinder. This type of
cylinder incorporates a lower solar heating coil and a higher auxillary
heating coil. Some cylinders will also include a shunt pump to circulate
the stored water in the cylinder when just the auxillary heat coil is in
operation
One of a number of alternative arrangements is to use a separate solar
pre-heat cylinder as shown below. This arrangement is less common.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems
Question
Answer
Most solar hot water systems in the UK fall into
which system type category?
Active or pumped
systems
Click
here to reveal
What types of solar collector are available?
Flat plate and evacuated
Click here tube
to reveal
What is the function of the Differential
Temperature Controller?
To control the system circulating pump to
Clickthere
here is:
to reveal
operate only when
1. solar energy available
2. there is a demand for water to be heated
What is the purpose of an auxillary heat
source?
To provide back-up
there is no or
Clickheat
herewhen
to reveal
insufficient solar energy available to heat the
water
How did you do?
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – Regulatory Requirements
The installation of a solar thermal hot water system will require
compliance with a number of regulatory requirements including
health and safety, water regulations, electrical regulations. A
competent installation contractor will have a detailed knowledge
of these regulations and will ensure compliance.
Within this section we consider two primary regulatory
requirements in relation to solar hot water systems:
•
•
Building Regulations
Town and Country Planning Regulations
Note: The requirements stated in this section relate to England and
Wales only. The requirements for Scotland and Northern Ireland
may differ.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – Regulatory Requirements
The Building Regulations (England and Wales) comprise of 14 parts.
Seven of these parts may have relevance to solar hot water systems installation.
Part
Topic
Relevance or possible relevance
A
Structure
Where solar collectors
components put load
Clickand
hereother
to reveal
on the structure, in particular wind uplift loads.
B
Fire Safety
Where holes for pipes
may
Clicketc.
here
to reduce
reveal the fire resistant
integrity of the building structure
C
Site preparation and resistance to moisture
Where holes for pipes
may
Clicketc.
here
to reduce
reveal the moisture
resistant integrity of the building structure
E
Resistance to the passage of sound
Where holes for pipes
may
Clicketc.
here
to reduce
reveal sound proof
integrity of the building structure
G
Sanitation, hot water safety and water
efficiency
Hot water safety and
water
Click
hereefficiency
to reveal
L
Conservation of fuel and power
Energy efficiency ofClick
the here
system
the building
toand
reveal
P
Electrical safety in dwellings
Safe installation ofClick
electrical
and components
herecontrols
to reveal
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – Regulatory Requirements
Town and Country Planning Regulations – Building Mounted Collectors
The installation of a solar hot water system collector array is typically classed as permitted
development for houses and bungalows providing :
•
•
•
•
•
the solar collectors are not installed above the ridgeline and do not project more than
200mm from the roof or wall surface.
the solar collectors are sited, so far as is practicable, to minimise the effect on the
appearance of the building
the solar collectors are sited, so far as is practicable, to minimise the effect on the
amenity of the area.
the property is not a listed building*
the property is not in a conservation area or in a World Heritage Site
The Local Planning Authority should be consulted for clarification, particularly for
installations to flats and non-dwelling building types.
*Listed Building Consent may be required even if planning permission is not
required.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – Regulatory Requirements
Town and Country Planning Regulations – Stand-alone Collector Arrays
The installation of a stand-alone solar hot water system collector arrays is typically classed as
permitted development providing :
•
•
•
•
•
•
The array is no higher than four metres
The array is sited at least 5m from boundaries
The size of array is limited to 9m2 or 3m wide and 3m deep
The array is not being installed within boundary of a listed building
In the case of land in a conservation area or in a World Heritage Site the array will not be
visible from the highway.
Only one stand-alone solar installation is being installed.
*Listed Building Consent may be required even if planning permission is not
required.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems - Building location and feature requirements
For the potential to install to a solar thermal hot water system to
exist, as a minimum some or all of the following building and
location factors will need to be considered:
•
•
•
•
•
orientation of the solar collectors
tilt of the solar collectors
adjacent structures or obstructions that introduce overshading
the availability of a suitable solar collector mounting structure
compatibility with any existing hot water system
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – building location and feature requirements
Collector Orientation
In the UK, we tend to relate a south
facing garden in our homes to the
availability of the most sunshine
throughout the day. Well the same
applies in relation to solar hot water
systems.
The ideal orientation is south facing.
Orientations between south east and
south west will also provide good
results.
For buildings with suitable east and west facing roof
areas, a split collector system is possible with solar
collectors mounted on both east and west facing roof
slopes.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – building location and feature requirements
Solar Collector Tilt
As well as orientation, the ‘tilt’ of the solar
collector is also key factor that determines the
amount of solar energy that is transferred from
the sun to the solar hot water system.
Collector ‘tilt’ is the angle that the solar
collector is mounted from the horizontal plane.
Where a pitched roof already exists, the tilt is
typically determined by the roof pitch.
Where there is no pitched roof available, it is possible to mount solar collectors on vertical
and horizontal surfaces. Solar collectors may also be mounted on purpose built support
frames to provide the required tilt. However, this type of installation typically requires
more design consideration and consultation with product manufacturers etc.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – building location and feature requirements
We have identified that the building orientation and collector tilt are key factors in
determining the amount of available solar energy that is transferred from the sun to
the solar hot water system. Now let’s examine some data….
Tilt of
Collector
Orientation of collector
South
SE/SW
Horizontal
E/W
NE/NW
North
961
300
1073
1027
913
785
730
450
1054
997
854
686
640
600
989
927
776
597
500
Vertical
746
705
582
440
371
Annual solar radiation kWh/m2 (Source: Table H2, SAP, 2009)
What is the optimum orientation and tilt given in the table above?
Click on the forward arrow to check your answer
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – building location and feature requirements
Tilt of
Collector
Orientation of collector
South
SE/SW
Horizontal
E/W
NE/NW
North
961
300
1073
1027
913
785
730
450
1054
997
854
686
640
600
989
927
776
597
500
Vertical
746
705
582
440
371
Annual solar radiation kWh/m2 (Source: Table H2, SAP, 2009)
The optimum orientation and tilt given in the table above is south facing at a 30o tilt.
Typically, a collector tilt of between 30o and 40o from horizontal is considered to be very
close to optimum with 35o being optimum.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – building location and feature requirements
Overshading
Any overshading of the solar collector(s) will
have an impact on how much available solar
energy that is transferred from the sun to the
solar hot water system
Overshading
% of sky
blocked by
obstacles
Impact of
overshading
(% reduction in
potential system
performance)
˃ 80%
50%
Significant
˃ 60 - 80%
35%
Modest
20% - 60%
20%
˂ 20%
none
Heavy
None or very
little
Based upon Table H4, SAP, 2009
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – building location and feature requirements
Suitable Collector Mounting Structure
The collector mounting structure must be suitable in terms of
being:
•
of sufficient size (m2)
− typically a minimum of 3- 4m2 of suitable collector mounting
area is needed with approximately 0.75m2 to 1m2 of
collector area being required per person
•
strong enough to support the collectors
− as well as considering the the potential for collapse or
damage to the structure under normal conditions, wind
uplift loads must be considered and assessed.
•
in good condition
− there is no sense in installing a solar collector to a roof that
is in a poor state of repair. Any repairs or refurbishment
should be carried out prior to installing the solar collector(s)
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – building location and feature requirements
Compatibility with any Existing Hot Water System
Existing hot water systems come in various types and configurations. Three types of
systems are shown below:
Point of use systems and instantaneous centralised systems are not normally suitable for use
with solar hot water systems. However, some combination boilers are compatible with solar
pre-heated water. Product manufacturer’s instructions should always be consulted for advice.
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems
Question
Answer
What type of solar hot water system is typically
suitable for a property with and East/West roof
orientation?
A split collectorClick
system
solar collectors
herewith
to reveal
mounted on both east and west facing roof
slopes
What effect will heavy overshading of solar
collectors have on system performance?
A potential reduction
in system
performance of
Click here
to reveal
approximately 50%
What are the essential requirements for a
structure to be suitable for the mounting solar
collectors?
1.
2.
3.
Which type of hot water system is most
compatible with a solar hot water system?
A centalised storage
system
Click here
to reveal
How did you do?
Sufficient size
Click here to reveal
Strong enough
In good condition
Module 1: Heat Producing Technologies
Solar Thermal Hot Water Systems – Advantages and Disadvantages
Some example advantages and disadvantages are:
Advantages
Disadvantages
Reduces carbon dioxide emissions
Not compatible will all existing hot water
systems
Less solar energy is available in the
winter months
Initial installation costs can be off-putting
Solar energy is free, energy costs will be
reduced
Relatively low maintenance is needed
Improves Energy Performance Certificate Needs a linked auxillary heat source
ratings
Well Done! You have now completed the solar hot water systems section.
Click on the forward arrow to return to heat producing technology system menu page
Module 1: Heat Producing Technologies
Heat Pump Systems
Objectives
At the end of this section you will:
•
•
•
•
•
•
understand the fundamental working principles of a heat pump unit
know the common types of heat pump unit
know the types of heat emitters that are suitable for heat pump system installations
recognise the top level regulatory requirements that apply in relation to heat pump
systems installation work
recognise the fundamental requirements of building location and building features
for the potential to install heat pump systems to exist
recognise the typical advantages and disadvantages of heat pump systems

