Over the past decade, countries such as Germany and the Netherlands have been harnessing solar energy through photovoltaic panels that produce electricity all year round, even on cloudy days. Now, as part of the government's commitment to develop the UK's renewable energy, the state will pay half the cost of installing solar panels.
Photovoltaics are no longer the preserve of wealthy corporations such as oil giant BP and developer Akeler. Householders and small businesses are being given the means to break the big boys' monopoly on solar energy with a £20m DTI grant fund to install photovoltaic panels on their homes and work premises.

The fund, announced by trade and industry secretary Patricia Hewitt last month, came into effect on 1 April. It offers to cover 50% of the installation costs of small-scale solar energy applications. And it adds detail to Tony Blair's March 2001 announcement of a £100m boost for the development of renewable energy – part of the UK's commitment to generate 10% of its electricity from renewable sources by 2010.

As further aids to individuals looking to do their bit for the environment, three new guides to the planning and installation of photovoltaic panels have just been published. These clear up for the first time some of the grey areas surrounding planning applications and photovoltaic installation, particularly when it comes to wiring up the electrics. And as if this was not enough, a new generation of photovoltaic products, such as Redland Roofing System's PV 700 roof panel, are coming onto the market, and they are fully compatible with other mainstream building components.

One of Britain's foremost PV evangelists is Martin Cotterell, director of Sundog Energy, a Penrith-based solar consultant and installation partner to Redland. "Photovoltaics is the only way householders can adopt renewable energy," says Cotterell bluntly. He dismisses wind turbines as unsuitable for city dwellings and water-powered solar collectors as useful for little more than hot showers in summer. Photovoltaics, however, produce electricity all year round, even when skies are overcast. And within the past year, some electricity supply companies are offering to buy back surplus electricity from householders at the same rate at which they supply it (known as net-metering).

But the path to photovoltaics is still strewn with pitfalls, including disagreeable planners, incompatible components and botched installations by cowboy builders. Not that these obstacles can dim Cotterell's enthusiasm. He points out that, even though Britain is five years behind Germany, Holland, at least the technology is now reliable and tested.

The planning issues created by the installation of photovoltaics are addressed by an annex to the DTLR's planning policy guidance note 22 on renewable energy. In basic terms, this passes responsibility for assessing the visual impact of a PV installation to the local planning authority. But it notes that, even in conservation areas: "If PV cells are fitted in the roof of a dwellinghouse so that in the LPA's view they do not project significantly above the existing roof plane, a planning application may not be necessary."

To date, most PV panels for small-scale installations are made as components to be bolted on top of finished roof surfaces. These are frowned on by town planners, particularly in conservation areas, and their installation requires penetrations through the roof surface that can lead to leaks. However, Redland's PV 700 panels have the beauty of doubling as the pitched-roof surface itself. They are equivalent in size to four standard Redland roof tiles, and come with edge details that interlock with standard tiles. As the solar panels are flush with the pitched-roof surface, they're inconspicuous, and have even won planning permission for the retrofitting on a listed Victorian school in south London.

Another problem concerns the electrics. Solar panels must be fitted with wiring, junction boxes and inverters that convert direct current electricity to alternating current, as supplied on the National Grid, and all these components must be compatible with each other. Not only are roofing contractors not renowned for their electrical skills, but until recently only a limited number of components have been available on the market.

This is where the new installation guides come in. The DTI's Photovoltaics in Buildings should answer most of a baffled roofer's questions, and Cotterell claims that the range of reliable, ready-to-use electrical components is now expanding.

However, even with new government grants, compatible components and new installation guidance, photovoltaics do not come cheap. Cotterell reckons that a typical house installation that would produce 1100 kW hours a year, or one-third of the average electricity consumption of a four-person household, would cost £5500, including grants, and could take as long as 65 years to recoup in reduced electricity bills. As Cotterell himself admits: "Photovoltaics are not a product that is sold on a cost effective basis at present. There are lots and lots of green reasons for doing so. We are the pioneers at the moment: it's like the early days of computing, when costs where prohibitive. But as the numbers of orders increases, this will break the vicious circle and prices will come down."

Grants for photovoltaic installations: apply to Energy Saving Trust at www.est.org.uk/solar.

Photovoltaics in Buildings: guide to the installation of PV Systems. DTI publication URN 02/788

Electricity Association: Engineering Recommendation G77 (covers electrical installations for small PV generators)

DTLR: Planning Policy Guidance Note 22: Renewable Energy- Annex on Photovoltaics (see www.planning.dtlr.gov.uk/ppg/ppg22/annex)

British Photovoltaic Association: www.pv-uk.org.uk

Holland leads the way

The Netherlands can claim Europe’s most ambitious single residential project yet to harness solar energy through photovoltaics. Dubbed the 1 MW PV Project and completed in 1999, it comprises 500 new-build houses for rent and sale, all fitted with photovoltaic panels, in the Nieuwland suburb of Amersfoort. A total of 12,000 m2 of solar cells at Nieuwland produce as much as 1.3 MW – 77% of the residents’ electricity needs. The PV panels are fitted in a wide variety of forms, shown left, from simple bolt-on roof panels through Redland panels integrated into the roof tiles, to entire south-facing roof pitches. Dutch government grants take the form of a 2% discount on the entire house mortgage.