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Solar power is the shining beacon of the renewable energy world. Increasing fossil fuel prices alongside anthropogenic global warming are seeing a fresh drive to explore whether solar power could be the answer to the fuel crisis. Enough sunlight hits the earth’s surface in a single hour to match the world’s energy demands for an entire year, yet current technologies are simply failing to match this incredible potential. Today there exist two main techniques to convert sunlight into electricity, either directly using photovoltaics, or indirectly using concentrated solar power.
Photovoltaics (PV) rely on semiconductor solar cells, which, when exposed to light generate electrons and create a current. PV is one of the fastest-growing energy technologies, with an estimated turnover of EUR 10 billion in 2007. The most widely used and well developed solar cells employ crystalline silicon, but these are quickly reaching their theoretical efficiency limit of 29%. Other functionalities are being investigated for use in solar cells –a particularly successful example being multijunction PV cells, which consist of multiple thin films of semiconducting materials. With this design, a new world record for sunlight-to-electricity conversion efficiency was set in 2010 by ‘Spire Semiconductor’, a solar technology company based out of Massachusetts USA, whose triple junction gallium arsenide solar cell achieved conversion with 42.3% efficiency.
Alternatively, concentrated solar power (CSP) systems use large lenses or mirrors to focus and concentrate sunlight onto a small area. The focused light creates incredibly high temperatures which are used to drive steam turbines in a similar way to conventional power plants. The process is highly efficient and a study by Greenpeace International estimated that CSP could account for 25% of the world’s energy demands by 2050.
Despite these sunny figures, the Department of Energy and Climate Change (DECC) announced £34 million worth of cuts to low carbon and renewable energy spending last July. When it comes to energy, it seems the government’s persuasions are not so green. Britain lags sorrowfully behind many of its EU counterparts in terms of renewable energy usage; a mere 5.1% of the total energy usage came from renewable sources in 2007 compared to 15.1%, 20% and a staggering 52% from Germany, Spain and Sweden respectively. Britain will see a long road to reach the EU agreed generation of 15% of energy from renewables by 2020.
The achievement of this goal was further hampered last week when a formal review on the feed-in tariff (FIT) system put in place just 10 months ago was announced. FITs provide government guaranteed price for electricity sold to the National Grid by renewable electricity generators. The system, which was originally introduced to the EU by Germany, has seen much success outside of Britain, particularly in Spain. FITs here saw the development of the world’s first commercial solar tower using CSP technology. It is predicted the plant will be able to generate enough electricity to power 200,000 homes. So what prompted the change in heart from the British government?
Numerous field-based solar arrays have recently emerged, threatening to leave FIT funds unavailable for the home owners, businesses and local communities for whom they were intended. The government have subsequently implemented a 50 kW cap on any projects, the size of which will include commercial and community building installations. With the promise of further cuts to come, there are concerns that the PV industry will be put in jeopardy. Instead of making cuts in a ‘knee-jerk’ fashion, the government should embrace these developments and attempt to stimulate growth in the UK PV industry. Many investors will undoubtedly be shelving projects for the manufacture and installation of solar cells -investors who would have otherwise been injecting some much needed cash into the market. With cuts to both the FIT scheme and to research and development funding, it seems Britain’s solar industry is destined to be left in the dark.