Module 1: Heat Producing Technologies
Heat Pump Systems
What is a heat pump?
A heat pump is a device for converting
low temperature heat a to higher
temperature heat
Some heat pumps can also work in
reverse and convert high temperature
heat to a lower temperature
So how does a heat pump work? ………………
Module 1: Heat Producing Technologies
Heat Pump Systems
How does a heat pump work?
Most heat pumps make use of the mechanical vapour compression cycle commonly known as
the refrigeration cycle to convert heat form one temperature to another. The heat pump
refrigeration cycle works on a similar principle to a domestic refrigerator but in reverse.
Let’s look at how the heat pump refrigeration cycle works ………………
Module 1: Heat Producing Technologies
Heat Pump Systems
Heat pump refrigeration cycle
1. The low temperature heat (heat
source) enters the Evaporator which is a
heat exchanger . A refrigerant on the other
side of the evaporator is at a cooler
temperature than the heat source and heat
is transferred from the source into the
refrigerant causing the refrigerant to
evaporate.
2. The now gaseous refrigerant enters the compressor, resulting in a rise in the temperature and
pressure of the refrigerant.
3. The refrigerant continues its course through the Condenser (which is also a heat exchanger)
transferring the higher temperature heat to either an air or water distribution circuit (often referred to
as the ‘heat sink’ or emitter circuit).
4. The refrigerant, now at a cooler temperature, enters the expansion valve, which reduces its pressure
and temperature to its initial state at the evaporator. The cycle then repeats itself.
Module 1: Heat Producing Technologies
Heat Pump Systems
How efficient are heat pumps?
Heat pumps are classified as a ‘low’ carbon
technology because they need some electrical
energy to operate.
Depending on the application, operating
conditions and type of heat pump utilised,
heat pump energy output can be 300% to
500% more than the electrical energy input.
Heat Pump efficiency is referred to as
Coefficient of Performance (COP)
In its simplest form COP relates to heating output divided by the electrical power input.
For this example the COP is 4.0, calculated as follows:
Heating output (4kW) ÷ Electrical power input (1kW) = 4.0
Module 1: Heat Producing Technologies
Heat Pump Systems
Heat pump technology can convert low temperature heat from an air, ground or water
source to higher temperature heat for use in ducted air or piped water ‘heat sink’ systems.
The type of heat pump unit must be selected in relation to the intended ‘heat source’ and
‘heat sink’ arrangement’
Let’s now look at the options in more detail………….
Module 1: Heat Producing Technologies
External Air Source Heat Pump System Options
A variety of heat pump system arrangements are possible using the external air as the heat
source. Air source heat pump will typically operate at temperatures up to -20 oC. Air source heat
pumps can be single internal units that receive the incoming air through an inlet duct that passes
through the external wall of the building . An popular alternative is the use of an external fan coil
(evaporator) unit that is linked to an internal unit. Fan coil units can be noisy and this need to be
considered at the design stage.
Let’s now look at the ground source options ………….
Module 1: Heat Producing Technologies
Ground Source Heat Pump System Options
A variety of heat pump system arrangements are possible using geothermal ground heat as the heat
source. A variety of closed (sealed circuit) collector loop arrangements can be used.
SlinkyTM type collectors (illustrated) are sometimes used where available ground area (m2) is limited.
External ground source heat pump units (not illustrated) are also available.
Let’s now look at some more ground source options ………….
Module 1: Heat Producing Technologies
Ground Source Heat Pump System Options
An alternative to horizontal ground collector loops is a
vertical collector loop installed in a borehole.
This type of installation requires a specialist drilling rig
to be used to create the borehole. A specialist
contractor is normally used to undertake the drilling
operation.
Vertical borehole collector loops are often used where
the geothermal conditions support the use of a
ground source heat pump but where the available
ground area (m2) is limited.
Click on next for more ground source options ………….
Module 1: Heat Producing Technologies
Ground Source Heat Pump System Options
An ‘open’ vertical borehole ground collector loop is an
alternative to a ‘closed’ vertical borehole ground
collector loop.
With this arrangement , two boreholes are used and
the collector circuit is open and the collector circuit
fluid flows naturally from the open ended return pipe
to the open ended flow pipe. . This type of
arrangement requires the availability of a suitable
geothermal water source.
Click of next for water source collector circuit
options ………….
Module 1: Heat Producing Technologies
Water Source Heat Pump System Options
Where a suitable water source exists such as a lake or a pond, this can be a very effective
alternative to a ground source collector circuit. For illustration purposes the SlinkyTM type collector
is shown in a vertical position, but water source collectors are simply laid on the bottom of the lake
or a pond and weighted as necessary to keep them in place. ‘Open’ water source collector circuits
(not illustrated) are also an option.
Module 1: Heat Producing Technologies
Heat Pump Systems
Question
Answer
What type of heat conversion process does a heat
pump use?
A refrigerationClick
circuit
here to reveal
What types of heat source options exist?
Air, ground and
water
Click
here to reveal
What types of heat sink circuit exist?
Air and piped Click
waterhere to reveal
What is the typical % increase in energy output
from a heat pump in relation to the electrical energy
input?
300% to 500%Click here to reveal
What does Coefficient of Performance relate to?
Heat pump efficiency
(heating
output divided
Click here
to reveal
by the electrical power input)
How did you do?
Let’s now look at the ‘heat sink’ emitter circuit options ………….
Module 1: Heat Producing Technologies
Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuits
One of the factors that affects heat pump system efficiency is the
temperature difference between the heat source and the heat sink.
The closer the temperature between the heat source and the heat
sink circuit, the better the Coefficient of Performance.
Traditional ‘wet’ heating systems that incorporate a condensing boiler
use a mean (average) water temperature of approximately 70oC. A
heat pump system mean water temperature will typically be between
30oC and 40oC
The lower mean water temperature dictates that some types of heat
emitter and hot water storage cylinder are more suitable than others
for use with heat pump systems.
Module 1: Heat Producing Technologies
Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuit Options
4
1
3
2
Heat pumps using a piped Water ‘Heat Sink’ Circuit can be used to heat domestic hot water storage
vessels (1), underfloor heating circuits (2), radiators (3) and fan convector heaters (4). However,
some of these are more suitable than others.
Click on each number for more information and when finished click on next
Module 1: Heat Producing Technologies
Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuit Options
Domestic Hot Water Storage
Heat pumps can be used to heat a domestic hot water storage cylinder.
Standard type indirect hot water storage cylinders are not suitable for
heat pump system due to the size of the heat transfer coil. A ‘tank-intank’ hot water cylinder is the most appropriate for use with heat pumps.
Some heat pump units have an integrated ‘tank-in-tank’ cylinder.
The ‘tank-in-tank’ design provides a large surface to surface contact
between the heating circuit water and the stored domestic hot water.
This design is very suitable due to the lower temperature of the heating
circuit water in a heat pump system when compared to a traditional
boiler-fed heating system.
A ‘boost’ or auxillary heater is required to boost the stored water
temperature to standard 60oC domestic hot water storage temperature
‘Tank-in-Tank’ Hot
Water Cylinder
Module 1: Heat Producing Technologies
Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuit Options
Underfloor Heating
Underfloor heating systems operate at a lower
mean (average) water temperature than a
heating system with radiators.
Therefore, underfloor heating is very suitable for
use with heat pumps.
Module 1: Heat Producing Technologies
Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuit Options
Panel Radiators
Standard type panel radiators are designed to work at a
mean (average) water temperature of approximately 70oC.
A heat pump system mean water temperature will typically
be between 30oC and 40oC
To be effectively and efficiently used with a heat pump system, standard type panel radiators
would need to be significantly over-sized to enable the required heat output to be achieved using
a lower mean water temperature . This factor means that heat pump units are typically less
suitable for use with existing standard type panel radiator circuits that have been sized for a mean
water temperature of 70oC.
Low temperature, high efficiency panel radiators are available and these are more suitable for
use in a heat pump heat sink circuit. Where low temperature, high efficiency panel radiators are
used, the Coefficient of Performance will typically be lower than if underfloor heating is used.
Module 1: Heat Producing Technologies
Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuit Options
Convector Heaters
Natural and fanned convector heaters are suitable for use
with heat pumps.
As is the case with low temperature, high efficiency panel
radiators, where natural and/or fanned convector heaters
used, the Coefficient of Performance will typically be lower
than if underfloor heating is used.
Fanned Convector
Heater
Module 1: Heat Producing Technologies
Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuits
Buffer Tanks
Some heat sink circuits make use of a
component called a buffer tank. In basic
terms, a buffer tank is a vessel that
accumulates and stores heating circuit water
ready for use when needed.
Heat pumps are not designed or sized to meet short-term heat loads. For efficient operation a
heat pump heeds to be able to start-up and run for a period of time. Stop-start operation can
also shorten the life of the heat pump compressor.
Buffer tanks are also useful where an auxillary heat source such as a boiler is being used with a
heat pump. This type of system is known as a bivalent system.
Most air source heat pumps, particularly those with an external fan coil unit need to defrost
regularly. Buffer tanks are also useful to provide heat for the defrost cycle.
Module 1: Heat Producing Technologies
Heat Pump Systems – Regulatory Requirements
The installation of heat pump systems will require compliance with
a number of regulatory requirements including health and safety,
water regulations, electrical regulations. A competent installation
contractor will have a detailed knowledge of these regulations and
will ensure compliance.
Within this section we consider two primary regulatory
requirements in relation to heat pump systems:
•
•
Building Regulations
Town and Country Planning Regulations
Note: The requirements stated in this section relate to England and
Wales only. The requirements for Scotland and Northern Ireland
may differ.
Module 1: Heat Producing Technologies
Heat Pump Systems – Regulatory Requirements
The Building Regulations (England and Wales) comprise of 14 parts.
Seven of these parts may have relevance to heat pump systems installation.
Part
Topic
Relevance or possible relevance
A
Structure
Where heat pumpsClick
and here
otherto
components
put load on
reveal
the structure
B
Fire Safety
Where holes for pipes
may
Clicketc.
here
to reduce
reveal the fire resistant
integrity of the building structure
C
Site preparation and resistance to moisture
Where holes for pipes
may
Clicketc.
here
to reduce
reveal the moisture
resistant integrity of the building structure
E
Resistance to the passage of sound
Where holes for pipes
may
Clicketc.
here
to reduce
reveal sound proof
integrity of the building structure
G
Sanitation, hot water safety and water
efficiency
Hot water safety and
water
Click
hereefficiency
to reveal
L
Conservation of fuel and power
Energy efficiency of
the here
system
the building
Click
to and
reveal
P
Electrical safety in dwellings
Safe installation ofClick
electrical
herecontrols
to revealand components
Module 1: Heat Producing Technologies
Heat Pump Systems – Regulatory Requirements
Town and Country Planning Regulations
Installing a ground source or water source heat pump system does not usually need planning
permission and should fall within permitted development rights.
Due to potential noise issues, most air source heat pump installation currently require
planning permission. However, this is currently being reviewed and as soon as relevant
standards and safeguards to deal with noise have been established air source heat pumps are
likely to be classified as permitted development.
The Local Planning Authority should be consulted for clarification, particularly for
installations in conservation areas and installations to non-dwelling building types.
*Listed Building Consent may be required even if planning permission is not
required.
Module 1: Heat Producing Technologies
Heat Pump Systems - Building location and feature requirements
For the potential to install to a heat pump system to exist, as a minimum
some or all of the following building and location factors will need to be
considered:
•
an appropriate heat source (air, ground or water)
•
the availability of a suitable location to mount the components particularly the potential for noise issues if an air source heat pump is
being considered
•
The compatibility of the proposed installation with any existing
heating and hot water system unless a new heating and hot water
system is to be installed
Module 1: Heat Producing Technologies
Heat Pump Systems
Question
Answer
What is the mean water temperature used in a
heating system connected to a heat pump ?
30oC to 40oC Click here to reveal
What type of domestic hot water cylinder is most
suitable for use in a heat pump system?
A ‘tank-in-tankClick
cylinder
here to reveal
What component can be used to prevent the heat
pump cycling on and off during short-term heat
demand periods?
A buffer tank Click here to reveal
Which type of heat pump installation is most likely
to require planning permission?
Air source
How did you do?
Click here to reveal
Module 1: Heat Producing Technologies
Heat Pump Systems – Advantages and Disadvantages
Some example advantages and disadvantages are:
Advantages
Disadvantages
Reduces carbon dioxide emissions
Not usually suitable for connection to existing
heating systems using panel radiators
Efficiencies between 300% to 500% are typical.
Initial installation costs can be off-putting
Relatively low maintenance is needed
Air source installations can present a noise
issue
Improves Energy Performance Certificate
ratings
Ground source installations require a large
ground area or a borehole
Well Done! You have now completed the heat pump systems section.
Click on the forward arrow to return to heat producing technology system menu page
Module 1: Heat Producing Technologies
Biomass Fuelled Systems
Objectives
At the end of this section you will:
•
•
•
•
understand the fundamental working principles of biomass fuelled systems
recognise the top level regulatory requirements that apply in relation to biomass
fuelled systems installation work
recognise the fundamental requirements of building location and building features
for the potential to install to a biomass fuelled system to exist
recognise the typical advantages and disadvantages of biomass fuelled systems

