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Reducing electricity consumption in the home

Inspired by the energy consumption research of a neighbour, Chris Gare, I started recording my gas (and electricity) consumption daily at the start of 2010 by simply reading the meter each day. I had moved into a new, larger house and I was curious to know how much more expensive its energy costs would be.

With the threat of continually higher electricity prices, reducing electricity consumption becomes important if you want to keep your bills in check. But what's possible in practice? What can we do to reduce our electricity consumption in a way that makes financial sense?

Switch supplier

Much is written about switching suppliers so I will not repeat it here. However, if you have never switched electricity supplier, you are likely to benefit by doing so. is a useful website to explore what tariffs are available. If you threaten to leave your existing supplier, they can usually offer you a better tariff and discounts for your future loyalty.

Buy efficient equipment

Buying "white goods" (washing machines, fridge/freezers etc) with an A+ or better efficiency rating is essential but only once old equipment has failed. The small savings made from more efficient equipment are unlikely to justify early replacement of equipment on financial grounds alone.

Change your behaviour

Beyond having efficient equipment, other energy efficiency measures make small savings individually but combined these soon add-up. For example:

  • Whenever possible run your washing machine at full load and at 40 degrees rather than higher temperatures
  • Likewise, run dishwashers fully loaded and on 'eco' settings where available. Modern dishwashers are considered to be more efficient and effective than washing by hand in the sink
  • Abandon your tumble drier in favour of using a washing line (although not practical in every home)
  • Don't use an immersion heater to heat your hot water tank if you have central heating. Electricity is far more expensive than gas.
  • Keep that big old TV, bizarrely it's probably more energy efficient than a similarly sized, modern flat screen TV
  • Use low energy light bulbs
  • Don't over fill your electric kettle. Boil only as much water as you need (it's both quicker and cheaper)
  • Don't leave consumer electronics on standby, switch it off at the wall socket (after you've shut down PCs). Most consumer electronics aren't fully "off" until they're switched off at the wall socket so until you do this it is still drawing and therefore wasting energy. If the equipment "hums" when you think you've turned it off then it definitely should be switched off at the socket.
  • If your house is lit up like a Christmas tree in the evenings but most off the rooms are unoccupied then you can easily make some savings. If you are not in a room get into the habit of switching off the lights, the TV, radios etc.

Use a real time consumption meter

real time consumption meterThere are many different real-time consumption meters on the market (see photograph). A sensor clips around the mains cable coming from the electricity meter and a wireless remote meter displays the electricity being consumed instantaneously. They are probably all fairly similar and not particularly accurate. Both the sensor and the meter need batteries and many people struggle to replace these so no longer use the meter. However, they are helpful when you are getting started as you can easily keep an eye on consumption and if the reading is too high look around to see whether something has been left on by accident.

Take power measurements

power meterA power meter (see photograph) can help you to understand how much power different types of equipment consume. This is a fairly tedious process of connecting the meter between the mains and each piece of equipment in turn and then reading the power consumption after a few hours. So to help you prioritise your effort, start with the top consumers of electricity. These are:

Equipment you can't do much about other than replace (eventually)
  • Freezer
  • Fridge
  • Tumble drier
  • Dishwasher
  • Washing machine
  • Kettle
Equipment you can turn off fully when not in use
  • TV and associated recorders, players, game machines etc
  • PC and associated add-ons such as a printer
  • Modem
  • Radio
  • Lights (although you usually can't use a power meter on them)
The "Plug-In Mains Power and Energy Monitor" from Maplin Electronics, pictured, cost me £20.

Find things to switch off

Try reading your electricity meter twice a day for a week. Read it when you go to bed at night and then again as soon as you get up in the morning - it doesn't take more than a few minutes to do. From these readings, work out how many "units" of electricity you are consuming at night when presumably you are asleep. Work out what is "on" during the night - what should be (like the fridge, a freezer, security lights, etc) and what needn't be (perhaps a PC, the modem, a radio not switched off at the wall, etc). Track down the things that you you don't need on at night. If you can switch these items off every night, over a year you'll probably notice a drop in your electricity consumption.

If you're out at work during the day, repeat the process; read your meter as you leave for work and as soon as you get back. Calculate the electricity you have consumed per hour and compare it with the electricity you consume per hour at night. The equipment that needs to be left on when everyone is out of the house will probably be the same as what you leave on during the night (fridge/freezer etc). But are you leaving anything else on during the day unnecessarily? If so, switch it off!

This may seem like a bit of chore and that's where timers can play a role.

Use timers

Consider fitting timers to equipment that tends to get left on by mistake at night (and when you're out at work) to switch them off automatically. For example, a CRT PC may consume 1.6 watts when not switched off at the back or at the wall socket. If you use it for only 5 hrs of an evening then there are 19 hours when it's wasting electricity if it's not turned off fully. 19 hours per day for 365 days per year adds-up to over 11 kWh. At 13p per unit this represents £1.43 per year of potential savings per PC. This may not sound much (and it isn't) but if you can make these savings on numerous items of equipment the combined savings may be worthwhile.

Just by automatically switching off ten items in this way (and saving 110 kWh per year) you could save £14.30 per year, which is above the minimum savings the Energy Saving Trust claims is possible. And that's before you develop the habit of switching lights off in unused rooms!

Is it financially worthwhile?

Look at your bill. See what your annual electricity consumption is. If you are consuming more than the national average of 3,300 kWh what are the reasons for this? Do you have more than 2 adults and 2 children in the house? Are you at home most of the day, perhaps working from home? Are you using electricity for heating? If your consumption is unusually high then you have the potential for significant savings.

The Energy Saving Trust estimates that monitoring your electricity consumption enables households to save between 3% and 15% off their bills. Given that the national average annual electricity consumption is 3,300 kWh per household, a 3 - 15% saving on this is 99 kWh to 495 kWh per year. Assuming electricity is priced at 13p per kWh, these savings are worth between £13 and £64 per year. Not much perhaps but they add-up year after year and your savings increase with electricity price inflation.

A power meter costs £20. Remote monitoring meters cost upwards of £30. If you buy one of each, they should pay for themselves within four years and possibly within one year. You are not likely to save more electricity if you buy more expensive meters - some are £70 or more - so the time it will take for them to pay for themselves will be longer.

Although they help, you don't need to buy meters to reduce your consumption. If you can use timers and develop a habit of simply switching things off properly then you will make appreciable savings quickly.

Monitor your progress

By recording your electricity meter at the same time every day (or perhaps once a week) you can track your consumption and evaluate the savings you're achieving. Once you start to see the reductions in consumption, this can be very motivational and help you to maintain changes in your behaviour. Below are my results for a period prior to my installing solarPV panels (after which it became more difficult to measure the savings made during daylight).

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By reducing my electricity consumption, I'm not only making savings on my electricity bill I'm also reducing my CO2 emissions.

Not content with the modest savings I could make from reducing my electricity consumption, I investigated installing a solarPV system. Read more

Written November 2011