There is not much heat or light being generated by the debate over green energy. David Cameron, the Conservative leader, might have won permission to put a wind turbine on his roof, but few of us are following his lead.
Less than 100,000 properties in the UK have some form of microgeneration system, such as solar panels, wind turbines and heat pumps. In comparison, German householders installed more than 75,000 solar generation systems alone last year.
The difference between here and Germany is that the German Government pays people to generate their own electricity. Germans can make a handsome profit on the 35p a unit they are paid for solar electricity fed into the National Grid, which is more than double the normal price.
The harsh truth is that money, rather than worries over global warming, is the only thing that will tempt the British to use alternative fuels en masse. And for the most part, the sums do not add up.
Wind energy is a good example. Even the respected Centre for Alternative Technology (CAT) in Wales does not recommend roof-mounted wind turbines, such as that embraced by Mr Cameron. Wind speeds around many houses are low and erratic, while a turbine is noisy and can damage a building, it points out.
One green energy expert gives warning that some customers may be conned in the Government’s push for us to adopt alternative energy sources. “There are people hoping to make a lot of money out of roof-mounted wind generators,” he says. “I don’t think they are coming at it simply to rip people off, but that’s what’s going to happen. I don’t think a credible roof-mounted generator will come on the market.”
For a more serious free-standing wind generator, you should expect to pay anything from £12,000 to nearly double that in installation charges. They are only really economic or practical for people in rural areas, particularly those not connected to the electricity grid. Even then, and taking account of electricity fed back into the grid, you should expect them to take at least 15 years to pay for themselves.
More practical for the bulk of us who are townies are photovoltaic panels, which use silicon cells to turn sunlight into electricity. Jamie Vollbracht, of Solar Century, an installation firm, says that each rated kilowatt of power costs about £7,500 to instal, on which a grant of up to £3,000 is available.
A two kilowatt installation would save 1,800 kilowatt-hours (kWh) a year, or a little more than half the typical household’s annual electricity consumption of 3,300 kWh. At current peak electricity rates, that would add up to £270 a year, with as much as £80 on top from the Government’s green subsidy, known as renewable obligation certificates.
It does not take a genius to see that it would take more than 15 years to justify a photovoltaic installation on financial grounds.
The story is remarkably similar for ground-source heat pumps. They take natural heat from the ground and boost it to useable levels using a small amount of external electricity.
The Energy Savings Trust, a government-backed group that promotes better energy use, says that a six-kilowatt ground-source heat pump will cost up to £10,000 to install and save as much as £750 a year in energy costs. That, however, is not the whole story.
Steve Moss, a builder from Buckinghamshire, who is using energy-saving principles to rebuild his house, says that heat pumps work best with underfloor heating. Mr Moss reckons that the total cost for his larger than average property will be about £20,000, including underfloor heating.
“You also need quite a lot of land,” he says. “I’m lucky, I have quite a big garden. But if it’s small, you need a bore hole for the outside pipework, which is more costly.”
And while it works in rural areas, where traditional fuel sources are expensive oil and bottled gas, it would not pay where the alternative is mains gas. A more viable alternative measure is probably one of the simplest. At their most basic, solar thermal panels operate like a reverse radiator. Water in pipes running through panels on your roof is heated by the sun and then passes through a coil in your hot water tank in a similar way to a traditional hot water system.
Although the payback period is still likely to be 20 years or more, the outlay — as little as £2,000 (before grants) — is within reach for most people. The CAT also claims that it is possible to make your own panels for £500 or so.
Do not, however, expect your efforts to do much for the value of your house. Microgeneration may push up the price of a new house, but Liam Bailey, of Knight Frank, the estate agent, says that you are more likely to add value to your home by eliminating the draughts and insulating properly.
Indeed, of all the energy investments that you can make, simply using less is the one on which just about everyone in the microgeneration business agrees. As Mr Moss puts it: “It makes most sense to insulate mercilessly, wear pullovers and turn down the thermostat. That would be the most efficient use of energy.”
Case study: hoping for a windy winter
It is early days yet for Chris Reed and Cathy Hawes, left, who had their six-kilowatt wind generator installed by Element Engineering in February, but they are hoping to end up making money from their electricity company, npower.
“There are few good deals for buying back the electricity we generate,” Mr Reed says, “but npower buys it back at the same price at which it sells. In effect, we pay the difference between what we generate and what we use. But we also get money from the Government in the form of renewable obligation certificates, which are worth about 3p a unit — and we get that whether or not we sell back the electricity.”
Mr Reed predicts that they will end up making “a few tens of pounds” from their windmill. But financial considerations were secondary for the couple, who live three miles from Carnoustie, Scotland. “We went into it having done our financial homework,” Mr Reed says. “But we would probably have done it even if we would not make a profit.”
That is just as well because break-even is a little way off. Mr Reed explains: “So far the trees have had more of an effect than we expected. We are thinking of extending the payback time from about 12 to 15 years. We are hoping for a windy winter.”
However, the summer doldrums have not put them off making plans to install a ground heat pump next year.
If you want advice on going green or how to cut your fuel bills, ask our panel of experts. To submit your questions, go to www.timesonline.co.uk/consumeraffairs