Module 1: Heat Producing Technologies
Biomass Fuelled Systems
The Biomass Resource
Biomass fuelled systems are generally
considered to be carbon neutral. This is
because the carbon dioxide released when
combustion takes place is equal to the
carbon dioxide that was used during tree
growing process.
Even when the carbon dioxide produced
through the growing, harvesting and
transportation processes is taken into
account, biomass fuelled systems are
extremely carbon friendly when compared
to fossil fuelled appliances

Module 1: Heat Producing Technologies
Biomass Fuelled Systems
Within this section we look woody biomass fuels i.e fuels that come from a wood source
Woody Biomass fuels come in three main types:
Logs
Logs have been used to provide heating for hundreds of
years and is the original biomass fuel. Logs for biomass
appliances need to be of maximum length and diameter
Wood Chip
Wood Chip is typically produced from the ‘small roundwood’ that is left over when trees are felled and logs are
harvested but can also be produced from reclaimed timber
Pellets
Wood pellets are pellets made from fine wood particles
such as sawdust. They are cylindrical in shape, typically 6 or
8mm wide (diameter), and 15-30mm long.
Note: woody biomass fuels must be stored in a dry environment to minimise the fuel
moisture content level. Logs and wood chip also require a ventilated storage area

Module 1: Heat Producing Technologies
Biomass Fuelled Systems
Biomass Appliances
In this section we look at two main
categories of biomass appliance:
•
•
Biomass stove
Biomass boiler
Each type of appliance has a range of fuel
type and output options
Biomass Stove
Biomass Boiler

Module 1: Heat Producing Technologies
Biomass Fuelled Systems
Biomass stove fuel options
Some biomass stoves burn pellets and some burn
logs.
Pellet burning stoves include a integrated hopper
and an auger feed mechanism that transfers the
pellets from the hopper to the burner when heat is
needed. Log burning stoves require manual loading.
The typical heat capacity range for biomass stoves
is 5- 15kW but some stoves can be regulated to
outputs as low as 2kW

Module 1: Heat Producing Technologies
Biomass Fuelled Systems
Biomass stoves output options

Module 1: Heat Producing Technologies
Biomass Fuelled Systems
Biomass boiler fuel options
Biomass boilers are available for all three main type of
biomass fuel. Some biomass boilers are multi-fuel
boilers.
Pellet burning boilers and wood chip boilers will
include some type of automated feed arrangement to
transfer the fuel to the burner. In many cases and
automated feed arrangement is also used to transfer
the fuel from the store to the appliance. Log burning
boilers require manual loading.
Most biomass boilers also include an automated
arrangement to clean the heat exchanger surfaces

Module 1: Heat Producing Technologies
Biomass Fuelled Systems
Biomass boiler output options
Biomass boilers can provide heat for domestic hot
water and space heating purposes.
The typical minimum heat output rating for biomass
boilers is 8kW for pellet boilers, 12kw for log boilers
and 25kW for wood chip boilers. Biomass boilers are
typically more suited to larger domestic properties,
non-domestic applications and communal heating
schemes.
For smaller domestic properties, a biomass stove that
can provide heat for domestic hot water and space
heating purposes is often used.

Module 1: Heat Producing Technologies
Biomass Fuel Storage and Transfer
For smaller installations, biomass pellets are available in sealed bags that can be carried and
loaded directly into the appliance.
For larger installations with automated fuel transfer, the fuels can either be stored in the
existing building in a room near the boiler, or in a separate store outside the building.
External storage options include an underground store or over ground silo from where the
fuel is fed to the boiler by auger or suction. In underground stores for pellets, it is important
to ensure that no moisture can get in. Stores for chips should be well ventilated to let the
wood dry and prevent mould.
The size of the fuel store depends on many factors: anticipated fuel requirements, fuel type,
reliability of deliveries, space available, delivery vehicle capacity etc.
It is normally cheaper to have large loads of fuel delivered providing suitable storage is
available.
Module 1: Heat Producing Technologies
Biomass Fuelled Systems - some example pellet storage and automated suction feed
arrangements
Module 1: Heat Producing Technologies
Biomass Fuelled Systems
Question
Answer
Why is biomass considered to a carbon neutral
fuel ?
Because the carbon
during combustion is
Clickemitted
here to reveal
used in the growing process for new biomass
fuels.
As well as logs and pellets, what other type of
biomass fuel is available?
Wood Chip
Click here to reveal
What type of biomass appliance is typically the
best type for a small property?
A stove
Click here to reveal
What type of biomass fuel is suitable for
storage in a circular underground storage
tank?
Pellets
Click here to reveal
Module 1: Heat Producing Technologies
Biomass Fuelled Systems – Regulatory Requirements
The installation of a biomass fuelled system will require
compliance with a number of regulatory requirements including
health and safety, electrical regulations and regulations relating to
smoke control. A competent installation contractor will have a
detailed knowledge of these regulations and will ensure
compliance.
Within this section we consider three primary regulatory
requirements in relation to biomass fuelled systems
•
•
•
Building Regulations
Town and Country Planning Regulations
The Clean Air Act and Smoke Control Zones
Note: The requirements stated in this section relate to England and
Wales only. The requirements for Scotland and Northern Ireland
may differ.
Module 1: Heat Producing Technologies
Biomass Fuelled Systems – Regulatory Requirements
The Building Regulations (England and Wales) comprise of 14 parts. Eight of these parts may
have relevance to biomass systems installation.
Part
Topic
Relevance or possible relevance
A
Structure
Where the biomass
appliance
other components
Click
here to and
reveal
put load on the structure
B
Fire Safety
Where holes for pipes
etc. may
reduce the fire
Click here
to reveal
resistant integrity of the building structure
C
Site preparation and resistance to
moisture
Where holes for pipes
reduce the moisture
Click etc.
heremay
to reveal
resistant integrity of the building structure
E
Resistance to the passage of
sound
Where holes for pipes
etc. may
reduce sound proof
Click here
to reveal
integrity of the building structure
G
Sanitation, hot water safety and
water efficiency
Hot water safety Click
and water
efficiency
here to
reveal
J
Combustion appliances and Fuel
Storage system
Biomass appliances
arehere
a heat-producing
combustion
Click
to reveal
appliances and must be installed safely
L
Conservation of fuel and power
Energy efficiency Click
of thehere
system
and the building
to reveal
P
Electrical safety in dwellings
Safe installation of
electrical
controls
Click
here to
revealand components
Module 1: Heat Producing Technologies
Biomass Fuelled Systems – Regulatory Requirements
Town and Country Planning Regulations
Planning permission is not normally needed when installing a biomass fuelled system in a house
if the work is all internal. If the installation requires a flue outside, however, it will normally be
permitted development if the conditions outlined below are met:
•
Flues on the rear or side elevation of the building project to a maximum of one metre
above the highest part of the roof.
If the building is listed or in a designated area even if the building has permitted development
rights it is advisable to check with the local planning authority before a flue is fitted. Consent is
also likely to be needed for internal alterations.
In a conservation area or in a World Heritage site the flue should not be fitted on the principal
or side elevation if it would be visible from a highway.
If the project also requires an outside building to store fuel or related
equipment the same rules apply to that building as for other extensions
and garden outbuildings.
Module 1: Heat Producing Technologies
Biomass Fuelled Systems – Regulatory Requirements
The Clean Air Act and Smoke Control Areas
Under the Clean Air Act, local authorities may declare the whole or part of the district of the
authority to be a smoke control area. It is an offence to emit smoke from a chimney of a
building, from a furnace or from any fixed boiler if located in a designated smoke control area. It
is also an offence to acquire an "unauthorised fuel" for use within a smoke control area unless it
is used in an "exempt" appliance.
The Secretary of State for Environment, Food and Rural Affairs has powers under the Act to
authorise smokeless fuels or exempt appliances for use in smoke control areas in England.
Where a biomass appliance is to be installed to a property located within a smoke control area,
the appliance must be an exempted appliance. The Department for Environment, Food and
Rural Affairs (DEFRA) provides information regarding smoke control areas, exempted appliances
and exempted fuels. The information is available at http://smokecontrol.defra.gov.uk/
Module 1: Heat Producing Technologies
Biomass Fuelled Systems - Building location and feature requirements
For the potential to install to a biomass fuelled system to exist, as a
minimum some or all of the following building and location factors will
need to be considered:
•
A suitable flue or chimney system or the potential to install a
suitable flue or chimney system. The flue system must be
constructed of, or lined with a material that is a suitable to receive
the products of combustion from a biomass appliance. Prefabricated
gas appliance flue systems are not suitable for biomass appliances.
The flue must also be fitted with and appropriate terminal to
disperse the products of combustion.
•
A suitable location and arrangement for fuel storage. Factors such a
space, moisture, access for fuel deliveries and the frequency of fuel
deliveries must be considered.
Module 1: Heat Producing Technologies
Biomass Fuelled Systems
Question
Answer
Is the installation of a biomass stove in a house
classified as permitted development under the
Town and Country Planning Regulations?
Yes providing: Click here to reveal
Flues on the rear or side elevation of the house
project no more than one metre above the
highest part of the roof.
The house is not listed, not in a designated area
not in a conservation area or in a World Heritage
site
What is an ‘exempted appliance’?
An appliance that
is permitted
for use in a Smoke
Click
here to reveal
Control Area
What does DEFRA stand for?
The Department
for here
Environment,
Click
to reveal Food and
Rural Affairs
How did you do?
Module 1: Heat Producing Technologies
Biomass Fuelled Systems – Advantages and Disadvantages
Some example advantages and disadvantages are:
Advantages
Disadvantages
Biomass is a carbon neutral technology
Requires a suitable flue/chimney system
Does not rely on building orientation or
weather conditions to operate effectively
Initial installation costs can be off-putting
Biomass is generally considered to be an
inexhaustible fuel source
Typically require a large space to store fuel
The cost of producing biomass for use as fuels
and energy sources is very cheap compared to
the cost of finding and extracting fossil fuels
Sometimes considered less suitable for
smaller properties
Well Done! You have now completed the biomass fuelled systems section.
Click on the forward arrow to return to heat producing technology system menu page
Module 2: Electricity Producing Technologies
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems
Objectives
At the end of this section you will:
•
•
•
•
understand the fundamental working principles of solar photovoltaic systems
recognise the top level regulatory requirements that apply in relation to solar
photovoltaic systems installation work
recognise the fundamental requirements of building location and building features
for the potential to install to a solar photovoltaic system to exist
recognise the typical advantages and disadvantages of solar photovoltaic systems

Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – Introduction
In basic terms a solar photovoltaic system is a system
that uses solar cells to convert light energy from
the sun into electricity.
Solar cells are semiconductors -typically silicon. A
group of solar cells is known as a solar photovoltaic
module
Photons in sunlight hit the solar cells and are
absorbed by the cell. This process causes the
negatively charged electrons within the solar cell to
come loose from their atoms allowing them to flow
through the cell to produce electricity. The
electricity that is produced is direct current (d.c.) –
the type of electricity that is produced by a battery.
solar photovoltaic module
Solar photovoltaic is a zero carbon technology.
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – Basic System Categories
Although there are a number of system types,
variations and configurations, solar photovoltaic
systems fall into two basic system categories:
•
•
‘on-grid’ systems
‘off-grid systems
‘on-grid’
‘On-grid’ systems allow any surplus electricity that
is generated to be exported to the electricity
distribution grid. This type of system is very
popular since the introduction of the Feed-in Tariff
scheme
‘Off-grid’ systems use a battery bank arrangement
to store the electrical power generated for use
when needed.
Some system installations will combine ‘on and ‘off’ grid arrangements
‘off-grid’
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – Direct Current and Alternating Current
Some electrical appliances operate using direct current
electricity, but the most common type of electricity used in our
homes and places of work etc. is alternating current.
Before direct current (d.c) electricity that is generated by a solar
photovoltaic system can be used with alternating current (a.c.)
systems and appliances, the electricity has to be converted from
d.c. to a.c. electricity.
It is only possible to export alternating current (a.c.) electricity
to the electricity distribution grid. Therefore on-grid a.c. solar
photovoltaic systems are the most popular an common type of
system.
Let’s now look at the typical layout of an ‘on-grid’ solar
photovoltaic system in more detail.
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems - Components (‘on-grid’ systems)
Click on each number for a
brief overview
1
2
4
3
Please note that due to the
intended purpose of this learning
tool, some system components are
not shown. This is not an
installation diagram.
Module 2: Electricity Producing Technologies
Solar Photovoltaic System Components - Solar Photovoltaic Module
Sometimes referred to as a solar photovoltaic panel, solar photovoltaic
modules are mounted in a suitable location - often on a building where they will receive the maximum amount of solar light energy.
As previously explained, solar photovoltaic modules contain
solar cells that convert light energy from the sun into electricity.
A group of solar modules is known as an solar array.
A range of different solar photovoltaic modules
(monocrystaline, polycrystaline, thin-film etc.) are available,
each type having different levels of efficiency.
Roof mounted solar photovoltaic modules can be mounted on the
surface of the roof using a rail system or integrated into the roof
surface. Some manufacturers also make solar photovoltaic roof tiles.
Module 2: Electricity Producing Technologies
Solar Photovoltaic System Components - Inverter
The inverter is the system component that converts
the direct current (d.c.) to alternating current (a.c).
Depending upon the photovoltaic module array layout
and size, the d.c voltages that enter the inverter can be
very high.
The inverter can be mounted in the roof area adjacent
to the PV module location or in the building.
Module 1: Heat Producing Technologies
Solar Photovoltaic System Components – Consumer Unit
The consumer unit or fuse board as it is sometimes
referred to is used to as the connection point for the solar
photovoltaic system installation. .
Where the existing consumer unit is of a modern type, and
has a spare connection circuit point available, it can often
be utilized. Older type consumer units will need to be
replaced at the time that the solar photovoltaic system is
installed.
Module 2: Electricity Producing Technologies
Solar Photovoltaic System Components – Generation Meter
A generation meter is fitted to record how much solar
generated electricity has been exported to the supply grid.
Some energy supplier’s incoming supply (import) meter
have the capability to perform this function but a
generation meter is typically included as part of the solar
photovoltaic installation.
The generation meter must be of an approved type and
located in a position where it is easily accessible for
reading purposes.
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems
Question
Answer
Where is a semiconductor material used in a
solar photovoltaic system?
In a solar cell Click here to reveal
What is the most popular type of solar
photovoltaic systems?
‘On-grid’ systems
Click here to reveal
What is a solar photovoltaic array?
heresolar
to reveal
A group of two Click
or more
photovoltaic
modules
What is the function of a solar photovoltaic
system inverter?
To convert the d.c.
electricity
Clickelectrical
here to reveal
generated by the solar photovoltaic array into
a.c. electricity
How did you do?
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – Regulatory Requirements
The installation of a solar photovoltaic system will require
compliance with a number of regulatory requirements including
health and safety, electrical regulations and regulations relating to
the connection of ‘on-grid’ solar photovoltaic systems. A
competent installation contractor will have a detailed knowledge
of these regulations and will ensure compliance.
Within this section we consider two primary regulatory
requirements in relation to solar photovoltaic systems:
•
•
Building Regulations
Town and Country Planning Regulations
Note: The requirements stated in this section relate to England and
Wales only. The requirements for Scotland and Northern Ireland
may differ.
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – Regulatory Requirements
The Building Regulations (England and Wales) comprise of 14 parts.
Five of these parts have relevance to solar photovoltaic systems installation.
Part
Topic
Relevance or possible relevance
A
Structure
Where solar photovoltaic
and other components
Click modules
here to reveal
put load on the structure, in particular wind uplift loads
B
Fire Safety
Where holes for cables
etc.
maytoreduce
Click
here
revealthe fire resistant
integrity of the building structure
C
Site preparation and
resistance to moisture
Where holes for cables
etc.here
maytoreduce
Click
revealthe moisture
resistant integrity of the building structure
E
Resistance to the passage
of sound
Where holes for cables
etc.here
maytoreduce
Click
revealsound proof integrity
of the building structure
P
Electrical safety in
dwellings
Safe installation of electrical
controls
and components
Click here
to reveal
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – Regulatory Requirements
Town and Country Planning Regulations – Building Mounted Arrays
The installation of building mounted solar photovoltaic arrays is typically classed as permitted
development providing :
•
•
•
•
•
the solar modules are not installed above the ridgeline and do not project more than
200mm from the roof or wall surface.
the solar modules are sited, so far as is practicable, to minimise the effect on the
appearance of the building
the solar modules are sited, so far as is practicable, to minimise the effect on the amenity
of the area.
the property is not a listed building*
the property is not in a conservation area or in a World Heritage Site
The Local Planning Authority should be consulted for clarification, particularly for
installations to flats and non-dwelling building types.
*Listed Building Consent may be required even if planning permission is not
required.
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – Regulatory Requirements
Town and Country Planning Regulations – Stand-alone Arrays
The installation of a stand-alone solar photovoltaic arrays is typically classed as permitted
development providing :
•
•
•
•
•
•
The array is no higher than four metres
The array is sited at least 5m from boundaries
The size of array is limited to 9m2 or 3m wide and 3m deep
The array is not being installed within boundary of a listed building
In the case of land in a conservation area or in a World Heritage Site the array will not be
visible from the highway.
Only one stand-alone solar installation is being installed.
*Listed Building Consent may be required even if planning permission is not
required.
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems - Building location and feature requirements
For the potential to install to a solar photovoltaic system to exist, as
a minimum some or all of the following building and location factors
will need to be considered:
•
•
•
•
orientation of the solar photovoltaic array
tilt solar photovoltaic array
adjacent structures or obstructions that introduce overshading
the availability of a suitable solar photovoltaic array mounting
structure
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – building location and feature requirements
Orientation
In the UK, we tend to relate a south
facing garden in our homes to the
availability of the most sunshine
throughout the day. Well the same
applies in relation to solar
photovoltaic systems.
The ideal orientation is south facing.
Orientations between south east and
south west will also provide good
results.
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – building location and feature requirements
Solar Photovoltaic Array Tilt
As well as orientation, the ‘tilt’ of the solar
photovoltaic array is also key factor that determines
the amount of solar energy that is harnessed from the
sun and converted to electrical energy.
‘Tilt’ is the angle that the solar photovoltaic array is
mounted from the horizontal plane.
Where a pitched roof already exists, the tilt is typically
determined by the roof pitch.
Where there is no pitched roof available, it is possible to mount solar photovoltaic arrays on
vertical and horizontal surfaces. Solar photovoltaic array may also be mounted on purpose built
support frames to provide the required tilt.
Typically, a tilt of between 30o and 40o from horizontal is considered to be close to optimum
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – building location and feature requirements
Optimum Orientation and Tilt
Orientation
Tilt from horizontal (o)
East
South
West
-90
-75
-60
-45
-30
-15
0
15
30
45
60
75
90
90
56
60
64
67
69
71
71
71
71
69
65
62
58
80
63
68
72
75
77
79
80
80
79
77
74
69
65
70
69
74
78
82
85
86
87
87
86
84
80
76
70
60
74
79
84
87
90
91
93
93
92
89
86
81
76
50
78
84
88
92
95
96
97
97
96
93
89
85
80
40
82
86
90
95
97
99
100
99
98
96
92
88
84
30
86
89
93
96
98
99
100
100
98
96
94
90
86
20
87
90
93
96
97
98
98
98
97
96
94
91
88
10
89
91
92
94
95
95
96
95
95
94
93
91
90
0
90
90
90
90
90
90
90
90
90
90
90
90
90
‘Solar sundial showing the likely yield (%) of optimum for different orientation and tilt arrangements
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – building location and feature requirements
Overshading
Any overshading of the solar photovoltaic array will
have an impact on much solar energy is harnessed
from the sun and converted to electrical energy.
Heavy overshading will reduce the performance of
the system by approximately 50% during peak
irradiation. Modest overshading will reduce
performance by approximately 20%,
Overshading can also lead to thermal stress in solar
photovoltaic modules causing malfunctioning to
occur, possibly leading to early component failure.
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – building location and feature requirements
Suitable Solar Photovoltaic Array Mounting Structure
The solar photovoltaic array mounting structure must be suitable in terms of
being:
•
of sufficient size (m2)
− The required area will vary according to the module efficiency.
Typically a minimum of 8m2 of suitable array mounting area is
needed for each 1000 watts of electricity generation under peak
conditions (1 kWp or kilo-watt peak)
•
strong enough to support the array
− as well as considering the the potential for collapse or damage under
normal conditions, additional factors such as wind uplift loads and
snow loading will also need to be considered
•
in good condition
− there is no sense in installing a solar photovoltaic array to a roof that
is in a poor state of repair. Any repairs or refurbishment should be
carried out prior to installing the array
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems
Question
Answer
What is the optimum orientation for a solar
photovoltaic array in the UK?
South facing
What is the optimum tilt angle for a solar
photovoltaic array?
Between 30o and
40ohere
fromtothe
horizontal plane
Click
reveal
What effect will overshading have on a solar
photovoltaic array?
Reduce performance
(andtopossibly
Click here
reveal lead thermal
stress and malfunctioning)
What are the essential requirements for a
structure to be suitable for the mounting of a
solar photovoltaic array ?
1.
2.
3.
How did you do?
Click here to reveal
Sufficient size
Click here to reveal
Strong enough
In good condition
Module 2: Electricity Producing Technologies
Solar Photovoltaic Systems – Advantages and Disadvantages
Some example advantages and disadvantages are:
Advantages
Disadvantages
It is a zero carbon technology
Requires a relatively large array area to make
the installation worthwhile
The technology qualifies for Feed-In Tariff
payments
Initial installation costs can be off-putting
Most buildings are suitable for the technology
Variable performance according to the
availability of solar energy
Improves Energy Performance Certificate
ratings
Some people consider that solar photovoltaic
arrays reduce the appearance of the building
Well Done! You have now completed the solar photovoltaic systems section.
Click on the forward arrow to return to the electricity producing technology system menu page
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems
Objectives
At the end of this section you will:
•
•
•
•
understand the fundamental working principles of micro-wind turbine systems
recognise the top level regulatory requirements that apply in relation to micro-wind
turbine systems installation work
recognise the fundamental requirements of building location and building features
for the potential to install to a micro-wind system to exist
recognise the typical advantages and disadvantages of micro-wind systems

