Low Carbon Living Programme
Instant expert: lighting and appliances
For more than a century we’ve been using electricity to power our homes, providing lighting
and heat, powering labour-saving devices, and increasingly, providing communication and
entertainment. With limited supplies of renewable electricity, we need to significantly reduce
our use of electricity if we are to achieve an 80% reduction in CO2 emissions by 2050.
KEY MESSAGES
FACT BOX
The best way to reduce electricity usage in the home is to:
Electricity is measured in
kilowatt hours – kWh.

Reduce energy wasted via standby and plugged-in appliances,
which drain power.

Use appliances less frequently.

Use appliances in their most energy-efficient modes.

Have smaller, more efficient appliances.
One kWh is the energy required
to make 50 cups of tea.1
Once all that has been done, you can reduce the carbon emissions of the
remaining electricity you need to use by switching to green electricity
supplies.
INSTANT EXPERT CRIB NOTES
Electricity is a very flexible form of energy and can be put to a wide
number of uses.
Why electricity consumption varies between households
Home electricity use varies depending on a number of factors, including:

Number of occupants.

Size of home.

When people are in their homes.

The number and type of appliances people own.

How people light and heat their homes.

How these appliances and lights are used.
In the UK, one kWh of electricity
from the national grid results in
the generation of 545g of CO2.
The average household (that
uses mains gas for its heating)
uses around 3,700kWh of
electricity a year2 – of which,
around 750KwH (20%) is for
lighting, the remainder to power
appliances.
Households are the single
biggest user of energy in the
UK, using 32% – ie more than
industry or the service sector.3
A quarter of all the UK’s CO2
emissions are as a result of the
energy we use to heat and
power our homes.4
Electricity consumed by
household domestic appliances
doubled in the UK between
1971 and 2002.5
For example, a working couple might use 4,117kWh a year, compared to a
single person’s annual average of 3,084kWh, or a family with two children
(based on parents working and children at school) using 5,480kWh
electricity.6
Over four million households in
England are in fuel poverty.
Compiled Spring 2011
1
The Carbon Trust Website: Employee Awareness Posters Fact Calculations
How to live a low-carbon life, edition 2 p93, George Marshall
3
DECC UK Digest of National Energy Statistics 2010
4
At Home with Energy, p5, Energy Saving Trust (EST)
5
DTI quoted in The Rise of the Machines, EST
6
University of Strathclyde 2002 viewed 18.1.11 http://www.esru.strath.ac.uk/EandE/Web_sites/01-02/RE_info/hec.htm
2
www.lowcarbonliving.org.uk
Electricity and heating
Around 80% of UK homes are on the mains gas supply and almost all use gas for heating. 7 Households that
use electricity as their main power for heating could use at least double the amount of electricity than those with
gas central heating.8 Using electricity to heat your home is extremely carbon intensive, as 1kWh of electricity
results in 545g of CO2, compared to 185g from 1kWh of gas.
Trends in domestic electricity consumption
Electricity consumed by household domestic appliances doubled in the UK between 1971 and 2002. 9 This is
despite the energy efficiency of our homes and the products we use within them improving by 2% a year since
1970. The DTI attributes these changes to a number of factors, including:

An increase in population – more people, all using energy.

An increase in the number and range of appliances we all own.

An increase in the proportion of one-person households, which has doubled from 17% in 1971 to 30%
in 2008.10 (The amount of energy required by two people living in different households is greater than
the amount used by two people living in the same household).

