With the introduction of the Climate Change Levy in April 2001 and the Government's commitment to producing 10% of UK electricity from renewable sources by 2010, green is also essential. Energy companies are striving to hit these targets in different ways, with one of the more surprising technologies coming to the fore being photovoltaics (pvs).
PVs convert solar energy into electricity and until recently they have been seen as financially unviable due to long payback periods. However, the visibility of the technology has ensured its future; rather than being used simply as an energy device, installations have mainly been on showcase buildings, used as a tool to demonstrate a company's environmental and forward-thinking policies. But the market may be set for change.
Speaking at the conference Solar power design and installation – your opportunity to deliver the new technology, David Williams, managing director of Colt International described the market as "in transition". He reported global market growth of 25% year on year from 1987-1998, and a drop in prices over the same period from £20/Wp to £4/Wp.
Of these costs, Williams stated that only 55% was accounted for by the actual pv units, 20% was required for installation, with the remaining 25% required to balance the system. These are both areas where trained and skilled personnel are lacking at the present time.
The UK is currently lagging in the take up of pvs, with the USA having 45% of the world market and Germany accounting for over 80% of the EU's 24% market share. But with government-backed incentives and European grants becoming available, several schemes are getting the go-ahead and the large-scale application of pvs is becoming realistic.
James Marsh of the Department of Trade and Industry (DTI) demonstrated the Government's support for the technology with the news that 20% of the £3.5 million annual budget for its renewable and new energy technology programme will be used for pv research.
Several projects already built and proposed for monitoring include the Guardian Royal Exchange offices, Ipswich and The Solar Office (above).
A DTI solar research, development, dissemination and demonstration programme is set to run for at least 20 years and this, Marsh said, will include electricity-producing pvs.
He also spoke of three new initiatives announced by the DTI in 2000: a domestic field trial; a large-scale building integrated pvs (bipv) demonstration; and a call for proposals into the research and development of pv systems and components. Response to the latter indicates the level of interest now being shown to this technology: 28 proposals were received after the first call, of which ten can be supported by the £1 million budget available.
The domestic field trial is intended to "give learning opportunities" for developers and contractors and will include new build and major refurbishment projects. The aim is to install 100 pv systems in "clusters" of 5-25 kWp systems. At the time of the conference 25 proposals had been received, with a total required funding of £4.5 million. Marsh stated that of the schemes that run, on average 50-70% of costs will be government grant-funded.
Another incentive has been provided to the domestic market by specialist Solar Century. The company has arranged with Natwest Mortgages a solar mortgage, which spreads the cost of the system over 25 years at conventional mortgage rates, letting homeowners pay the installation off gradually.
Despite these advances in the industry, costs are still an issue. The efficiency of the units is still very low (around 15%) and the high capital costs mean long payback periods.
However, James Marsh states that costs of bipv can be offset by "taking into account the avoided costs of the parts the pvs are replacing", such as roof tiles or cladding. This is backed up by the British Photovoltaic Association (PV-UK), which claims that pv "is increasingly competitive as a building component" and "already less expensive to install than prestige forms of conventional cladding".
Buildings are also being designed so that pvs can be installed after handover, enabling owners to complete the installation when finances allow. The role of contractors and installers is vital on such schemes to ensure that this future-proofing works. All components must be exactly positioned for a system to be correctly fitted at a later stage.
Currently, education and training are needed for all aspects of pv technology, says PV-UK. A list of companies offering "training and teaching" is provided on its web site (www.pv-uk.org.uk), with details of what each provides.
It was stated by delegates though that this process should be simple. Use of "everyday electrical installation methods" was highly possible, with an aim that "local electricians should be able to install systems". One issue is earthing and ground fault protection. There were said to be "lots of views on how to earth pvs" as this cannot be done in the conventional manner and they may not even require earthing. Waterproofing and safety are of prime importance. The other main difference is that pvs produce dc power, which must then be converted for use to ac by an inverter.
However, with delegates stressing standard installation procedures should be possible and predictions that thin film pvs could be applied by spray gun in future, speeding up and simplifying the process, the market is open for entrants.
Source
Electrical and Mechanical Contractor