Module 2: Electricity Producing Technologies
Micro-Wind Systems – Introduction
Micro-wind systems make use of the natural wind
resource to generate electrical energy
A basic wind turbine operates on the principle that wind
passing across the rotor blades of a turbine cause a ‘lift’
and ‘drag’ effect which in-turn causes the hub to turn.
The hub is connected by a low-speed shaft to a gearbox
which increases the speed of rotation of the shaft. The
high-speed shaft is connected to a generator that
produces electricity.
Basic horizontal axis wind turbine
Module 2: Electricity Producing Technologies
Micro-Wind Systems – Introduction
The horizontal axis wind turbine (HAWT) that we
have just seen is the most common type of turbine.
Vertical axis wind turbines (VAWT) are also available.
Vertical axis wind turbines accept wind from any
direction and do not include the tailfin detail that is
included on horizontal axis turbines.
This type of turbine also includes a gearbox and
generator.
Basic vertical axis wind turbine
Module 2: Electricity Producing Technologies
Micro-wind Turbine Systems – Basic System Categories
Although there are a number of system types,
variations and configurations, micro-wind turbine
systems fall into two basic system categories:
•
•
‘on-grid’ systems
‘off-grid systems
‘on-grid’
‘On-grid’ systems allow any surplus electricity that
is generated to be exported to the electricity
distribution grid. This type of system is included in
the Feed-in Tariff scheme
‘Off-grid’ systems use a battery bank arrangement
to store the electrical power generated for use
when needed.
Some system installations will combine ‘on and ‘off’ grid arrangements
‘off-grid’
Module 2: Electricity Producing Technologies
Micro -Wind Turbine Systems – ‘Wild Current’
Most micro and small scale wind turbines (less than 20 kilowatt
(kW)) produce "wild" (variable voltage and frequency)
alternating current (AC) electricity which is rectified to direct
current (DC) via a system controller. This DC is then either
directly used to charge batteries or is converted using an
inverter to normal AC (240V 50Hz).
Let’s now look at the typical layout of an ‘on-grid’ micro-wind
system in more detail.
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems
Typical ‘on-grid’ micro-wind turbine system
It is also possible to mount micro-wind turbines directly onto the building, although this is not
recommended for small buildings or for premises where noise and flicker may be an issue
Please note that due to the intended purpose of this learning tool, some system components are not shown.
This is not an installation diagram.
Module 2: Electricity Producing Technologies
Micro -Wind Turbine Systems
Question
Answer
What are the main types of micro-wind
turbine?
Horizontal axis wind
turbines
(HAWT) and
Click here
to reveal
vertical axis wind turbines (VAWT)
What type of wind turbine accepts wind from
any direction?
A vertical axis wind
Clickturbine
here to (VAWT)
reveal
What is a micro-wind turbine system battery
pack used for?
Click here
to has
reveal
To store the electricity
that
been generated
by the turbine until it is needed
What options are there for mounting a microwind turbine ?
Mast mounted or
building
Click
here tomounted
reveal
How did you do?
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems – Regulatory Requirements
The installation of environmental technology systems will require
compliance with a number of regulatory requirements including
health and safety, electrical regulations and regulations relating to
the connection of ‘on-grid’ micro-wind turbine systems. A
competent installation contractor will have a detailed knowledge
of these regulations and will ensure compliance.
Within this section we consider two primary regulatory
requirements in relation to micro-wind turbine systems :
•
•
Building Regulations
Town and Country Planning Regulations
Note: The requirements stated in this section relate to England
and Wales only. The requirements for Scotland and Northern
Ireland may differ.
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems – Regulatory Requirements
The Building Regulations (England and Wales) comprise of 14 parts.
Five of these parts may have relevance to micro-wind turbine systems installation.
Part
Topic
Relevance or possible relevance
A
Structure
Where micro-wind
turbines
are mounted on
Click here
to reveal
buildings and put load on the structure
B
Fire Safety
Where holesClick
for cables
etc.
may reduce the
here to
reveal
fire resistant integrity of the building
structure
C
Site preparation and resistance to
moisture
Where holesClick
for cables
etc.reveal
may reduce the
here to
moisture resistant integrity of the building
structure
E
Resistance to the passage of sound
Where holesClick
for cables
may reduce
here etc.
to reveal
sound proof integrity of the building
structure
P
Electrical safety in dwellings
Safe installation
ofhere
electrical
controls and
Click
to reveal
components
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems – Regulatory Requirements
Town and Country Planning Regulations
The installation of micro-wind turbines is not classed as permitted development.
At present planning permission is nearly always required to install a micro-wind turbine to a
building, or grounds surrounding a building.
Factors that may affect whether permission is granted or not include:
•
•
•
•
•
visual impact
noise
vibration
electrical interference (with TV aerials)
safety
The Government is currently reviewing the planning requirements for
micro-wind turbines and it is possible that some permitted development
will be included in the future.
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems - Building location and feature requirements
For the potential to install to a micro-wind turbine system to exist, as
a minimum some or all of the following building and location factors
will need to be considered:
•
•
•
•
average wind speed
height at which the turbine can be mounted
obstructions and turbulence
a location that will not be affected by turbine noise, vibration
and flicker
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems - Building location and feature requirements
Average Wind Speed
The average wind speed is a critical factor in determining the
viability of a micro-wind turbine system. Wind speed is measure in
metres per second (m/s)
Whilst micro-wind turbines will typically start generating
electricity at 3-4 m/s, the minimum viable wind speed is 5 m/s.
Most micro-wind turbines will reach their maximum rated output
at between 10-14 m/s so this is the ideal wind speed range.
Wind speed can be measured on-site using an anemometer but if
this is done measurements should be taken over a period of
months to be accurate.
There is a national wind speed database but this database is no
longer being updated. The database also has limitations in terms
of its relevance to micro-wind turbine installations.
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems - Building location and feature requirements
Height, Obstruction and Turbulence Considerations
As wind speed typically increases with height, the basic principle is the higher the
mounting location the better.
A high mounting location with a smooth prevailing wind flow is ideal.
To minimise the effect of turbulence, micro-wind turbines should ideally be mounted
at a distance equal to 10 times the height of the nearest obstruction
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems - Building location and feature requirements
Noise, Vibration and Flicker Considerations
All wind turbines will generate some degree of
noise, vibration and shadow flicker which caused
by the sun passing across the turbine rotor blades
as it spins.
These factors are much less of a consideration
when the micro-wind turbine can be located away
from buildings.
Where a micro-wind turbine is to be building
mounted, careful consideration must be given to
these factors.
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems
Question
Answer
Which part of the Building Regulations need to
be considered when a micro-wind turbine is to
be mounted directly onto a building ?
Click here to reveal
Part A - Structure
Is a micro-wind turbine installation classified as
permitted development?
No – planning permission
is reveal
normally required
Click here to
What is the minimum recommended average
wind speed for a micro-wind turbine?
5 m/s
Click here to reveal
What is the ideal average wind speed range for
a micro-wind turbine?
10 to 14 m/s
Click here to reveal
How did you do?
Module 2: Electricity Producing Technologies
Micro-Wind Turbine Systems – Advantages and Disadvantages
Some example advantages and disadvantages are:
Advantages
Disadvantages
It is a zero carbon technology
Requires a suitable mounting site, ideally well
away from buildings and obstructions
The technology qualifies for Feed-In Tariff
payments
Initial installation costs can be off-putting
Micro-wind turbine electricity generation
output levels can be very good in the UK which
has 40% of Europe’s wind resource
Variable performance according to the
availability of wind
Can be a very effective technology where no
mains electricity is available
Micro-wind turbines can cause noise,
vibration and flicker problems
Well Done! You have now completed the micro-wind turbine systems section.
Click on the forward arrow to return to the electricity producing technology system menu page
Module 2: Electricity Producing Technologies
Micro-Hydropower Systems
Objectives
At the end of this section you will:
•
•
•
•
understand the fundamental working principles of micro-hydropower systems
recognise the top level regulatory requirements that apply in relation to microhydropower systems installation work
recognise the fundamental requirements of building location and building features
for the potential to install to a micro-hydropower system to exist
recognise the typical advantages and disadvantages micro-hydropower systems

