CA Group Renewables Guide
www.cagroup.ltd.uk/renewables
An Introduction to Renewables
Renewable technologies are something that every building owner, developer and
tenant needs to consider. Renewables assist in compliance with UK Government
legislation, impact EPC ratings and reduce CO2 emissions resulting from the
operation of the building which will ultimately improve profit margins.
What are Renewables?
Renewables provide “a source of
energy that is not depleted by use,
such as water, wind, or solar power.”
Renewable energy is anything that
can be used to generate heat or
electricity without the need for
unsustainable fuels, such as gas
or coal, and which does not make
a net contribution of CO2 to the
atmosphere. This includes wind
power, tidal, solar and geothermal
energy and to some extent biomass.
Why use Renewables?
Building design has changed
dramatically in recent years and
sustainability is now a key factor
which needs to be incorporated.
Carbon neutral building materials
greatly improved thermal
performance. This change in attitude
is a result of many factors including
client aspirations, government
policy and public pressure. The end
result is companies such as the CA
Group are consistently pushing the
boundaries to achieve the most
sustainable building envelope
for their clients, for example by
offering CarbonNeutral buildings
and airtightness as low as 1.03m2/
m3/hr/m2 @ 50Pa. It cannot,
however, stop there we need to
continually improve and the UK
Government is leading the charge
with some challenging expectations
being placed on the market so
that renewable technologies
will feature very heavily.
Governments worldwide are
committed to reduce their carbon
emissions by supporting the Kyoto
Protocol. The Kyoto Protocol treaty,
which came into force in February
2005, is dedicated to fighting
global warming. Under the Kyoto
Protocol the UK Government has
committed to reduce the emissions
of four greenhouse gases; carbon
dioxide, methane, nitrous oxide
and sulphur hexafluoride. Over
50% of the UK’s overall energy
consumption and carbon emissions
is generated from the operation
of existing building stock and
accordingly the design of new
buildings is subject to increasing
pressure to reduce emissions with
the latest amendments to Approved
Document L 2010: Conservation of
Fuel and Power (Part L) imposing an
aggregate 25% improvement over
the 2006
building
regulations.
This in itself is
challenging,
but the UK
Government
is now also
placing a
significant
emphasis on
renewable
energy
to help
reduce a new building
carbon footprint further.
Although Part L gives no specific
guidance on low and zero carbon
technologies (LZCs) it does state
that the designer should “consider
making the building easily adaptable
by facilitating the integration of
additional LZC technologies”.
In addition to this the UK
Government has signed up to the
EU Renewable Energy Directive
under which it must meet legally
binding targets to produce 15%
of all its energy requirements per
annum from renewable sources
by 2020. As of 2008 the figure
achieved was approximately 2.25%,
clearly, therefore, a near seven-fold
increase is required in just over 10
years to achieve the target. This is
a truly staggering requirement. In
terms of electricity production this
is equivalent to the UK generating
around 35% of all its electricity from
renewable sources by 2020. We
are a long way off this target only
producing 6.6% of our electricity
from renewable sources.
To date the deployment of smallscale renewable technologies has
been limited due to a number
of factors including, but not
limited to, high capital costs, long
payback periods and difficulties
in obtaining planning consent.
While it has been relatively easy
to obtain planning consent for
technologies such as Solar PV
(Photovoltaics), the high capital
cost and low revenue stream has
seen much longer payback periods,
in some cases exceeding the 25 year
economic lifespan of the equipment.
To address some of the limiting
factors impacting small-scale
renewable technologies and
to encourage rapid and mass
deployment within the market,
Solar Radiation
Electricity either sent back to the
grid or utilised by the building
Photovoltaic
cells convert
solar radiation
into electricity
“Consider making the building easily adaptable by
facilitating the integration of additional LZC technologies.”
Approved Document L 2010: Conservation of fuel and power (Part L)
the UK Government introduced
a gross Feed-In Tariff (FIT)
scheme for renewable energy
generation within the UK.
