Sunday, 25 May 2008

Everyday Changes (How to save money and CO2)

The simple steps described here could potentially save you over a tonne of CO2 emissions per year.

Identifying the problem is only the first part of the challenge. Once we accept that there is a problem, the question becomes: "what should we do?". We are as individuals directly responsible for some of our carbon emissions, and to some extent, these can be addressed. The totals for these tips, if all applied in the modelled case, are approximately:

CO2 Saving from electricity: ~1400 kg
CO2 Saving from heating: ~450 kg
CO2 Saving from transport: ~1350 kg
CO2 Saving from all measures: 3200 kg / year

Depending on the types of car, the distribution of your energy usage, your lifestyle and where you live, these figures may change, but most people should be able to save at least a tonne of CO2 a year without difficulty. Note that the total savings above are less than the sum of all savings (see double accounting in the notes).

1) Change your electricity supplier

There are a number of packages promising green electricity in most countries at the moment. Most of these are simply greenwash, because the suppliers don't commit to building new renewable resources; instead they just allocate or purchase electricity from existing renewable sources. In the UK, there is one company I'm aware of that is different.

Ecotricity is committed to building new renewable sources of electricity. On average, they invest £1 in new renewables for every £1 spent on customers' electricity bills, which is massively different from the business model of other utilities. They also commit to matching your existing bills, so that you don't even need to pay extra for the service. At present they generate 24% of their electricity from renewable sources. Their 2007 progress report is available here and you can sign up here:

Switch to Ecotricity

Don't be fooled by companies offering you 100% renewable electricity. What matters here is fixing the problem on a global scale, not buying "clean" electricity at the expense of everyone else having "dirty" electricity.

What it costs: Nothing
CO2 Saving: 681.5 kg / year (based on UK national statistics and ecotricity 2007 statistics)

2) Switch to using long-life light bulbs

For almost all types of fitting, it is now possible to buy long-life light bulbs. The only fittings this is not currently possible for are the standard halogen 12V fittings (MR16 being the most common). Halogen GU10 fittings, candle bulbs, standard screw fittings and spots can all be replaced with compact fluorescents . A compact fluorescent will have the same light output with five times less electricity usage. A typical two-bedroom flat might have 500 watts (equivalent) of lighting in the living room, 200 watts in the kitchen and 200 watts in each bedroom. Each standard light fitting (whether screw of bayonet) can be replaced for about 33p. Non-standard fittings such as 40-watt candle bulbs or spots can cost £3.50. You can buy non-standard replacements online (for example from here:

Both of these replacements pay for themselves quite quickly:

Standard light bulbs:
What it saves: 80% of the energy used with standard lighting.
What it costs: 33pence per bulb, £3.63 for a two bedroom house (replacing 100 watt bulbs)
Annual Saving: £12.80 per bulb, £141.30 for a two bedroom house (assuming 1100 watts replaced, and four hours of use per day average)
Time to pay back: 10 days
CO2 Saving: 53.78 kg/bulb/year, or 591 kg per year for a two bedroom house

Rarer fittings (e.g. 240 watt halogen GU10 fittings, candle bulbs etc...)
What it costs: £3.50 per 40-watt bulb.
Annual Saving: £6.42 / bulb / year
Time to repay: 7 months
CO2 Saving: 26.86 kg/bulb/year.

When you have changed to energy saving light bulbs, don't forget to switch them off when not in use. If you don't bother, then any saving you get from using them will be undone. It won't shorten their life substantially to switch them off. In general, it is good practice, whether you are using energy savinglight bulbs or not, to switch all lights off every time you leave a room. Even with energy saving bulbs, doing this could generate an additional saving of £12.80 per house per year (under the same assumptions as above).

Note that some of the very cheapest bulbs can sometimes produce a harsh light, but that if you spend a bit more, you can get softer tones. It's usually worth testing a particular type of bulb before you go crazy and buy 20 of them.

3) Don't drive unless you have to.

Depending on your car, driving will emit more or less CO2 per mile. One thing to remember though is that if you drive when you could be taking a train or bus, regardless of how efficient your car is, you are unnecessarily damaging the planet.

From the transport stats at the bottom of this post, here are a couple of scenarios:

Replacing HALF your typical annual mileage with intercity bus or train:
What it costs: Nothing (the same as the petrol for your car journey)
CO2 Saving: 1558 kg/year (typical family mpv) or 476 kg/year (the most efficient car on the UK market).

Note that not driving is by FAR the most effective thing that most car owners can do to be more eco-friendly. But not driving doesn't necessarily mean taking public transport. You can also carpool. You can do this either in a traditional way (i.e. approaching someone who works at the same place as you and lives nearby), or using a more modern solution.