Module 2: Electricity Producing Technologies
Micro-Hydropower Systems – Introduction
Micro-hydropower systems make use of the natural
water resource to generate electrical energy
A micro-hydropower turbine operates on the
principle that water passing across or through a
turbine causes the turbine to rotate. The turbine
shaft is connected to a generator that converts the
hydropower to electrical energy
Micro-hydropower is a zero carbon technology.
Module 2: Electricity Producing Technologies
Micro-Hydropower Systems – Basic System Categories
Although there are a number of system types,
variations and configurations, micro-hydropower
turbine systems fall into two basic system
categories:
•
•
‘on-grid’ systems
‘off-grid systems
‘on-grid’
‘On-grid’ systems allow any surplus electricity that
is generated to be exported to the electricity
distribution grid. This type of system is included in
the Feed-in Tariff scheme
‘Off-grid’ systems use a battery bank arrangement
to store the electrical power generated for use
when needed.
‘off-grid’
Module 2: Electricity Producing Technologies
Micro–Hydropower System – Basic principles
Water is taken from a high level
watercourse or other source via a
purpose made inlet.
The water passes through a pipe known
as a ‘penstock’ to reach the turbine unit.
As water passes through the turbine the
hydropower is harnessed and electricity
is generated.
As water leaves the turbine unit it is
returned to the watercourse or another
discharge to a suitable location via a
outlet known as a tailrace.
Module 2: Electricity Producing Technologies
Micro-Hydropower Systems - Building location and feature requirements
For the potential to install to a micro-hydropower system to exist,
the key requirements are:
•
•
•
•
•
the availability of a water course (river, stream etc.)
the ability to achieve adequate ‘hydraulic head’ an ‘flow’ within
the system design
a suitable location for an inlet
a suitable location for the turbine and generator
a suitable location for the tailrace outlet
Adequate ‘hydraulic head’ an ‘flow’ is also a key factor that will
determine the type of micro-hydropower turbine that can be used.
Module 2: Electricity Producing Technologies
Micro–Hydropower Systems – Head and Flow
Head = the vertical distance
between the upper and lower
water levels or the vertical
distance between the intake
and turbine
Flow = the quantity of water
that is moving over a given
period of time
Module 2: Electricity Producing Technologies
Micro-Hydropower Systems - Turbine Classification
Micro-hydropower turbines are classified according to their ability to operate in high,
medium or low head conditions and also are classified being either an ‘impulse’ turbines or
a ‘reaction’ turbine according to how they operate:
•
Impulse turbine – where the turbine wheel or runner is surrounded by air and the
turbine is moved by the impulse created by a jet or ‘jets’ of water that is aimed at the
turbine. Types of impulse turbine include Pelton, Multi-jet Pelton, Turgo, Cross-flow.
•
Reaction turbine - where the turbine wheel or runner is fully immersed in water and
the turbine is moved in reaction to flow of the water Types of reaction turbine include
Francis (spiral case), Francis (open-flume), Propeller and Kaplan
Module 2: Electricity Producing Technologies
Micro–Hydropower Systems – Example Pelton Type ‘Impulse’ Turbine
Module 2: Electricity Producing Technologies
Micro–Hydropower Systems – Example Horizontal Francis Type ‘Reaction’ Turbine
Plan view
Side view
Module 2: Electricity Producing Technologies
Micro–Hydropower Systems – Example turbine applications in relation to available head of
water
Turbine Type
Impulse
Reaction
Head Classification
High
(> 50m)
Medium
(10 to 50m)
Low
(> 10m)
Pelton
Turgo
Multi-jet Pelton
Crossflow
Turgo
Multi-jet Pelton
Crossflow
Francis (Spiral Case)
Francis (open-flume)
Propeller
Kaplan
Module 2: Electricity Producing Technologies
Micro–Hydropower Systems – Example ‘Reverse Archimedian Screw’ Type Turbine
The ‘Reverse Archimedian Screw’ is an alternative type of turbine that is sometimes
used for larger micro-hydropower schemes. This type of turbine is particularly suitable
for low head installations and is also ‘fish friendly’ allowing fish and eels to pass through
without injury.
Module 2: Electricity Producing Technologies
Micro–Hydropower Systems
Question
Answer
here
to inlet
revealto the turbine
What is the purpose of a the ‘penstock ‘in To carry waterClick
from
the
a micro-hydropower system
After the availability of a water course,
what is the next key factor that will
determine the potential for a microhydropower installation?
Click here
toand
reveal
Suitable hydraulic
head
suitable flow
Which type of turbine operates using a
jet or ‘jets’ of water ?
Click here to reveal
An impulse turbine
What type of turbine is most likely to be
considered as ‘fish friendly’?
Click here toscrew
revealturbine
A reverse archimedian
How did you do?
Module 2: Electricity Producing Technologies
Micro-Hydropower Systems – Regulatory Requirements
The installation of a micro-hydropower system will require
compliance with a number of regulatory requirements including
health and safety, electrical regulations and regulations relating to
the connection of ‘on-grid’ micro-hydropower systems. A
competent installation contractor will have a detailed knowledge
of these regulations and will ensure compliance.
Within this section we consider three primary regulatory
requirements in relation to micro-hydropower systems:
•
•
•
Building Regulations
Town and Country Planning Regulations
Environmental Regulations
Note: The requirements stated in this section relate to England and
Wales only. The requirements for Scotland and Northern Ireland
may differ.
Module 2: Electricity Producing Technologies
Micro-Hydropower Systems– Regulatory Requirements
The Building Regulations (England and Wales) comprise of 14 parts.
Five of these parts may have relevance to micro-hydropower systems installation, depending
upon the actual installation details and arrangements. Where a micro-hydropower systems is
partly installed in or connected to a habitable building some or all of the following may apply.
Part
Topic
Relevance or possible relevance
A
Structure
Clickmicro-hydropower
here to reveal
Where any part of the
system puts
load on the structure
B
Fire Safety
Where holes for cables
reduce the fire resistant
Click etc.
heremay
to reveal
integrity of the building structure
C
Site preparation and
resistance to moisture
Clicketc.
heremay
to reveal
Where holes for cables
reduce the moisture
resistant integrity of the building structure
E
Resistance to the passage
of sound
Where holes for cables
reduce sound proof
Clicketc.
heremay
to reveal
integrity of the building structure
P
Electrical safety in
dwellings
Safe installation of electrical
Click herecontrols
to revealand components in
dwellings
Module 2: Electricity Producing Technologies
Micro-Hydropower Systems – Regulatory Requirements
Town and Country Planning Regulations
As we have identified, the key features of a micro-hydropower scheme include:
•
•
•
•
•
a hydraulic 'head' - vertical distance from water source to the turbine.
a water intake
a pipe or channel to take water to the turbine
a turbine, generator and electrical connection
an outflow, where the water returns to the watercourse
These elements raise a number of important planning issues and planning permission will usually
be needed. The elements of a small-scale hydro electricity scheme create potential impacts on:
•
•
•
landscape and visual amenity
nature conservation
the water regime.
Some form of environmental assessment is also essential when it comes to
applying for planning permission and environmental licenses.
Module 2: Electricity Producing Technologies
Micro-Hydropower Systems– Regulatory Requirements
Environmental Regulations – Licences
All water courses of any size in England and Wales are controlled by the Environment Agency.
To remove water from them (even though it may go back in) will almost certainly require
their permission in the form of a licence. There are three licences that can apply to a
hydropower scheme:
•
Abstraction Licence - if water is being diverted ‘away from the main line of flow of the
river’. Part of the consideration will be fish migration. Most micro-hydropower turbines
are not ‘fish friendly’ so where fish migration is a factor, an abstraction licence will only
be issued with conditions stating the requirement for fish screens and a fish pass
arrangement
•
Impoundment Licence - if changes are being made to structures which impound water,
such as weirs and sluices, or if new structures are to be built.
•
Land Drainage Consent - for any works being carried out in a ‘main channel’
Module 2: Electricity Producing Technologies
Micro-Hydropower Systems– Regulatory Requirements
Environmental Regulations
It is necessary to carry out a Environmental Site Audit (ESA) as part of the process of
identifying the suitability of a micro-hydropower installation. The ESA covers the following
areas:
•
•
•
•
•
•
•
Water resources
Conservation
Chemical and physical water quality
Biological water quality
Fisheries
Flood risk
Navigation
The Environment Agency must always be consulted as early as possible when
a micro-hydropower installation is being considered.
Module 2: Electricity Producing Technologies
Micro–Hydropower Systems
Question
Answer
Is a micro-hydropower installation classified as
‘permitted development’ under the Town and
Country Planning Regulations?
No – the local planning
authority
Click here
to revealmust be
consulted
What is an Abstraction Licence?
A licence that authorises
temporary or
Click here the
to reveal
permanent extraction of water from a water
course
Which body would issue an Abstraction
Licence?
Click
here to reveal
The Environment
Agency
What type of audit must be carried out as part
of the process to decide is a micro-hydropower
installation is possible?
Click
here
to reveal
An Environmental
Site
Audit
How did you do?
Module 2: Electricity Producing Technologies
Micro–Hydropower Systems – Advantages and Disadvantages
Some example advantages and disadvantages are:
Advantages
Disadvantages
It is a zero carbon technology
Requires a watercourse with suitable head
and flow
The technology qualifies for Feed-In Tariff
payments
Initial installation costs can be off-putting
Excellent payback potential
Usually requires planning permission and
Can be a very effective technology where no
mains electricity is available
Requires permission from the Environment
Agency
Well Done! You have now completed the micro-hydropower systems section.
Click on the forward arrow to return to the electricity producing technology system menu page
Module 3: Co-generation Technologies
Module 3: Cogeneration Technologies
Micro-Combined Heat and Power Systems (Heat Led)
Objectives
At the end of this section you will:
•
•
•
•
•
understand the fundamental working principles of a heat-led micro-combined heat
and power system
recognise the top level regulatory requirements that apply in relation to a heat-led
micro-combined heat and power system installation work
recognise the fundamental requirements of building location and building features
for the potential to install to a heat-led micro-combined heat and power system
to exist
recognise the typical advantages and disadvantages a heat-led micro-combined
heat and power system

Module 3: Co-generation Technologies
Micro-Combined Heat and Power Systems (Heat Led) - Introduction
A heat-led micro-combined heat and power (mCHP) system
includes a mCHP unit, similar in appearance to a heating
system boiler, that generates some electricity as well as
generating heat for domestic hot water and space heating
purposes.
The term ‘heat-led’ means that the generation of the
electricity occurs when the unit is responding to a system
demand for heat and that the majority of output from the
unit is for heating purposes.
Although mCHP units have existed for some time, units
suitable for domestic installations have only recently become
available. The currently available domestic units are gasfired only. Other fuels options may be available for nondomestic units.
MCHP is a low carbon technology and the units are typically
up to 95% efficient.
Typical mCHP System
Energy Flows
Module 3: Co-generation Technologies
Micro-Combined Heat and Power Unit Components
The key mCHP unit internal components
are:
•
•
•
•
•
•
an engine or gas turbine
an alternator
two heat exchangers
a supplementary burner
a combustion fan
electrical controls (not illustrated)
mCHP units can contain any of the
following engine types
•
Example mCHP Unit
•
•
External combustion (Stirling type
illustrated )
Internal combustion
Organic rankine cycle
Module 3: Co-generation Technologies
Micro-Combined Heat and Power Unit Operation (Stirling Engine Unit)
When demand for heat occurs, a gas burner
provides heat to the Stirling engine unit
causing the Stirling engine to operate.
The Stirling engine unit includes a generator
comprising a piston that moves between a
copper coil. As the Stirling engine operates
electricity is generated providing the engine
runs for a minimum period of time and does
not cycle on and off.
There is a limit (typically 25% of total unit
output) to the amount of heat that can be
provided during the operation of the Stirling
engine.
When additional heat is needed to meet higher
demand, the supplementary burner operates.
Module 3: Co-generation Technologies
Micro-Combined Heat and Power Unit – Electrical Output and System Connections
A domestic mCHP unit will typically generate between
1kW and 1.5kW of electricity. Larger mCHP units
typically generate up to 5-6 kW of electricity.
The preferred connection arrangement between the
mCHP unit and the main electricity system is using a
dedicated circuit from/to the consumer unit (Option 1).
Where this is difficult, it is possible to connect the unit
to an existing final circuit (Option 2).
Any surplus electricity can be exported to the
distribution grid. mCHP installations are eligible for
Feed-In Tariff payments providing the installation is
carried out by a Microgeneration Certification Scheme
MCS) certified contractor using an MCS approved unit.
All electrical work must be designed, installed and tested by a competent person.
Module 3: Co-generation Technologies
Micro-Combined Heat and Power Systems
Question
Answer
How does a mCHP unit generate electricity?
Using a generator
connected
to an engine or
Click
here to reveal
turbine
Approximately, what percentage of the energy
produced by a mCHP unit is electrical energy ?
15%
Click here to reveal
What is the maximum efficiency of a mCHP
unit?
95%
Click here to reveal
Are mCHP installations eligible for Feed-in Tariff
payments?
Click
here to reveal
Yes - providing the
installation
is carried out by a
Microgeneration Certification Scheme MCS)
certified contractor using an MCS approved unit
How did you do?
Module 3: Co-generation Technologies
Micro-Combined Heat and Power Systems – Regulatory Requirements
The installation of a micro-combined heat an power system will
require compliance with a number of regulatory requirements
including health and safety, electrical regulations and regulations
relating to the connection of ‘on-grid’ micro-combined heat and
power systems. A competent installation contractor will have a
detailed knowledge of these regulations and will ensure compliance.
Within this section we consider two primary regulatory requirements
in relation to micro-combined heat and power systems
•
•
Building Regulations
Town and Country Planning Regulations
Note: The requirements stated in this section relate to England and
Wales only. The requirements for Scotland and Northern Ireland may
differ.
Module 3: Co-generation Technologies
Micro-Combined Heat and Power Systems – Regulatory Requirements
The Building Regulations (England and Wales) comprise of 14 parts.
Eight of these parts may have relevance to micro-combined heat and power systems installation.
Part
Topic
Relevance or possible relevance
A
Structure
Where the mCHPClick
unit and
components put
hereother
to reveal
load on the structure
B
Fire Safety
Where holes for pipes
reduce the fire
Click etc.
heremay
to reveal
resistant integrity of the building structure
C
Site preparation and resistance to
moisture
Where holes for pipes
etc. may
reduce the moisture
Click here
to reveal
resistant integrity of the building structure
E
Resistance to the passage of
sound
Where holes for pipes
etc. may
reduce sound proof
Click here
to reveal
integrity of the building structure
G
Sanitation, hot water safety and
water efficiency
Hot water safety Click
and water
here efficiency
to reveal
J
Combustion appliances and Fuel
Storage system
mCHP units are aClick
heat-producing
combustion
here to reveal
appliance and must be installed safely
L
Conservation of fuel and power
Energy efficiencyClick
of thehere
system
and the building
to reveal
P
Electrical safety in dwellings
Safe installation of
electrical
Click
here tocontrols
reveal and components
Module 3: Co-generation Technologies
Micro-Combined Heat and Power Systems – Regulatory Requirements
Town and Country Planning Regulations
Planning permission is not normally needed when installing a micro-combined heat and power
system in a house if the work is all internal. If the installation requires a flue outside, however, it
will normally be permitted development if the conditions outlined below are met:
•
Flues on the rear or side elevation of the building project to a maximum of one metre
above the highest part of the roof.
If the building is listed or in a designated area even if the building has permitted development
rights it is advisable to check with the local planning authority before a flue is fitted. Consent is
also likely to be needed for internal alterations.
In a conservation area or in a World Heritage site the flue should not be fitted on the principal
or side elevation if it would be visible from a highway.
If the project also requires an outside building to store fuel or related
equipment the same rules apply to that building as for other extensions
and garden outbuildings.
Module 3: Co-generation Technologies
Micro-Combined Heat and Power Systems - Building location and feature requirements
For the potential to install to a micro-combined heat and power system
to exist, as a minimum some or all of the following building and location
factors will need to be considered:
•
A suitable route and termination point for the mCHP unit flue
system
•
A suitable heat-demand – heat-led mCHP units only generate
electricity when the unit engine is able to run for a minimum period
of time. Additionally, the unit will not be as efficient if the unit
cycles ‘on and ‘off’ Small dwellings and dwelling with low heat
demand are not suitable for heat-led mCHP.
Module 3: Co-generation Technologies
Micro-Combined Heat and Power Systems
Question
Answer
Is the installation of a mCHP in a house
classified as permitted development under the
Town and Country Planning Regulations?
Yes providing: Click here to reveal
Flues on the rear or side elevation of the house
project no more than one metre above the
highest part of the roof.
The house is not listed, not in a designated area
not in a conservation area or in a World Heritage
site
What effect does ‘on’ – ‘off’ cycling operation
have on a mCHP unit?
The operation isClick
inefficient
it is unlikely that
here toand
reveal
the unit will produce electricity.
What type of heat-demand is most suitable for
a mCHP system?
Click here to reveal
A high heat demand
How did you do?
Module 3: Co-generation Technologies
Micro-Combined Heat and Power Systems – Advantages and Disadvantages
Some example advantages and disadvantages are:
Advantages
Disadvantages
Domestic mCHP units are now similar in size to
a central heating boiler
The cost of domestic mCHP units do not
compare favourably to central heating boilers
Heat-led mCHP units produce free electricity
whilst generating heat
Heat-led mCHP units are not suitable for
property with low heat demand
Eligible for Feed-in Tariff payments (subject to
conditions)
Heat-led mCHP units have a limited electrical
generation capacity
Does not rely on building orientation or
weather conditions to generate renewable
electricity
Unlike other renewable electricity producing
technologies, mCHP is a low carbon rather
than zero carbon technology
Well Done! You have now completed the micro-combined heat and power systems
section.
Click on menu to return to the module menu.
Module 4: Water Conservation Technologies
Module 4: Water Conservation Technologies
Rainwater Harvesting Systems
Objectives
At the end of this section you will:
•
•
•
•
understand the fundamental working principles of a rainwater harvesting system
recognise the top level regulatory requirements that apply in relation to rainwater
harvesting system installation work
recognise the fundamental requirements of building location and building features
for the potential to install to a rainwater harvesting system to exist
recognise the typical advantages and disadvantages rainwater harvesting systems

