Smart meters are billed as the key to solving Britain's looming energy crisis.
But while a live display of energy costs and consumption may help parents bribe teenagers to spend less time in the shower, the results of a key trial indicate the meters will barely affect overall power consumption.
Between 2014 and 2019, every British home and small business will have a smart meter installed, displaying exactly how much energy is used for every activity, from boiling a kettle to watching television.
The idea is that, by observing their usage, people will realise how wasteful they are and reduce their electricity and gas consumption, lowering their bills and carbon dioxide emissions. In some trials, the meters provided information parents needed to give their children extra pocket money – or reduce housekeeping payments from working offspring – in return for turning the heating down and the lights off. But in many other cases, they yielded negligible savings – and often at the expense of family unity, with people bickering over energy usage, says Tom Hargreaves, of the University of East Anglia's School of Environmental Sciences.
Separately, the biggest trial of smart meters so far, conducted in 18,000 households by energy regulator Ofgem, reveals how difficult it would be for many people to reduce their power consumption. The two-year trial found that participating households used only 3 per cent less energy than they would have without the smart meter.
This figure is higher than the 2.8 per cent reduction in electricity consumption and the 2 per cent fall in gas use that the Government expects the smart meters to facilitate. But there is one huge qualification – the trial was conducted among a group of volunteers, not imposed upon a cross-section of the population in the way that smart meters will be from 2014.
The National Audit Office (NAO) has analysed the Ofgem research and issued a report.
In it, NAO auditor General Amyas Morse concluded that the results "do not relate to a nationally representative sample of households and so provide limited support for forecasts... [by the Department of Energy and Climate Change] The validity of some results have been constrained by design flaws, such as self-selection by participants."
The installation of 50 million smart gas and electricity meters – which allow two-way communication between the household and the energy provider – will take place between 2014 and 2019 at an estimated cost of £11.3bn.
The Government forecasts the scheme will not only recoup its costs, but generate an additional £7.3bn of energy savings by 2030 as consumers use less energy and suppliers no longer need to read meters. The net financial result of this is that the average UK household's energy bills will be £22 a year lower by 2020 than they would have without the meter.
However, the Government forecasts are based partly on projected energy savings that are being called into question, and Mr Morse points out that "costs could escalate [since] large-scale projects of this kind can take on a momentum of their own".
Advocates of smart meters point out that there is far more to the programme than saving money by watching the "in-house display", since any energy reduction, however small, will lower carbon emissions.
Furthermore, the meters provide a gateway to the fledgling smart grid, through which consumers will eventually be able to instruct their washing machine to turn itself on in the middle of the night, when electricity is cheaper, or to "export" excess energy generated through domestic wind turbines or solar panels to the national grid.
But if the very keenest consumers are able to cut energy consumption by only 3 per cent with simple energy-saving measures such as switching off the lights and taking electrical devices off standby, the risk is that the take-up of more complicated smart-grid opportunities will be low.
Experts agree that the provision of advice is key to the successful implementation of smart meters and related technology.
A sub-section of the participants in the Ofgem trial were given generic written advice as well as the smart meter and, at 5 per cent, their average energy saving was almost twice as high as those provided with smart meters.
DECC said that it has not yet finalised the level of advice it will provide for consumers.
Heating up the household
A rise in the temperature of household tensions could be an unintended consequence of the Government's smart meter rollout. An intensive 12-month study into the use of smart meters suggests they can heat up the battle of the sexes, as men tended to display a far greater degree of technological-obsession and financial control-freakery than women.
"In most cases there appeared to be a single, dominant user of the monitor – usually the man," according to an extract from the study, by Tom Hargreaves of the University of East Anglia's School of Environmental Sciences.
One participant interviewed said: "It's mainly blokes who've shown an interest in it ... we just like flashing lights and fiddling with knobs and things, don't we?" In some cases, Dr Hargreaves found the smart meters taught people valuable lessons about their energy consumption, prompting them to work together to reduce their usage. But in many other cases, displaying people's relative energy consumption in lights increased tensions, along generational as well as gender lines, with parents nagging their children.
The tension revealed in the study ranged from light-hearted to heated, and sometimes a mixture. One man, who took a keen interest in his wife's kettle use, told Dr Hargreaves: "It's hard with this family because the wife is just not interested ... I had a lot of fun to start off with. It almost caused her to move out but, you know – she threatened me ... some nasty language basically," he said before, thankfully, laughing.
Of course, smart meters will often serve as a force for good in the battle to cut energy costs and protect the environment. But, for another husband, the impact on his wife was more sinister. "She could feel the money seeping out every time she had the boiler on and, to be honest, was beating herself up over it. 'I can't have it on because I'm wasting money, but I'm cold'."