Liftshare (a UK based website) allows you to split the cost of a trip with someone already planning on driving. Where I live in Oxford, it is quite easy, for example, to find people commuting on weekdays to London. I was also able to find a close match for a one-off journey up to Elgin in the far north of Scotland. With this flexibility, you can substantially cut down on your costs as well as your emissions:

Replacing HALF your typical annual mileage with a two-share in a car:
What it saves: £445 (typical family mpv), £160 (most efficient car on UK market)
CO2 Saving: 925 kg/year (typical family mpv), 346 kg/year (most efficient car on the UK market)

In reality, long-distance trips and commutes are most easily carpooled, and short trips are most easily replaced by public transport. A mixture of doing both will result in the best CO2 savings, using public transport to go to the shops (or getting a lift), and using carpooling to replace your commute (or longer trips).

Notes: The cost and savings stats for both scenarios assume that you are an average UK private car owner, with an annual mileage of 8700 miles. In the car pooling scenario, I have assumed that the car in which you get your lift is equivalent to the car that you leave behind. I have also shared the CO2 savings between the person getting the lift and the person offering the lift. See Notes at the bottom of this post for the basic stats for selected car emissions.

4) Unplug electronics when not in use.

It is surprising that televisions, computers, dvd players and hi-fi units all use substantial amounts of energy when left on standby, and in some instances when switched off. My computer, for example, draws 5 watts when switched off (about the same if it's set to sleep). Turning it off at the wall when I switch it off saves this energy. My mini hi-fi uses 20 watts on standby.

It may seem a lot of effort to go to to turn off all your electronics when not in use, but there are systems to help. If you live in the UK, you can buy a remote controlled socket kit (here for example). These are independently programmable sockets, that allow you to group items under one category. So for instance, you can have your lamps on one control, your TV and associated peripherals on another and your computer on a third.

What it does: Turns off your TV and other equipment at the wall via remote control.
What it saves: Up to 50 watts for a TV, hi-fi and computer.
What it costs: £29.95
Annual saving:
Time to pay back: 7 months (this saving applies all the time)
CO2 saving: 201 kg / year

Unplugging battery chargers and other similar equipment is always a good idea. In particular, don't leave your mobile phone or laptop on charge all the time.

5) Always turn off your computer

A modern computer with an LCD screen will typically use 150 watts when switched on. When it is put to sleep, it will typically use about 5 watts (the same as when it is switched off). So you should set your computer to auto-sleep, and you should turn it off (and switch it off at the wall) whenever you leave it for longer than a few minutes.

Turning off your computer when not in use:
Annual saving: £12 per year (based on an average of two hours of extra time left on per day)
CO2 saving: 50.37 kg / year

6) Keep the heat down

Turning your thermostat down a few degrees can make big differences. If you live in a multi-room house, you can also turn radiators down or off in spare rooms and storage spaces, because otherwise you're spending money to no good effect. An even more important change is to program your boiler or thermostat correctly, so that it doesn't waste time heating the house while you're out. It is hard to quantify the saving possible from doing this, because it depends so much on other measures you've taken. Various estimates for the "average" house are available (such as here ) however.

CO2 Saving: Approx 450 kg / year

7) Turn down the temperature of your hot water tank

If your home is fitted with a hot water tank, turning the temperature of the hot water down will have a substantial effect on your home heating. In general, there is no reason to have your hot water hotter than about 55 degrees Celcius. If it is currently set to, say 65 degrees, and the ambient temperature around the tank is on average 20 degrees, then turning it down to 55 will save 22% of the energy normally used to keep your water hot.

CO2 Saving: Variable, but certain to save you money and emissions.

8) Recycle your old refrigerator, and replace it with a new model

If your fridge is more than 15 years old, you are almost certainly wasting huge amounts of money running it, not to mention wrecking the environment. It is hard to say how much energy is wasted by running an inefficient refrigerator, because there is no practical limit to how inefficient they can be. For example, the BEKO MR52 mini beer fridge uses 525 kWh / year, or about 9 times what a bigger single unit energy efficient fridge uses.

Replacing a class C fridge (Tecnik TLFR2655 - 248 kWh/year) with a class A fridge (Baumatic BR16.2A - 56 kWh/year)
What it saves: 77% of the energy used with the old model
What it costs: £202
Annual Saving: £21.12
Time to pay back: 10 years (within the probable life of the appliance)
CO2 Saving: 88.3 kg / year

The larger the fridge is, and the colder you keep it, the greater the possible energy saving by switching. Note that products with the EST recommended logo will have the best performance. In general, the manufacturer is not a good guide to efficiency. For example, you can buy EST recommended fridge freezers from Hotpoint, and you can also buy class C fridge freezers from the same manufacturer. Always check the efficiency rating and see if there is an EST logo on display. Alternatively, you can select your brand online:

Planet Prices EST recommended fridge freezers

9) When you drive, drive less aggressively and slower

Going faster than the speed limit can be very damaging to the environment. My personal experience with my Toyota Corolla 1.6 is that driving at 60 to 65 mph, and making an effort to accelerate slowly (and to avoid braking), my typical fuel efficiency is around 16 km / litre. If, on the other hand, I drive moderately aggressively, and keep my speed at 70 to 75 mph, my fuel efficiency is 14km / litre. I have been unable to find any reliable stats on this, but assuming that my experience is typical, there is at least a 10% saving to be made from driving slowly and calmly (empirically, I would say split 50-50 between the two).