The FIT scheme commenced on 1st
April 2010 and provides renewable
electricity generators with a
guaranteed fixed price for every
kilowatt hour (kWh) of renewable
electricity produced. All FIT
payments are index linked to UK RPI
and for Solar PV payments are made
for a period of 25 years. In addition to
the significant economic benefits of
the FIT scheme, generators are also
able to reduce their own electricity
bills by consuming whatever
electricity is produced on site for free
and exporting any unused electricity
back to the National Grid thereby
generating additional revenue.
The FIT scheme and associated
reduction in energy costs presents
generators with a highly attractive
economic incentive to invest in
small-scale renewable technologies,
particularly for Solar PV which is
subject to the highest FIT payments,
by dramatically reducing payback
periods and enhancing bottom
line profits from the outset.
A similar scheme is set to be
introduced in the UK in June 2011
for renewable heat production.
The Renewable Heat Incentive (RHI)
will provide payment for generating
heat from renewable sources and
will be set by UK Government
depending upon the size and type
Large scale Solar PV installations are
common place through out Europe
of technology used. The RHI will be
administered by the official regulator
Ofgem but unlike the FIT scheme, it
will be paid directly by the Treasury
and not the energy suppliers as there
is no ‘National Grid’ in which excess
heat can be exported back into.
These pressures posed by UK
Government, along with a change
in attitude in the market, has meant
that solar ready buildings are now
in demand. At CA Group we ensure
all our systems are solar ready, so a
variety of systems can be installed
at any point in the buildings life.
This document will explain the
renewable technologies available.
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Solar Photovoltaics (Solar PV)
All Solar PV technology works on
a similar principal. Thin layers of
silicon are doped with positive
and negative elements that form
a junction where electrons flow
when excited by solar radiation.
Silicon is a crystalline or amorphous
element with semi-conductor
properties allowing electrons to
freely flow across the junction
thereby generating electrical power.
Solar cells can be manufactured
from both types of solid-state
silicon resulting in two very
different types of Solar PV panels.
Solar Radiation
N-type
Silicon
P-type
Silicon
Photovoltaics: Monocrystalline
Monocrystalline cell wafers are
sliced from a single cylindrical silicon
crystal that has been grown under
carefully controlled conditions.
The end result is that all the silicon
crystals are aligned in one direction
(hence the name ‘mono’) making
this the most complex and costly
of all solar cells to produce. They
are also the most efficient cells
currently available in the market
and monocrystalline Solar PV
panels are ideally suited for use
where space is restricted and
weight restrictions do not apply.
Photovoltaics: Polycrystalline
Polycrystalline cell wafers are
made up of multiple silicon
crystals formed by pouring
molten silicon into a mould that
is allowed to cool then sliced into
wafers. The process is significantly
cheaper than monocrystalline
cell production but efficiency of
the cells and resulting Solar PV
panels is lower. Polycrystalline
Solar PV panels are ideally used
where space is not restricted and
weight restrictions don’t apply.
Photovoltaics: Amorphous Thin Film
Thin film production methods
are very different from crystalline
cell wafer production. Instead of
growing crystals or pouring moulds,
amorphous silicon is deposited in
a very thin layer on to a backing
substrate. This significantly
reduces the amount of silicon
required to construct the cells and
therefore reduces the cost of thin
film technology when compared
to crystalline alternatives. This
cost saving does come at a price
because the efficiency of thin film
is lower than that of the crystalline
alternatives. To combat this some
manufacturers use several layers
of amorphous silicon laid on top of
one another, with each silicon layer
developed in slightly different ways
to respond to different wavelengths
of light to
improve
the
efficiency.
Thin film is ideally suited when space
is not an issue and flexible thin film is
the product of choice where weight
restrictions limit the deployment
of crystalline Solar PV panels.
The Benefits of Photovoltaics
Solar PV in Operation
Regardless of the type of Solar PV
technology, all Solar PV arrays work
in the same way. Once installed, the
Solar PV panels are connected in
strings that are fed into an inverter
to convert the direct current (DC)
electricity into alternating current
(AC). AC is the standard form of
grid-supplied electricity. All inverters
work on ‘positive pressure’ which
in simple terms means that any
electricity generated by the Solar
PV array will be ‘pushed’ to meet
the existing electrical demand of
the building before it is exported
to the National Grid (if at all).