Energy consumption for lighting has increased by 63% between 1970 and 2000. This is mainly due to
the shift away from rooms lit by single ceiling bulbs towards multi-source lighting from wall and table
lamps as well as multi-ceiling lights.
Finding an ‘average’ figure for domestic energy consumption is harder than you might expect as a variety of
different methodologies are used.
In his book ‘How to live a low-carbon life’ Chris Goodall gives a figure of 3700kWh as the average electricity
consumption for a home which has gas central heating.
OFGEM use a ‘typical’ energy consumption figure of 3300kWh electricity and 16,500kWh gas when calculating
average energy bills – a figure based on median average consumption.
DECC have produced an interactive map that gives average energy consumption calculated per domestic
meter point. This gives average consumption figures at 14,898 kWh gas and 4,709 kWh electricity. The higher
electricity figure here is in main because it includes households that use electricity for heating, bring up the
average. You can get area specific averages for your area from
www.guardian.co.uk/news/datablog/interactive/2012/apr/02/energy-use-map-electricity-gas
7
How to live a low-carbon life, p 83, George Marshall
Based on LCWO household footprinting work
9
DTI quoted in The Rise of the Machines, EST
10
Office of National Statistics General Lifestyle Survey 2008
8
2
www.lowcarbonliving.org.uk
LIGHTING
Background
The average home has around 25 lightbulbs in use. Around four of these are in high-usage locations – being on
for more than three hours a day. Overall, we are clocking up around 27 hours usage in total per day. 11 On
average, these use 750kWh a year – or 20% of domestic energy.12 There are three types of lightbulb:
Conventional incandescent bulbs
These work by passing electricity through a thin metal element or filament, which then emits light. It’s a very
inefficient process, with most of the energy being radiated as heat. They are cheap to buy, can be dimmable,
and are easy to find. Halogen bulbs are also incandescent bulbs. They are slightly more efficient at generating
light, but cost more. In 2009, the highest wattage incandescent lightbulbs were withdrawn from sale.
Fluorescent bulbs
These use electricity to make a coating on the bulb fluoresce. These bulbs include the long tube lights found in
offices, as well as the small ‘Compact Fluorescents’ (CFLs) used at home, in which the long tube is folded over
many times. These are the bulbs people traditionally think of as ‘energy-efficient’ bulbs.
Fluorescent bulbs tend to be more expensive, but last up to ten times longer and are four to five times more
efficient than conventional bulbs at generating light. CFLs are often sold at a subsidised rate. First generation
CFLs tended to buzz and have a cold light, and could take time to warm up; however they have improved, and
dimmable versions are now also available.
Light Emitting Diodes (LEDs)
LEDs are semiconductor devices that are very efficient at turning electricity into light. They are very cheap to
run but currently very expensive to purchase; however, they may one day be commonplace.
The key to reducing energy consumption by lighting is:

When you aren’t in the room, switch them off.

