Your definitive guide to turning your home into a power station

Solar power stations have, so far at least, proved expensive follies singularly incapable of producing anything like the energy we so hungrily need. But for ordinary home owners, matters are rather different, as the multitude of solar-panel firms proves.
Indeed, small solar panels on our roofs can actually be a solid earner. It's not that they are any better than their industrial cousins - indeed, the amount of energy they produce would ordinarily be too small to justify their existence. At best, you'll usually only produce half the energy your home requires.

But then the very generous 25-year government Feed-in Tariffs (FIT), or subsidies, come in. This means solar panel owners get paid to have them, to encourage 'green' power.

The government has been heavily criticised for its benevolence: taxpayer groups complain non-solar users - ie, the vast majority of us - are being made to subsidise solar users. Indeed, the first tariff system worked out as the equivalent to a savings account offering more than 11 per cent per year - far more than any bank.

'Had we not acted urgently to reduce tariffs, the whole Feed-In-Tariff scheme would have been entirely swamped,' Climate Change Minister Greg Barker admitted.

The cuts targeted businesses, but for homeowners, solar can still make sense, although set-up costs are high - an installed solar electricity system costs £4,500 to £8,000 per kilowatt of output (we'll come to what that means in terms of power later); which means a standard 2.2kW system is around £12,000 (including VAT).

You'll need to be confident that you're staying put, in other words - the systems only start to pay for themselves after a decade or so. You'll also need to be in the right place - a home in Plymouth produces up to 50 per cent more solar energy than less sun-drenched locations such as Lerwick.
WHAT YOU CAN EARN

Under the FIT scheme, when you install a solar system, you get paid for the amount of electricity it generates, regardless of whether you use that energy (thus reducing your bills), or you sell it back to the National Grid (making money in the process) - so the bigger the system you install, the more money you'll make.

The average home uses roughly 3,400kWh per year: the maths used to calculate output is rather complicated, but roughly a 2.5kWp (kilowatt peak) system will provide just over half your power needs. Average tax-free profits hover around £1,000 per year.

The FIT is fixed for 25 years at the rate they are offering at the time of installation. The price of electricity you 'sell' back to the grid goes up with along with the general price for units of electricity.

'Previously, solar panels did nothing to improve the appeal of a property, but if you can prove your solar panels make a tax-free profit each year, I can see them attracting more than just the sandals brigade,' says Trevor Kent, former president of the National Association of Estate Agents.

Indeed they have piqued people's interest, and companies looking to cash in on the FIT scheme are offering free solar installation to your home. They receive the profit from the FIT while you get a healthy reduction in energy costs. But buying your own panels - even with a loan - makes better financial sense.
THE TWO TYPES OF SOLAR

There are two types of domestic solar technology:
Solar PV (Photovoltaic)

This type generates electricity.
Solar Thermal

This only heats water.

At present, the solar tariffs only apply to solar PV systems, but there are plans to extend these to the simpler and cheaper solar thermal systems, which cost just £3,000-£5,000 each.
SOLAR AND YOUR HOME

So is your home suitable? South-facing is ideal - you'll lose 15 per cent for east or west - as is a 25-45 degree pitched roof and around 30 sq m of roof space (all the energy figures quoted for systems here refer to 'ideal' homes). Shade from trees or buildings will reduce performance.

Planning permission is not generally required as long as it doesn't protrude more than 200mm above the roof line. Restrictions may apply for listed buildings or conservation areas - visit planningportal.gov.uk for details.
HOW ELECTRIC SYSTEMS WORK

With solar PV systems, each panel houses a cell made from layers of semi-conducting material, usually silicon. When light shines on the cell it creates an electric field. Choose between standard roof-mounted panels (the cheapest), built-in panels which sit flush within the roof, or solar tiles, which completely replace traditional tiling. Tiles are more expensive, but costs can be offset if your roof already needs replacing. Prices range from £4,500 to £8,000 per kWp installed.

With either system, a wire leads to a 'solar meter' in your loft which shows you how much money you've earned, then the electricity travels to your home electrical system, or back to the National Grid, where you can profit.

Energy isn't usually stored or saved up for use later. If you don't use it, the energy is sold back to the National Grid. The money you get for this is - slightly - less than what you'll pay per unit on your bills, so if you've got solar, it pays to run high-drain appliances such as washing machines during the day, when your panels will be generating electricity.
HOW THERMAL SYSTEMS WORK

Solar thermal systems employ a series of tubes filled with anti-freeze that are mounted behind glass on the roof. The sun heats the liquid, which is pumped through a coil inside your hot water tank generating temperatures up to 60ºC - perfect for showering. A two-panel system (4 sq m) should provide around 50-60 per cent of your hot water needs.

Although final details are still shaky and subject to change, the Department of Energy and Climate Change (DECC) has indicated that payments of £300 per system, and 8.5p per kWh of heat produced, could be o ffered to people installing solar thermal heating at home.

You'll have to choose between 'flat plate' and 'evacuated-tube' systems. Evacuated tubes are more expensive but o er greater e fficiency. Don't forget, you will still need a regular boiler to top up the hot water at night or on cloudy days.

Budget £3,000 to £5,000 for an installed system - kits start from £1,000, but you will need DIY experience and sca ffolding to install.


full article