If the electrical demand of the
building is higher than the Solar
PV array can supply, electricity
is imported from the National
Grid. This is a seamless process.
The German market is the largest
and maturest market in the world
today and the empirical evidence
from Solar PV arrays installed
in Germany has shown without
question that the technology
produces electricity in line with
long term forecast expectations.
UK Light Conditions
Solar PV generates electricity from
any light condition (including cloudy
days) and does not require direct
sunlight in order to be effective. It
is a common and untrue myth that
the UK does not have a sufficient
solar resource to support Solar PV.
Amorphous thin film technology
is particularly well suited to the UK
climate because it works better in
diffuse light conditions (varying
wavelengths of light). The map
below demonstrates that south of
the M62 in the UK is very similar
in terms of the irradiation levels
experienced in Southern Germany.
The map below shows
the distribution of global
irradiation in the UK per year
The gross amount of AC electricity
generated is measured and recorded
on a generation meter while any
electricity exported to the National
Grid is recorded on a separate export
meter (this applies to all systems
greater than 30kWp in size). The
difference between the generation
and export meter readings is the
generation used on site. Solar PV
arrays are classified in size according
to maximum peak installed capacity
and measured in terms of kilowatt
peak (kWp). A typical commercial
Solar PV array comprising of 1,000
polycrystalline Solar PV panels
should have a peak installed capacity
of around 200kWp (depending on
the size and type of panel used).
Proven Technology
Solar PV technology is well
established, having been developed
steadily since the late 1950s and
the current technology is the
most efficient ever produced.
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Degradation
Over time all forms of silicon
naturally degrade as a result of the
photovoltaic effect and therefore
the performance of each Solar
PV panel decreases slightly each
year. The expected degradation
is in the region of 0.5% annually
for crystalline technology. This is
slightly improved for amorphous
thin film technology that degrades
in the region of 0.4% annually.
Product Warranties
Solar PV panels and inverters
normally come with a five year
manufacturers product warranty.
Due to the degradation effect, Solar
PV panels also come with a 90%
output performance guarantee for
the first 10 years followed by an
80% output performance guarantee
of the remaining 15 years.
Panel Cleaning
Solar PV panels have a useful life
in excess of 25 years. Scheduled
cleaning of the panels is required
from time to time to ensure
optimised system performance.
The exact timing of cleaning will be
dependent on monitored system
outputs. When the expected system
output falls below an agreed
level cleaning may be required.
Keeping Solar PVs clean enables
optimum performance
In the interim period Solar PV
panels will remain operational
with small amounts of dust and
dirt accumulated on the surface.
In any event all types of Solar PV
panels have some form of selfcleaning surface whether it is selfcleaning glass for crystalline panels
or a Teflon® coating for amorphous
flexible thin film that is designed to
aid run off in low pitch applications.
The cleaning process for crystalline
and thin film panels is essentially the
same although for products such
as amorphous thin film cleaning
and maintenance is made much
simpler by the fact that the panels
are fully walkable and virtually
unbreakable. If the amorphous cell
does break down the panel can be
easily unclipped from a CA TwinTherm® roof and replaced, without
causing any damage to the roof.
To ensure that any Solar PV array is
working to its maximum optimal
capacity for the longest period
of time, CA Group recommends
outsourcing the long-term operation
and maintenance of any Solar PV
asset to a specialist third party
service provider, such as ESCO NRG.
Inverters and Reliability
Inverters are the weakest link in any
Solar PV array. The right choice of
manufacturer along with scheduled
preventative maintenance are
important factors in enhancing
the performance of the invertors
as well as extending
their life. Using
reputable and well
established inverter
manufacturers such
as SMA and Fronius
is key to ensuring
optimal system yields.
Further, by scheduling
regular servicing of
inverters including
on-going replacement
of key components, the life of an
inverter can be extended beyond
20 years and it is rare that an
entire inverter would need to
be replaced. Scheduled inverter
maintenance should be included
in any O&M service provided.
Operations and
Maintenance (O&M)
A robust O&M package is a
fundamental requirement for
expected investment yields to
be realised over the lifetime of
any Solar PV asset. It is critical
to continually monitor system
outputs to ensure optimal system
performance. Generally speaking
O&M is prudent risk management
for any Solar PV asset.