Change bulbs to energy efficient CFLs, starting with your high-usage bulbs. Replace bulbs even if they
haven’t blown – the payback in both carbon and financial terms can be as short as a few months.
If every UK home installed three CFLs it would save enough energy to pay for all the street lighting in the UK. 13
Mythbusting
Many people claim not to switch to CFL lighting because they don’t like the light. However, an Energy Saving
Trust study ran a blind test in a shopping centre where they set up two identical living rooms, one lit by
conventional incandescent lighting, and the other using CFLs. Shoppers were asked which was which, and
which light they preferred. Most people couldn’t tell, and the majority preferred the light from the CFLs.
Inefficient appliances and lights do generate heat as a by-product, which can help heat up your home. Although
this can reduce your overall heating requirements, it’s not a great argument for using inefficient appliances in
your home. For a start, generating heat by electricity is less efficient in carbon terms than generating heat using
gas, the preferred heating fuel of UK homes. Secondly, for much of the year we want to cool rather than heat
our homes, so this additional heat is not as welcome as it might appear.
11
How to live a low-carbon life, 2nd edition, p 84, citing the Market Transformation Programme
How to live a low-carbon life, p 84
13
The Rise of the Machines, EST. 2006
12
3
www.lowcarbonliving.org.uk
APPLIANCES
When considering the energy-use of appliances you need to bear in mind two things – the energy they
consume when you run them, and the energy used to make them in the first place.
Which appliances use the most energy?
The energy consumption of domestic appliances varies hugely depending on the efficiency of the appliance,
how often you use it, and HOW you use it. The table below gives an indication of the likely energy consumption
of different appliances over a year.
Appliance
average annual kWh
Lighting
750
Fridge-freezer (fridge)
(250) 500
TVs (based on a home with 2-3 sets, excluding set top boxes etc)
500
Tumble dryer
400
Dishwasher
300
Washing machine
270
Kettle
150
PC
150
Mobile phone
8
Source: How to live a low-carbon life by Chris Goodall (except mobile phone: LCWO calculation)
Reducing the energy used by household appliances
Using appliances more effectively
Are you getting the most out of your appliances? For example, by only washing full loads in the dishwasher,
and only using a tumble dryer when it’s a rainy day, you can reduce the number of times you need to use an
appliance. Another easy energy saving habit to adopt is turning lights off when you leave a room.
Check you are using appliances at their most efficient setting – eg washing clothes at 30ºC, and only putting as
much water in a kettle as you need.
Avoiding standby
Critically, what you do when aren’t using an appliance can have a big impact. The average household is
wasting 400 kWh a year by leaving appliances on standby14. The ‘vampire load’ is the energy drained by our
appliances when they are not in use. The International Energy Agency estimate standby is responsible for 1%
of global carbon emissions and 5-10% of domestic electricity usage.15
Appliances left on standby are a major cause of energy waste – but some appliances, especially those with
transformers, use power even when switched off. Transformers may be visible as a black box on the plug or
cable, but often inside the product. They can be found in lots of appliances including printers, computers and
radios. The solution is simple – switch appliances off at the wall. Mobile phone chargers, for example, will
continue to draw power when they are plugged in and switched on, even when no phone is connected.
14
15
How to lead a low-carbon life, edition 2, p94
IEA 2007, http://www.iea.org/papers/2007/standby_fact.pdf
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www.lowcarbonliving.org.uk
Choosing more efficient machines
Many electrical appliances carry the EU Energy Label. This rates products on their
energy usage, from A (best) to G (worst). Cold appliances also have a top rating of A+
or A++. Be aware that, because of the criteria used in calculating ratings, a top energy
rating does not necessarily mean the lowest annual electricity consumption. So be sure
to also look at the figure for the estimated annual electricity consumption, which should
also be on the label.16
For example, ratings for freezers takes their volume into account, so an American-style
fridge may have a better rating than a small fridge-freezer, as it’s more efficient per unit
of volume – but it may actually use more energy overall.
Another energy rating to watch for is The Energy Saving Trust
Recommended logo. This also endorses products where there isn’t a
statutory EU Energy Label, such as glazing, televisions with integrated
digital decoders (IDTVs), and boilers.
When changing appliances, the size of appliance can have a big impact on overall
energy consumption, eg LED TVs are more efficient than old cathode ray tubes (CRT)
ones per screen inch, but these savings are wiped out by buying bigger sets.
When is it worth trading your current appliance for a more energy-efficient one?
When deciding whether to replace an old appliance with a more energy-efficient one, you have to weigh up the
savings achieved in running costs with the loss of chucking out the embodied energy of a perfectly serviceable,
but inefficient machine – ie looking at the ‘payback period’.
The outcome of this calculation will vary depending on the age, use and efficiency of your machines. The
