Smart meters turn up the heat on those with money to burn

Will showing electricity use encourage householders to conserve energy, or is it just a gimmick?

You may not know it yet, but within a decade the government will have dragged your electricity meter from under the stairs and into your daily sight.

In plans outlined last month, every new meter fitted after next May will be a smart meter that will tell you how much electricity you're using and how much money it is costing you - all in real time. The idea is to cut bills and carbon emissions, as our homes account for more than a quarter of the UK's CO2 output.

Depending on whose figures you believe - and there are more than a dozen reports by people as varied as Northern Ireland Electricity, the Energy Saving Trust, Horstmann (a maker of smart meters), the Green Alliance and Sustainability First - these meters help cut power bills by between 3% and 15%. With average UK electricity bills at £383 a year, smart meters could mean big savings.

Big savings

To discover how (or whether) the meters influence your behaviour, I spent a week living with each of the three main ones available now and imminently. First, I sought a common definition of what a smart meter is. Ofgem describes them as devices that offer customers "clearer information about the energy they are using", while Energywatch lists features they should include - notably, a display that tells you what you're using in pounds, an indicator of low, medium and high electricity consumption, and an internal memory to store energy history.

In my experience of the Electrisave, HomeCO2meter and DIY Kyoto Wattson, you get a wireless transmitter to clip between your fusebox and electricity meter, plus a wireless display that talks to the transmitter and sits somewhere prominent in your house, telling you how much cash you're burning every second.

The psychology behind the meters is simple: if you can see how much money you save by turning off an unused light, you'll switch it off. Smart meters, so the theory goes, reconnect us with our energy use. My experience started fairly well. Once I'd worked out which wire to clip the transmitters to, each meter was installed in a matter of minutes, although I had to read the manuals on all three. "One of the big issues is how we can ensure people want to install them and keep coming back to them," says Luke Nicholson of sustainable designers More Associates.

To test the changes each meter made to the amount of electricity we use in our three-bedroom house, I took meter readings before and after each week. I don't pretend the results were scientific - they were taken mostly in April, as the days became longer and we used less lighting in the evenings - but the surprising thing was how similar the readings were despite the different designs of the meters.

Justin Rowlatt, who spent a year living a green lifestyle as BBC TV Newsnight's Ethical Man, notes on his blog ( how he cut his electricity bills by 22%. He told me he credited a large part of that to the Electrisave.

In my house, we used between 35kWh and 40kWh each week while living with the meters, much less than half the average UK home. That's nearly the same as what we used before the meters, though, which is probably down to the fact we already fanatically turn things off.

What's interesting is how people engage with the meters. Dale Vince, the founder of Ecotricity, describes how his wife and two children "went round the house switching off lights one by one, watching the watts go down. I was surprised by the degree to which it engaged them all."

Silver bullet

My fiancée confessed she'd ignored the HomeCO2meter and Electrisave, but was engaged by the Wattson because "it looked good and showed how much you were using in pounds, and so I immediately started turning things off". For me, the meters gave a pointed reminder of how much electricity you need for anything to do with heat or water. Every time we used the kettle, toaster, dishwasher or hairdryer, the meters went off the scale.

If you don't already turn lights and standby appliances off, smart meters could be a good nudge: the Energy Saving Trust reckons the average UK household wastes £37 a year just by leaving appliances on standby. On just one day I found that my Sky HD box uses 47W doing nothing on standby (it uses 50W powered up) and my Denon DAB hi-fi uses 17W to flash a clock while on standby ( 25W on).

As many will point out, smart meters aren't a technological silver bullet for fighting carbon emissions. The Energy Retail Association dismisses the current ones as a "gimmick measure", partly because they don't measure gas use.

Nicholson describes today's meters as "at the same point as MP3 players were before the iPod. Most are so crude I'm surprised the research even reports 5% cuts, which just shows people have a pent-up enthusiasm to save energy. DIY Kyoto's Wattson is the closest we've come yet to an iPod of smart meters - they're offering something cool and desirable."

Despite its high price and the fact we used the most units while living with it, the Wattson was the favourite in my house, which is encouraging as the company has plans to develop products monitoring gas and water in the future.

It's clear smart meters will become universal and almost certainly cut bills. What's impossible to measure definitively is exactly how much carbon and cash they'll save, and whether the mass-market ones given away for free by energy suppliers next year will be as smart as the Wattson.

Measuring the meters

For Affordable, clear display
Against Clunky interface, ugly design, no memory for tracking
Verdict Utilitarian and basic way to see your electricity consumption in pounds and CO2 energy consumption

For Small, can see previous electricity usage
Against Fiddly interface, feels cheaply built, not yet available - though it is "coming soon"
Verdict Affordable and functional

DIY Kyoto Wattson
For Handsome design, simple visual clues to energy consumption
Against Expensive, can't display energy history without a PC
Verdict An attractive gadget, more about influencing your mates than saving cash

Wattage and current meter
For Cheap, simple to operate
Against Can't measure lighting, requires a lot of effort for long term monitoring
Verdict Useful for converted greenies, but not much use for everyone else

· Adam Vaughan tested each smart meter for a week. Readings were taken between April and May 2007

· Adam Vaughan edits and blogs at