There are two key metrics
that must be included in any
O&M package: (i) guaranteed
performance ratios (matched
to specific system performance
ratios); and (ii) guaranteed system
availability. In order for such
guarantees to be maintained,
O&M operators will provide 24
hour system monitoring, regular
inverter servicing, annual system
inspection as well as regular panel
cleaning in order to be effective.
In addition providers such as
ESCO NRG can also cover ongoing
management of Feed-In Tariff and
export agreements (including LEC
and REGO submissions with Ofgem),
cash flow management, maintaining
warranty schedules
and arranging
dedicated Solar
PV insurance. In
short there is a
lot to manage for
commercial scale
Solar PV assets.
It’s not a choice between our
environment and our economy;
it’s a choice between prosperity
and decline”
President Barack Obama
Life Cycle Considerations
When Solar PV panels come to
the end of their useful economic
life, they can be recycled through
schemes such as PV CYCLE. The
scheme, founded in 2007, recycles
Solar PV panels that have come to
the end of their life and recovers
materials that can be reused in
either new Solar PV panels or other
new products. This is a rapidly
expanding and competitive market
and many new market entrants
are joining this growing industry.
Quality Considerations
It is important to ensure that the
most reliable Solar PV panels
are used. The reliability of the
technology used, the design
and installation of each system,
ongoing monitoring, maintenance
and management is all geared
toward generating the highest
possible electrical output from
each Solar PV array and this is
the key to ensuring the highest
possible investment return.
Planning
Generally installing PV panels on
commercial properties falls outside
permitted development rights
and therefore planning consent
is required. Planners to date have
been very receptive to commercial
roof top installations and often
consent is provided without the
need for a full planning application.
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Design Considerations
Solar PV panels can be installed in
plane on pitched roofs, on raised
brackets on pitched roofs, on
raised stands on flat roofs, or on
ground mounted stands. There
really are endless possibilities
to mounting Solar PV panels.
It is vitally important that the correct
mounting structure for the roof
system and the type of Solar PV
panel. Thin film technology works
better on low pitch mountings,
such as in plane with an existing
low pitch roof, while crystalline
panels are ideally suited for raised
mounting structures. In all instances
care must be taken to ensure proper
ventilation of the Solar PV panels
and expert advice should be sought
before any work is carried out on
an existing or new roof structure.
Important checks before embarking on a Solar PV Scheme
• Always check with a structural engineer that the
proposed weight of the Solar PV installation will not
exceed the design parameters of the steel frame.
• Check with the roof system and external
weather skin providers that their system
guarantee will not be affected.
• In relation to portal frames and curved roofs install
equal amounts of PV panels on both slopes to
ensure the loads on the frame are in balance.
• When clamping the Solar PV panels to the roof avoid
compressing any insulation as this could cause
premature failure of the roof and water ingress.
• Before anybody begins work on a roof to install
a Solar PV system ensure that the roof is a nonfragile assembly in accordance with HSE (Health
& Safety Executive) guidance and that those
working on the roof are properly protected from
falling through or off the roof at all times.
• Avoid penetrating the roof from outside to
in, as it increases the risk of roof leaks.
• Allow safe walkways around rooflights, along
the roof from gable to gable and up and over
the roof ridge to eaves to ensure safe access
on and around the roof itself without the
need to stand on any questionable area.
• To ensure that the Solar PV panels do not overheat air
should flow above and below the panels so that they
do not exceed the designed operating temperature.
• If a separate mounting frame is to be installed
ensure that it is fixed to the frame and
designed to take account of wind loadings.
• Where in plane glass encased Solar PV panels are
used, beware of the risks of damage due to foot
traffic and ensure that only trained professionals
are given access to the roof during both installation
and over the life of the Solar PV system.
Solar Air Heating
Solar Air Heating systems capture the energy emitted from
the sun, to provide a source of renewable heat.
Solar Air Heating systems capture
the energy emitted from the sun, to
provide a source of renewable heat.
In order to fully understand how
solar air heating systems work, it
is important to understand the
basic principle as to how the sun’s
energy reaches the earth’s surface.
Bright, clear, cold winter days are the
optimal climatic conditions for the
use of any solar air heating system.