appliance that has seen the greatest improvement in efficiency is the fridge-freezer, so this is the one most
likely to benefit from being replaced.
Chris Goodall in How to live a low-carbon life reaches the following conclusion: washing machines and tumble
dryers – it’s more important to use your current machine efficiently than to replace them. An old fridge-freezer is
probably worth updating.
Some definitions
Embodied energy
Embodied energy – sometimes referred to as ‘embedded energy’ – is the energy used (and therefore the CO 2
emissions) in manufacturing, packaging and transporting a product, material or service. So when calculating
the CO2 savings from a new energy-efficient product such as a boiler or washing machine, its embodied energy
needs to be taken into account. Usually the energy saved in use will quickly compensate for the embodied
energy, but in some cases – such as small urban wind turbines – it may be that a product will use more energy
in its manufacture than it will save across its lifetime. (Source and text: BBC Bloom site glossary).17
Payback period
Acquiring a new, efficient appliance results in our having to make an initial upfront investment in that item – but
results in savings over time thanks to reduced running costs. The payback time is how long it takes for these
savings in running costs to reach the level of the initial investment. Payback can be thought of in financial
terms, or alternatively, with regard to carbon savings – the point at which the saving in carbon terms reaches
the cost in carbon terms of making the item.
16
EU Energy Label http://www.energy.eu/focus/energy-label.php
17
http://www.bbc.co.uk/bloom/glossary.shtml
5
www.lowcarbonliving.org.uk
Fuel poverty
Between 2003 and 2008 the number of households in fuel poverty more than doubled to 4.5million as fuel
prices soared.18
The following information is from the Poverty Site: www.poverty.org.uk.
Households are considered by the Government to be in ‘fuel poverty’ if they would have to spend more than
10% of their household income on fuel to keep their home in a ‘satisfactory’ condition. It is thus a measure
which compares income with what the fuel costs ‘should be’ rather than what they actually are. Whether a
household is in fuel poverty or not is determined by the interaction of a number of factors, but the three obvious
ones are:
The cost of energy.
The energy-efficiency of the property (and therefore, the energy required to heat and power the home).
Household income.
 3.3 million households in England were classified as being in fuel poverty in 2008 (16% of all households).
This is almost three times the number of households in fuel poverty at the low point in 2003, and there have
been increases each year since 2003. It is, however, still lower than the number in the mid-1990s.
 Fuel poverty is most common among those living in private rented accommodation: averaging from 2006 to
2008, 18% of households in private rented accommodation were in fuel poverty compared to 13% in other
tenures.
 Despite their much lower average incomes, those in social rented accommodation are no more likely to be in
fuel poverty than owner-occupiers. This is partly because very little social housing is energy inefficient (see the
indicator on energy efficiency) and partly because social housing tends to be small, both factors meaning that
relatively little fuel is required to keep the home warm.
18
DECC
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www.lowcarbonliving.org.uk
APPLIANCE FACT FILE
Much of the information below is from Chris Goodall’s informative book, How to live a low-carbon life, published
by Earthscan. (Second edition) Thanks to Chris for so generously sharing his material.
Kettles
Kettles are one of the most used appliances in the kitchen, with the average family boiling the kettle around four
times a day – that’s 1,500 times per year.19 Kettles account for nearly 30% of all domestic energy cooking
energy consumption.20 Key to efficient use is to only boil the amount of water you need.
What’s the most efficient way, in energy terms, to boil a mug of water….?
Electricity is more carbon-intensive than gas, so in theory gas is more efficient in carbon terms. However… this
is offset by the fact that electric kettles have automatic switch-offs, whereas gas kettles are more frequently left
to boil. However… people tend to overfill electric kettles.
So, on balance, if you only boil what you need, in a frequently-descaled electric kettle, there’s not much in it.
Washing machines
95% of households have washing machines and they are used an average of 270 times a year. As 80% of the
energy used is for heating the water, the cooler the water, the less energy used.
The Energy Saving Trust recommends the following: “Wash at 30ºC as often as you can. Most modern
detergents work well at 30ºC or 40ºC. Washing clothes at 30ºC rather than higher temperatures uses around a
third less electricity over a year.
Try not to use half-load settings, but wait for a full load instead, and dry clothes outside as often as possible. If
you need to tumble dry, adding an extra spin cycle on the washing machine will mean you need to tumble dry
for less time – the extra spin uses less energy than running the tumble dryer for the extra time.”
Tumble dryers
These are owned by 40% of households and consume an average of 400kWh a year. Line drying is always the
best option. Surprisingly, drying clothes indoors on radiators can use lots of energy – as much as 50% of that of
a tumble dryer. This is because energy is used to evaporate the water, which then condenses on windows or is
lost by air circulating outside.