Module 4: Water Conservation Technologies
Rainwater Harvesting Systems - Introduction
A rainwater harvesting system captures and stores
rainwater for permitted non-wholesome usage.
A rainwater harvesting system reduces mains water
usage.
Although not typically associated with being a low
carbon technology, rainwater harvesting systems
do reduce wholesome (mains) water consumption.
To become ‘wholesome’ water is treated by the
water supply company before it is supplied. Any
reduction in usage of wholesome water will also
lead to energy savings and a carbon emission
reduction through a reduction in treated water
consumption.
Module 4: Water Conservation Technologies
Rainwater Harvesting Systems – Permitted use of harvested rainwater
Harvested rainwater is classified as Class 5 Risk under the Water Supply
(Water Fittings) Regulations 1999.
If harvested rainwater is filtered, stored correctly and used frequently,
untreated harvested rainwater is suitable for use and is permitted for use
for the following purposes:
•
•
•
•
Supplying an clothes washing machine
Flushing WCs
Garden watering/irrigation
Car washing
Harvested rainwater is not suitable for use and is not permitted for use for
the following purposes:
•
•
•
•
Drinking water
Dishwashing (hand or machine)
Food preparation
Personal washing, showering bathing
Module 4: Water Conservation Technologies
Rainwater Harvesting System Layout and Key Components
(Indirect distribution with below ground tank)
Click on each number for a
brief overview
3
2
1
4
Please note that due
to the intended
purpose of this
learning tool, some
system components
are not shown. This is
not an installation
diagram.
Module 4: Water Conservation Technologies
Rainwater Harvesting System Components - Below Ground Storage Tank
The storage tank can be located above or
below ground providing the stored water is
protected from freezing, warming and
bacterial contamination.
Water enters the storage tank via the calmed
inlet. The calmed inlet minimises turbulence
and slows the flow of water into the tank
The harvested rainwater is then pumped away
to the outlet points using a submersible pump.
Where possible, the submersible pump is best
supplied via a floating extraction point to avoid
disturbance of any sediment at the bottom of
the tank.
Module 4: Water Conservation Technologies
Rainwater Harvesting System Components – Inlet filter
Before the harvested rainwater enters the
storage tank it must pass through an approved
type inlet filter.
The inlet filter can be located anywhere in the
collection pipework but must be accessible for
maintenance purposes.
Module 4: Water Conservation Technologies
Rainwater Harvesting System Components – Intermediate Storage Cistern
Harvested rainwater can be distributed directly
from the storage tank or distributed via an
intermediate storage cistern.
Where an intermediate storage cistern is
included the arrangement shown is used.
A key requirement is the inclusion a back-up
wholesome water supply. The back-up supply
can be from a mains water supply or a private
water supply.
Backflow of the stored rainwater into the backup water supply must be prevented. The
required backflow prevention arrangement is
a Type AA air gap.
Module 4: Water Conservation Technologies
Rainwater Harvesting System Components – Signage and Labelling
Appropriate signage and labelling must be
provided to minimise the risk of incorrect use
of harvested rainwater and/or the possibility
of cross-connections between wholesome
water systems and harvested rainwater
systems.
All harvested rainwater pipework systems must
be suitably marked to identify its use using
either approved type labels at stated maximum
intervals or using pipe that is marked during
the manufacturing process
Module 4: Water Conservation Technologies
Rainwater Harvesting System Layout (example direct distribution system with above ground tank)
Please note that due
to the intended
purpose of this
learning tool, some
system components
are not shown. This is
not an installation
diagram.
Module 4: Water Conservation Technologies
Rainwater Harvesting System Layout Options
We have looked at example system layouts for:
•
•
Below ground rainwater harvesting storage tank with indirect distribution
system via an intermediate system
Above ground rainwater harvesting storage tank with direct distribution
system
Other storage tank and distribution system arrangements include:
•
•
•
Below ground rainwater harvesting storage tank with direct distribution
system
Above ground rainwater harvesting storage tank with indirect distribution
system via an intermediate system
Above ground high-level storage tank (usually internal) with gravity
distribution to outlets.
Module 4: Water Conservation Technologies
Rainwater Harvesting Systems
Question
Answer
Is harvested rainwater suitable for use to supply
a bath or shower?
No
What is the purpose of a Type AA air gap
arrangement in a rainwater harvesting system?
To prevent backflow
of stored
rainwater into the
Click here
to reveal
wholesome water supply
Why is labelling and marking of rainwater
harvesting pipework and outlets important?
To minimise the
riskhere
of incorrect
Click
to revealuse of
harvested rainwater and/or the possibility of
cross-connections between wholesome water
systems and harvested rainwater systems.
Which component is a floated extraction
connected to?
Click
here to reveal
The submersible
pump
How did you do?
Click here to reveal
Module 4: Water Conservation Technologies
Rainwater Harvesting Systems
The installation of rainwater harvesting systems will require
compliance with a number of regulatory requirements including
health and safety, water regulations . A competent installation
contractor will have a detailed knowledge of these regulations and
will ensure compliance.
Within this section we consider two primary regulatory
requirements in relation to rainwater harvesting systems :
•
•
Building Regulations
Town and Country Planning Regulations
Note: The requirements stated in this section relate to England
and Wales only. The requirements for Scotland and Northern
Ireland may differ.
Module 4: Water Conservation Technologies
Rainwater Harvesting Systems – Regulatory Requirements
The Building Regulations (England and Wales) comprise of 14 parts.
Six of these parts may have relevance to rainwater harvesting systems installation.
Part
Topic
Relevance or possible relevance
A
Structure
Where rainwater Click
harvesting
system
here to
revealcomponents put
load on the structure and/or where excavations are
made near to the structure
B
Fire Safety
Where holes for pipes
etc. may
reduce the fire
Click here
to reveal
resistant integrity of the building structure
C
Site preparation and resistance to
moisture
Where holes for pipes
etc. may
reduce the moisture
Click here
to reveal
resistant integrity of the building structure
E
Resistance to the passage of
sound
Where holes for pipes
etc. may
reduce sound proof
Click here
to reveal
integrity of the building structure
G
Sanitation, hot water safety and
water efficiency
Water efficiency Click here to reveal
H
Drainage and Waste Disposal
Rainwater guttersClick
and here
rainwater
pipework connected
to reveal
to rainwater harvesting systems
P
Electrical safety in dwellings
The connection ofClick
rainwater
harvesting
here to
reveal system
electrical components
Module 4: Water Conservation Technologies
Rainwater Harvesting Systems – Regulatory Requirements
Town and Country Planning Regulations
Planning permission is not normally needed when installing a rainwater harvesting system in a
house if the finished installation does not alter the outside appearance of the property. Where
above ground rainwater harvesting storage tanks are to be included, planning permission may
be required.
If the building is listed or in a designated area it is advisable to check with the local planning
authority before installing a rainwater harvesting system even if the building has permitted
development rights . Consent is also likely to be needed for internal alterations to listed
buildings.
The local planning authority should also be consulted if the property is In a conservation area or
in a World Heritage site.
If the project requires an outside building to house the rainwater harvesting
storage tanks same rules apply to that building as for other extensions
and garden outbuildings.
Module 3: Co-generation Technologies
Rainwater Harvesting Systems - Building location and feature requirements
For the potential to install to a rainwater harvesting system to exist, as a
minimum some or all of the following building and location factors will
need to be considered:
•
A suitable location and space for a storage tank of a suitable size to
meet the demand.
•
A suitable location for rainwater harvesting system storage tank(s)
to minimize the potential for freezing, warming and algal blooms
•
For retrofit installations access for excavation machinery may also
need to be considered.
•
A suitable supply (yield) of rainwater in relation to the demand on
the system. Rainwater harvesting systems are not suitable for areas
with a low rainfall intensity or suitable for buildings with a small
rainwater catchment area.
•
The availability of a wholesome back-up water supply
Module 4: Water Conservation Technologies
Rainwater Harvesting Systems
Question
Answer
Why is Part A of the Building Regulations relevant
to the installation of a rainwater harvesting system?
Because the load
imposed
system components
Click
here tobyreveal
such as storage tanks and cisterns may affect the
structure of the building. Also, any excavation
work may have an effect on the structural
stability of the building.
Is planning permission normally required for a
rainwater harvesting system installation?
Click here
to reveal
Not normally unless
the storage
tank is above
ground or unless the building is listed or located
is a conservation area or similar type of area.
Is a rainwater harvesting system suitable for a
building that is located in an area with low rainfall
intensity?
No
How did you do?
Click here to reveal
Module 4: Water Conservation Technologies
Rainwater Harvesting Systems – Advantages and Disadvantages
Some example advantages and disadvantages are:
Advantages
Disadvantages
Conserves wholesome water
Payback periods can be long.
Indirectly reduces energy consumption and
reduces carbon emissions
Not always straightforward to install to
existing building
A wide range of system options exist
There is a risk of contamination or crossconnection
Rainwater is free so for buildings where a
water meter is fitted the annual cost of water
will reduce
Only certain types of outlet and appliance can
be supplied using harvested rainwater
Well Done! You have now completed the rainwater harvesting systems section.
Click on the forward arrow to return to the water conservation technologies menu page
Module 4: Water Conservation Technologies
Greywater Re-use Systems
Objectives
At the end of this section you will:
•
•
•
•
understand the fundamental working principles of a greywater re-use system
recognise the top level regulatory requirements that apply in relation to greywater
re-use system installation work
recognise the fundamental requirements of building location and building features
for the potential to install to a greywater re-use system to exist
recognise the typical advantages and disadvantages for greywater re-use systems