Under these conditions a solar air
collector is able to provide maximum
output when it is needed the most.
Solar radiation arrives at the solar
collector in three ways: as direct,
diffuse and reflected radiation.
Direct radiation consists of parallel
rays of energy that arrive straight
from the sun and it is the cause
of shadows on clear days. Diffuse
sky radiation is created from direct
radiation that has been scattered
by clouds and dust particles in the
atmosphere, creating non parallel
rays of energy and reflected
radiation is energy that is received
from adjacent surfaces such as
buildings and the ground etc.
An almost constant amount of
solar radiation (1,300 - 1400W/
m²) is measurable at the exterior
of the earth’s atmosphere, but a
large proportion of this energy
is lost within the atmosphere via
absorption and reflection as it
travels towards the earth’s surface.
The purity of the atmosphere,
vapour, dust and smoke content
all have an effect on radiation,
along with the seasonal angle
of the sun. Clouds and particles
in the atmosphere not only
reflect and absorb solar energy,
but also scatter it in many
directions (diffuse radiation).
Diffuse radiation can account
for up to 50% of the total annual
solar irradiance falling on a south
facing vertical wall, whereas
reflected radiation from adjacent
surfaces amounts to circa 20% of
the direct and diffuse radiation.
The energy performance and
efficiency of any solar air heating
system is influenced by many
factors including; orientation
(Azimuth), area, slope and collector
type, along with its usage.
Early systems used conventional
flat plate solar collectors and were
based on a technology that had
initially been developed to heat
re-circulated, internal building air.
They relied on the heat transferring
through the material. As a result
they were very ineffective.
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Solar Air Heating
There are two main types of solar
air collectors in use today, termed
either glazed or unglazed:
Glazed Solar Collectors are primarily
designed for space heating
applications and operate by recirculating internal building air
through the collector where it is
re-heated before being delivered
back into the building. These types
of solar air heating systems require
at least two penetrations into
the building and only provide a
useful benefit when the air in the
solar collector is warmer than the
internal air temperature. Glazed
solar air heating systems are
mainly suited to smaller residential
applications and are ineffective
as the glazing has been found
to reflect up to 15% of the solar
energy back into the atmosphere.
Unglazed Solar Collectors are
primarily used to heat ambient air
(fresh air) and not re-circulated
internal building air and generally
only require one penetration
into the building. These types of
collectors can be used in a wide
range of applications ranging
from standard space heating, to
process heat and agricultural crop
drying and ventilation. As a result
of heating ambient air, this allows
solar energy to be utilised whenever
the air temperature in the collector
is above the ambient temperature
and not room temperature. This
can provide twice the solar energy
gain over space heating designs.
There are two types of unglazed
panels, Non-Perforated (Back
–Pass) Solar Collectors and
Transpired Solar Collectors (TSC’s)
- (Perforated Plate Collectors).
Non-Perforated (BackPass) Solar Collectors
The Non-Perforated (Back-Pass)
Solar Collector is one of the earliest
forms of solar air heating that was
predominantly utilised during the
1980’s throughout Canada and
North America. It works by drawing
ambient air into the system at the
base of the collector, which is then
passed vertically across the back
(back-pass) of a sun warmed, unperforated metal collector, before
the heated air is delivered into the
building. The lack of perforations
within the collector means that
the system has to rely on any solar
heat to be conducted through the
collector material before it can be
transferred to the air stream, with
only air in close contact to the
collector absorbing any useful heat.
As a result, the Non-Perforated
(Back Pass) Solar Collector cannot
benefit from the thermal boundary
layer or air that is generated on
the external face of the collector
which has been proven to contain
up to 62% of the total available
energy falling on the system and
as such total system efficiencies
range between 15-25%. (Efficiency
being defined as conversion of
solar gain into usable energy.)
Field experience has shown that
the further the incoming air has to
travel across the collector, the less
efficient the solar collector becomes
and if increased volumes of air need
to be heated then the only way to
accommodate this is to increase
the depth of the solar collector.
This impacts further on system
efficiency as it results in less air in
contact with the collector, further
reducing the rate of heat transfer.