Dishwashers
Owned by 25% of households, a debate rages as to whether it’s better to wash your dishes in a dishwasher or
by hand. A dishwasher can be efficient if it is fully loaded and uses an eco setting. It may also use less water –
however, the appliance can use energy when left on standby. Washing dishes by hand can be made efficient if
the water is heated by gas (which results in less carbon than electric water heating) and you are careful about
the amount of water used.
Cold appliances
The average household owns around 1.5 cold appliances – most homes have a fridge or fridge-freezer, but
less than half have a stand-alone freezer. Cold appliances have seen some of the biggest improvements in
energy consumption in recent years, and A+ and A++ grades have been created to reflect these gains.
Fridge-freezers have seen some of the biggest improvements in energy efficiency, and as such with this
appliance it is worth considering upgrading from an old to a new one… so long as you resist buying a larger
model! When choosing a new appliance, remember to look at the overall energy consumption, not just the
energy rating on the EU label.
Other ways to improve efficiency of an existing cold appliance is to minimise opening the door, position it in the
coldest room in the house, keep the coils at the back free from dust, run it at the highest possible temperature
(whilst being mindful of food safety), eg 18ºC for freezers. According to the Energy Saving Trust, “A full freezer
might use a tiny bit less electricity than a half full freezer, however the amount of electricity used will be much
more dependent on other factors such as where it is located and how often the door is opened.”
19
20
www.energysavingtrust.org.uk/cym/Home-improvements-and-products/Home-appliances/Kettles, viewed 18.1.11
The rise of the machine, EST
7
www.lowcarbonliving.org.uk
Televisions
With households averaging two to three sets, cumulatively these can use more electricity than many other
appliances. Older CRT sets are less efficient per square inch of screen than LED screens, but these gains are
usually wiped out by households upgrading to a larger TVs. Plasma TVs have even higher energy consumption
rates. As well as the actual TV, the plethora of associated devices including DVD players, set top boxes and
games consoles all add to the use of electricity – and all continue to draw power when left on standby.
Computers
Laptops tend to be much more efficient than desktop PCs and flat screens, and more efficient than old-style
CRT monitors. The Energy Saving Trust has this to say on the subject:
“A new LCD monitor in 2010 will typically use about 32W in on mode and just over 1W in sleep mode. A CRT
monitor from 2000 will typically use about 90W in on mode and around 4W in sleep. So if the two screens are
used for the same amount of time, the new LCD will use 36% less energy when on and 75% less energy when
in sleep. Efficiency has been improving for any given technology. Energy consumption is proportional to screen
size (area), therefore the larger the screen the more energy it will consume.
How much a PC uses depends on its age, older models tending to be less efficient, as well as its processing
power and what its doing. The greater the processing speeds the more energy used, in part because a bigger
chip gives off more heat and so needs a bigger fan. A computer on using its screensaver is still using significant
energy – and even when switched off, a PC may draw power, unless turned off at the wall.
Laptops are specifically designed to use less power, to maximise their battery life, so a laptop will usually be
much more efficient than a PC. It’s better to use a laptop plugged into the mains than running off its battery,
when possible.”
Mobile phones
The mobile phone charger is often held up as the poster boy of bad energy practices – but in reality, what
impact do these appliances have?
A mobile phone charger uses 5W when charging a mobile phone, which it might be doing so for one hour a day
– this equates to 1.825kWh a year.21 And a modern phone charger with no phone attached uses around
0.01kWh a day when plugged in (an older one may use up to 0.07kWh)22 – which equates to 7.2kWh a year.
This amounts to a total of under 10kWh a year per mobile phone.
Although this is only a small amount per phone, it’s worth bearing in mind that there are more phone chargers
than people in the UK. Collectively, mobile phone chargers do have a significant impact, so should still be
unplugged when not in use.
FURTHER INFORMATION
How to live a low-carbon life by Chris Goodall, published by Earthscan – The low-carbon bible.
Energy Saving Trust website: www.energysavingtrust.org.uk. The FAQ section in particular has a
wealth of information, helping you answer every conceivable question householders may throw at you about
the use of energy in the home.
This work is part of the Low Carbon Living Toolkit and is licensed under a Creative Commons AttributionNonCommercial-ShareAlike 3.0 Unported License. If you have any questions or tips to suggest please email them to us
at lowcarbon@hotmail.co.uk v 2 16/10/12
Whilst we have made every attempt to ensure the accuracy of this leaflet, this information should not be relied
upon as a substitute for formal advice. LCWO will not be responsible for any loss, however arising, from the
use of, or reliance on this information. Low Carbon West Oxford is a registered charity 1135225.
21
22
http://www.mhi-inc.com/Converter/watt_calculator.htm
Sustainable Energy – Without the Hot Air, David MacKay
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www.lowcarbonliving.org.uk