Module 4: Water Conservation Technologies
Greywater Re-use Systems - Introduction
A greywater re-use system captures and stores ‘grey’
waste water that is discharged from washbasins,
baths, showers washing machines and kitchen sinks
for permitted non-wholesome usage
A greywater re-use reduces mains water usage.
As with rainwater harvesting systems, greywater reuse systems are not typically associated with being
a low carbon technology, greywater re-use systems
do reduce wholesome (mains) water consumption.
Any reduction in usage of wholesome water will also
lead to energy savings and a carbon emission
reduction through a reduction in treated water
consumption.
Module 4: Water Conservation Technologies
Greywater Re-use Systems – Permitted use of reclaimed greywater
Greywater is classified as Class 5 Risk under the Water Supply (Water Fittings)
Regulations 1999.
If greywater is filtered, stored correctly and used frequently and where
necessary treated, greywater is suitable for use and is permitted for use for
the following purposes:
•
•
•
•
Flushing WCs
Garden watering/irrigation
Car washing
Supplying an clothes washing machine (if appropriately treated)
Greywater is not suitable for use and is not permitted for use for the
following purposes:
•
•
•
•
Drinking water
Dishwashing (hand or machine)
Food preparation
Personal washing, showering bathing
Module 4: Water Conservation Technologies
Greywater Re-use Systems – Types of system
System Type
Description
Direct re-use system
A system that collects greywater from appliances and delivers it directly
to the points of use with no treatment and minimal, or no storage.
Short retention
system
A system that includes a basic filtration or treatment technique such as
surface skimming and allow for natural particle settlement.
Basic
physical/chemical
system
A system that filter s greywater prior to storage and uses chemical
disinfectants such as chlorine or bromine to stop bacterial growth during
storage
Biological system
A system that introduces an agent, such as oxygen, into the stored
greywater to allow bacteria to digest any unwater organic mater. Pumps
or plants can be used to aerate the stored water.
Bio-mechanical
system
A system that combines both physical and biological treatment.
Hybrid system
A combination of any of the above systems or a combiner rainwater
harvesting and greywater re-use system.
Module 4: Water Conservation Technologies
Greywater Re-use Systems – Storage, Treatment and Use Considerations
Greywater from showers, baths and washbasins will often be contaminated with human
intestinal bacteria and viruses as well as organic debris such as skin particles and hair.
Greywater will also contain residues of soaps, detergents and other cosmetic products; these
often contain nutrients that help bacteria develop. This combination of bacteria, organic material
and nutrients provides ideal conditions for bacteria to grow. The relatively high temperature of
greywater can also encourage the growth of bacteria further.
For these reasons untreated greywater should never be stored for more than a few hours.
If greywater is to be used for irrigation, it should be directly applied to soil and not through a
sprinkler or method that would allow contact with above ground portions of plants.
Greywater should not be used to water crops, which are eaten uncooked. It is recommended
that greywater should not be applied to seedlings or young plants.
Module 4: Water Conservation Technologies
Example Greywater System Layout and Key Components
Please note that due
to the intended
purpose of this
learning tool, some
system components
are not shown. This is
not an installation
diagram.
Module 4: Water Conservation Technologies
Greywater Re-use System Layout Options
We have just looked at an example layout for a below ground greywater re-use
storage tank with indirect distribution system via an intermediate storage cistern
system
A wide range of other system layout options exist including a number of options for
an internal greywater storage tank and treatment unit. The internal units come in a
variety of shapes and sizes and offer a lot of flexibility in system design.
As with rainwater harvesting systems, all greywater re-use system supply points and
pipework must be marked and labelled to minimise the risk of incorrect use of
reclaimed greywater and/or the possibility of cross-connections between wholesome
water systems and greywater re-use systems.
Module 4: Water Conservation Technologies
Greywater Re-use Systems
Question
Answer
Is reclaimed greywater suitable for use to supply
a clothes washing machine?
Yes if it is appropriately
before use.
Click heretreated
to reveal
(appropriate treatment is likely to be a
combination of membrane filtration, anaerobic
bacteria and ultra-violet disinfection)
What is a direct reuse greywater system ?
A system that collects
greywater
Click here
to revealfrom appliances
and delivers it directly to the points of use with
no treatment and minimal, or no storage.
Is reclaimed greywater suitable for use to water
vegetables that will be eaten uncooked?
No, this type ofClick
use is
nottorecommended
here
reveal
How did you do?
Module 4: Water Conservation Technologies
Greywater Re-use Systems
The installation of greywater re-use systems will require
compliance with a number of regulatory requirements including
health and safety, water regulations . A competent installation
contractor will have a detailed knowledge of these regulations and
will ensure compliance.
Within this section we consider two primary regulatory
requirements in relation to greywater re-use systems :
•
•
Building Regulations
Town and Country Planning Regulations
Note: The requirements stated in this section relate to England
and Wales only. The requirements for Scotland and Northern
Ireland may differ.
Module 4: Water Conservation Technologies
Greywater Re-use Systems – Regulatory Requirements
The Building Regulations (England and Wales) comprise of 14 parts.
Six of these parts may have relevance to greywater re-use systems installation.
Part
Topic
Relevance or possible relevance
A
Structure
Where greywaterClick
re-use
system
components put
here
to reveal
load on the structure and/or where excavations are
made near to the structure
B
Fire Safety
Where holes for pipes
etc. may
reduce the fire
Click here
to reveal
resistant integrity of the building structure
C
Site preparation and resistance to
moisture
Where holes for pipes
etc. may
reduce the moisture
Click here
to reveal
resistant integrity of the building structure
E
Resistance to the passage of
sound
Where holes for pipes
etc. may
reduce sound proof
Click here
to reveal
integrity of the building structure
G
Sanitation, hot water safety and
water efficiency
Water efficiency Click here to reveal
H
Drainage and Waste Disposal
Sanitary pipework
connected
greywater re-use
Click
here toto
reveal
systems
P
Electrical safety in dwellings
The connection ofClick
greywater
here tore-use
revealsystem electrical
components
Module 4: Water Conservation Technologies
Greywater Re-use Systems – Regulatory Requirements
Town and Country Planning Regulations
Planning permission is not normally needed when installing a greywater re-use system in a
house if the finished installation does not alter the outside appearance of the property. Where
above ground greywater re-use storage tanks are to be included, planning permission may be
required.
If the building is listed or in a designated area it is advisable to check with the local planning
authority before installing a greywater re-use system even if the building has permitted
development rights . Consent is also likely to be needed for internal alterations to listed
buildings.
The local planning authority should also be consulted if the property is In a conservation area or
in a World Heritage site.
If the project requires an outside building to house the greywater re-use
storage tanks same rules apply to that building as for other extensions
and garden outbuildings.
Module 4: Water Conservation Technologies
Greywater Re-use Systems - Building location and feature requirements
For the potential to install to a greywater re-use system to exist, as a
minimum some or all of the following building and location factors will
need to be considered:
•
A suitable location and space for a storage tank of a suitable size to
meet the demand.
•
A suitable location for greywater system storage tank(s) to minimize
the potential for freezing, warming and algal blooms
•
For retrofit installations access for excavation machinery may also
need to be considered.
•
A suitable supply (yield) of greywater in relation to the demand on
the system. Greywater re-use systems are not suitable for buildings
with a low volume of greywater discharge.
•
The availability of a wholesome back-up water supply
Module 4: Water Conservation Technologies
Greywater Re-use Systems
Question
Answer
Why is Part H of the Building Regulations relevant
to the installation of a greywater re-use system?
hereRegulations
to reveal states the
This part of the Click
Building
requirements relating to the design, installation
and testing of sanitary pipework connected to
greywater re-use systems.
Is planning permission normally required for a
greywater re-use system installation?
Not normally unless
tank is above
Click the
herestorage
to reveal
ground or unless the building is listed or located
is a conservation area or similar type of area.
Is a greywater re-use system likely to be suitable for
a property with two occupants who prefer to take
sort showers instead of baths?
Not typically because
thetovolume
Click here
reveal (yield) of
available greywater is likely to be insufficient to
make the system viable. However, some smallscale greywater systems may be suitable.
How did you do?
Module 4: Water Conservation Technologies
Greywater Re-use Systems – Advantages and Disadvantages
Some example advantages and disadvantages are:
Advantages
Disadvantages
Conserves wholesome water
Payback periods can be long.
Indirectly reduces energy consumption and
reduces carbon emissions
Not always straightforward to install to
existing building
A wide range of system options exist
There is a risk of contamination or crossconnection
Greywater is free so for buildings where a
water meter is fitted the annual cost of water
will reduce
Only certain types of outlet and appliance can
be supplied using reclaimed greywater
Well Done! You have now completed the greywater re-use systems section.
Click on the forward arrow to finish
Environmental Technology System Awareness
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‘Environmental Technology Systems Awareness’ learning tool.
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