Glazed Solar Collector
Non-perforated (Back-Pass)
Unglazed Solar Collector
Transpired Solar Collectors
should be installed on the most
southerly facing elevation in order
to maximise solar exposure.
Improve your EPC rating
TSC’s have now been incorporated
into the SBEM (Simplified Building
Energy Model) and can be used to
greatly improve a buildings thermal
performance and EPC (Energy
Performance Certificate) rating.
Transpired Solar Collectors
(Perforated Plate Collectors)
Transpired Solar Collectors (TSC’s)
have the highest known operating
efficiency of any solar collector,
with efficiencies as high as 80%.
The system consists of a pre-coated,
steel collector with thousands
of tiny perforations specifically
spaced across its full face. Installed
as an additional skin to a building’s
southerly elevation the system
is fully building integrated and is
engineered to suit the requirements
of each individual application. As
solar radiation is absorbed by the
collector, solar heat conducts to the
boundary layer
Uniformly
of air which lines
spaced
the outer surface
perforations
of the panel. This
heated boundary
layer of air is then
drawn through
the perforations,
into an air cavity
behind, before the heat can escape
by convection, virtually eliminating
heat loss from the surface of the
collector – capturing up to 400%
more solar gain than traditional
Non-Perforated (Back-Pass) Solar
Collectors .This allows the system to
achieve financial payback in as low
as 3 years on new build applications
and within 7 years on retrofit.
The solar heated air can be fed
directly into the building as heated
ventilation, ducted into a HVAC
unit where it can be used as a
pre-heater for the building’s main
heating system, or used as process
heat, for example in crop drying.
On a typical bright, clear day
(irrelevant of outside temperature)
the CA SolarWall® system can be
used to heat fresh, outside air by as
much as 25-30°C
above its ambient
temperature,
with each square
meter of collector
Heated
generating up to
boundary
layer of air 500W (0.5kW) of
thermal energy.
Suitability
TSC’s can be installed on almost
any type of building, new build
or refurbishment projects and
SBEM was developed by BRE
(Building Research Establishment)
for the department for Communities
and Local Government (CLG). The
software determines CO2 emission
rates for new buildings and produces
an EPC to allow the building to
comply with Part L regulations.
An EPC includes information
such as; carbon emissions,
energy consumption and
the asset rating (A-G).
The latest version of SBEM is
capable of directly analysing the
improvement in building energy
performance and allows architects
and consulting engineers to witness
firsthand the significant benefits
that can be provided by TSC’s.
Low and zero carbon technologies
can boost an asset rating.
The higher the asset rating on
the EPC, the more likely the
building will holds its value for
longer and rental incomes will
come under less pressure.
The building
will also
be more
attractive to
tenants due
to its lower
energy cost.
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Transpired Solar Collectors
The fresh, solar heated air is drawn into
the building via a fan / heating unit and
delivered via an air distribution system
SolarWall® collector
absorbs the sun’s
energy, heating the
fine layer of boundary
air that lines it’s
external surface
The air space inside the SolarWall® is
under negative pressure, drawing the
warm air upwards
SolarWall® panels
SolarWall® Transpired Solar Collector
Originally developed by Canadian
company Conserval Engineering
Inc. during the late 1980’s, the
Transpired Solar Collector (Branded
SolarWall®) is a proven renewable
energy technology that has been
validated through extensive
independent testing and third party
monitoring on a global scale.
”Utilised in over 34 countries
across 6 continents, SolarWall® is
an engineered to order system
with the highest known efficiency
of any active solar technology in
the world” – Dr. Chuck Keutcher
U.S. National Renewable
Energy Laboratory (NREL).
During its development, the
SolarWall® technology was
vigorously tested at the world’s
largest solar test facility – Bodycote’s
National Solar Test Facility in Toronto
– and has since been rated in the
top 2% of energy inventions by
the U.S. Department of Energy.
The SolarWall® technology is
exclusively available in the UK
from CA Building Products and as
such has also been independently
tested and verified within the
UK climate by the following
respected bodies, BSRIA, DSA
Engineering and Battle McCarthy;
BSRIA
The 410m² SolarWall® system
at CA Group’s site in Evenwood,
Co. Durham was monitored over
a 15 month period by BSRIA, a
non-profit, independent research
and consultancy organisation.