Driving less aggressively for all your journeys (assuming 10% - my car manages 12.5%)
What it saves: £177/year (typical family mpv) £64/year (most efficient car on UK market)
CO2 Saving: 370 kg/year (typical family mpv) 138 kg/year (most efficient car on UK market)

In Conclusion:

With the techniques listed here, you can save over a tonne of CO2 emissions resulting directly from your own choices, and have more money left over at the end of the day, without any reduction in your standard of living. These are the easy changes, and there is no reason not to make them. There are other harder choices that we all need to examine too.

Much of the CO2 emissions that we are responsible for happen on our behalf, and not as a result of any direct action that we take. There are already good steps being taken to address these, but my view is that if we all show willing, and engage with the problem at a personal level, we will send a clear message to others (politicians and policy makers included) that something needs to be done at all levels.

Note: Other measures

In this post, I have covered changes that are easy to make, without requiring a huge effort upfront. There are effective changes that can be made which are more long-term in character, but which still pay for themselves. I will discuss these in some future posts. These include changes such as draft-proofing your house, replacing old windows with double-glazing or modern glass, increasing the depth of your loft insulation, installing a wood-burning stove for heating and so on.

I have also limited this post to changes which pay for themselves or cost nothing in the marginal sense. Other changes which can have a big saving but do not necessarily pay for themselves are things like buying organic or locally produced food, fitting your house with a photovoltaic system (solar cells), and not eating meat. These can all produce significant savings, but are the subject for a different post.

I have tried to avoid lifestyle changes in this post, but there is one change that for many of us may be essential. This is to fly less, or if flying to fly shorter distances. One transatlantic return flight will emit over a tonne of carbon dioxide. Even with all the fuel savings that can practically be made this will never change. So changing our flying habits can be a very effective measure. Over the next 50 years, we will be reducing carbon emissions from all sorts of activity (traditional transport, electricity generation, retail and so on). If flights even remain at their current level of emissions, they will account for an increasing share of CO2 emissions in the future. So it pays to think - do we really need to go on holiday to the Bahamas, when we could go to the Greek islands instead? Do we need to take a domestic flight between London and Edinburgh, when we could drive, or better yet take the train?

Note: Double accounting and other notes.

Some of the savings in this post are not additive. For instance, all the savings resulting from energy efficiency measures would be 25% less if you switched to using ecotricity. In addition, you cannot assume that the annual CO2 saving is necessarily a good guide to how eco-friendly an approach is. For instance, switching to ecotricity will result in a far greater saving, because the money you spend on your electricity is being re-invested in new renewable resources.

In the case of driving, if you follow all of the recommended steps, you would not see an additive saving, because the saving from driving more efficiently would be smaller, since you'd be driving less. It is generally important, however, to note that taking public transport is ALWAYS more efficient in the marginal sense than driving, because you have taken a service that was running anyway, rather than driving even though the bus was running that route. Public transport CO2 emissions per passenger decrease with occupancy. By the time a service becomes so popular that the bus company introduces new stock, that service is efficient enough that the impact on global warming per person is entirely sustainable.

In accounting for CO2 savings, I have tried wherever possible to be fair. This means that I have used publicly available stats for CO2 efficiency of different measures wherever possible. Some calculations are necessarily too general to be of much use.

Note: Transport stats

The average mileage of a private car in the UK is 8700 miles. Here is a breakdown of the emissions and cost (in petrol only, neglecting road tax, parking fees, insurance, congestion charges, tolls, services etc...) for a variety of cars assuming that you are an average UK driver (prices correct 26-05-2008, unleaded 111p, diesel 124p):

Large family cars / mpvs:
Subaru Forester petrol S TURBO AWD auto: CO2 - 3550 kg/year. Cost - £1705
Ford Galaxy petrol ZETEC 16V auto: CO2 - 3700 kg/year. Cost - £1778
Volkswagen Touran 1.9 TDI auto: CO2 - 2072 kg/year. Cost - £959

Executive cars:
Audi A8 Petrol 3.7: CO2 - 4396 kg/year. Cost - £2112
BMW 545i SPORT saloon auto: CO2 - 3598 kg/year. Cost - £1712
BMW 520d manual with particle filter: CO2 - 1904 kg/year. Cost - £881

Efficient cars:
Toyota Prius 1.5 VVT-i hybrid: CO2 - 1456 kg/year. Cost - £700
Volkswagen Polo 1.4 TDi: CO2 - 1386 kg/year. Cost - £641

Public transport equivalent journeys:
On Express Coach (31 grams / kilometre): CO2 - 434 kg/year. Cost - probably not much more than the petrol cost.
On a city bus (89 grams / kilometre): CO2 - 1246 kg/year. Cost - probably less than petrol + parking.
On an intercity train (27 grams / kilometre): CO2 - 378 kg/year. Cost - probably less than petrol + parking.


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