They analysed gas usage for CA’s
production facility both before
(based in the previous 7 years)
and after the installation of the
SolarWall® and concluded that
it led to a ‘substantial’ reduction
in gas consumption of 50%
once degree day correlated.
This equates to annual energy
and CO2 savings of 303,543kWh
and 58.9tCO2 respectively.
The RHI will be administered by the
official regulator Ofgem but unlike
the Feed-In Tariff scheme, it will
be paid directly by the treasury.
E
East
Wall
Guarantees
CA Group offer
up to a 25 year
guarantee, with
all SolarWall®
installations.
S
st
Both new build and refurbishment
projects can take advantage of
the CO2 and energy savings that
N
Ea
hut
So all
W
New build or refurbishment
Ideal orientation for SolarWall® is up
to 20° either side of South which will
give 96-100% solar
gain. Anything
within a West to
East orientation
is acceptable
and will achieve
West
Wall W
a minimum of
60% solar gain.
By introducing fresh air into the
building the SolarWall® system
can help eliminate the problems
associated with modern airtight
buildings and more than meets
ventilation requirements.
hW
W est
al
l
The RHI will provide a financial
incentive for those who generate
heat from renewable sources.
The level of the incentive will
be set in relation to the size and
type of technology used.
Orientation
Ventilation
ut
To encourage the generation of
renewable heat and to help meet
energy generation and carbon
emission reduction targets,
the UK Government is set to
introduce the Renewable Heat
Incentive (RHI) in June 2011.
SolarWall® can provide. The panel
can blend in with the rest of
the building or can stand out to
make a statement and enhance
the buildings aesthetics.
So
Renewable Heat Incentive (RHI)
South
Wall
900
900
DSA Engineering
DSA Engineering were asked
by a developer to prepare a
report comparing various types
of renewable technologies. The
study focused on a potential site in
Swavesey, South Cambridgeshire.
They reviewed 5 technologies;
photovoltaic’s, solar thermal,
ground source heat pumps,
wind turbines and SolarWall®.
SolarWall® was found to be
the only system that would be
economically viable whilst
satisfying the 10% onsite renewable
target for the development.
Battle McCarthy
The consultants at Battle McCarthy
carried out an analytical study on
a typical SolarWall® installation.
They concluded that for a building
internally heated to 15°C and
above the SolarWall® would make
a significant contribution to both
the heating (50-70%) and overall
energy consumption (+20%)
of the building and therefore
provide compliance with the
requirements of the ‘Merton Rule’.
(Please visit our website, to
download the full reports.)
13
www.cagroup.ltd.uk/renewables
Transpired Solar Collectors
Warmed air from the surface of the
collectors is drawn in to the heating system
for distribution
SolarDuct®
SolarDuct® is a modular rooftop
solar air heating system based on
the highly efficient, award winning
SolarWall® Transpired Solar Collector.
The system operates in the same
manner as the standard SolarWall®
collector, however the SolarDuct®
system has been specifically
developed for use on rooftop
applications, when it may not be
feasible or even suitable to utilise the
traditional wall mounted system.
As with the SolarWall® system, the
SolarDuct® technology harnesses the
suns energy to heat the ventilation
air supply before it enters the main
air handling plant. Manufactured
in a standard module size, the
number and length of SolarDuct®
units required for each application
are specifically calculated based on
the quantity of fresh air that is to be
heated and the energy / temperature
requirements of the building.
SolarWall® is a registered trademark of Conserval Engineering
Depending
upon available
roof space, the
SolarDuct®
units can be
orientated for
maximum system
performance
and are not
limited to the fixed orientation
of the building elevations. The
SolarDuct® system is the perfect
SolarWall® system alternative for
applications where the air handling
plant is located on the rooftop.
SolarDuct® PV/T System takes the
SolarDuct® and has PV Modules installed to
generate both heat and electricity
The Renewables Team
CA Group are responsible for the overall
roof system guarantee and to ensure
that the client/funder guarantee is
not compromised. CA design and
install the PVs in such a manner that
the materials complement the roof
guarantee negating any risks during the
life of the building. The PV panels are
factory bonded on to purpose designed
trays and delivered to site as and when
required. The physical installation of the
panels demands close attention to detail
and full training is provided to ensure
that the installer(s) fully understand their
responsibilities.
www.cagroup.ltd.uk
The primary focus of the business
is on the deployment of Solar
PV arrays for clients in sectors
that include retail, agribusiness,
commercial and light industries.
ESCO NRG Limited is a renewable
energy service company that
finances and manages small
to medium scale renewable
energy projects within the UK.
Projects generally range in size
from 100kW to 2.5MW and
provide clients with the benefits
of renewable energy with
reduced risk and capital costs.
www.esconrg.com
a range of other technologies
including heat pumps.
RenEnergy Limited is a market
leading UK installer of renewable
technologies and is micro generation
certified to install Solar PV and
Operating since 2006, RenEnergy
has gained significant market
share in the East of England and
the Home Counties by providing
clients with a bespoke and holistic
service. RenEnergy holds strong
relationships within the Solar PV
supply chain and can deliver on
projects where others can’t.
www.renenergy.co.uk
products including market leading,
radiant and warm air systems, air
curtains and combined heating,
cooling & ventilation systems.
The AmbiRad Group is Europe’s
leading manufacturer of energy
efficient heating systems for
industrial and commercial buildings.
For over 30 years AmbiRad has been
helping clients to significantly reduce
energy usage and fuel costs with
More recently AmbiRad has been
combining the benefits of its energy
efficient equipment with exiting new
renewable energy products such as
SolarWall®, providing clients with the
most energy efficient, cost effective
solutions to a whole range of
industrial and commercial buildings.
www.ambirad.co.uk
15
www.cagroup.ltd.uk/renewables
End of Life
Transportation has to consider
not only delivery requirements
at the beginning of a project
but also at disposal.
As landfill and disposal regulations
have toughened, end of life costs
have become punitive and have
become a significant cost to the
building owner. The majority of
systems supplied by CA Group are
either reused i.e. Farm buildings
etc, or sent back to the steel
mill for recycling, the residue i.e.
Insulation can either be reused
as cavity wall insulation or sent
to landfill at minimal cost.
A study by Tata Steel recognised the
need to consider the disposability
of early generation CFC and HCFC
blown foam filled panels. They
have to be removed carefully from
the building, cut into manageable
sizes and shipped to the nearest
refrigeration recycling facility for safe
disposal and capture of potentially
hazardous blowing agents.
The end result is; costs to remove
the panels from the building, costs
to cut to size, costs to transport to
the recycling centre and costs of the
recycling centre itself. As pension
funds and building owners begin
to feel this pain and the impact it
has on their return on investment
they will begin to find a solution to
these financial burdens.
CA Group
understand the
implications
of the entire
process from
‘cradle to
cradle’ through
production of
Environmental
Product
Declarations (EPDs
available as part
of its assessment
for Tata Steel
Confidex Sustain®).
Colorcoat, Colorcoat HPS200 Ultra, Confidex, Confidex
Sustain, Prisma are trademarks of Tata Steel UK Limited
Contact CA Group for more information
both materials and technical
expertise to a variety of clients across
many sectors. Operating defined
manufacturing and installation
divisions within the CA Group, we are
able to offer the client unparalleled
expertise within the industry.
Since its inception in 1983, CA
Group have developed into one
of the UK’s premier manufacturers
of roofing and cladding systems,
with an unparalleled reputation
for quality and service.
Based in County Durham the CA
Group operates nationally providing
The set-up allows for greater scope
within the organisation to focus
on customer needs, handling all
aspects of the building envelope,
from design concept to project
completion and offering guarantees
for up to 40 years. Offering a
unique range of cladding systems
with bespoke detailing CA is
able to deliver a fully engineered
building envelope solution.
To contact CA Group directly,
Please call: 01388 83 42 42
or email: sustainability@cagroup.ltd.uk
CA Group Limited
Evenwood Industrial Estate
Copeland Road
Evenwood
County Durham
DL14 9SF
When we print this document, we print it
on FSC accredited paper.
For more information on the FSC visit
www.fsc.org
www.cagroup.ltd.uk/renewables