ABSTRACT

Solar radiation is the most abundant source of energy at 219,000TWh per year. Solar thermal and photovoltaics (PVs) are the two technologies that directly exploit it. PVs tend to attract most attention, probably because it is a ‘high tech’ and modern technology that generates a product that can serve a variety of purposes. It is at the cutting edge of science and still has considerable developmental potential. Solar thermal, on the other hand, is a comparatively low tech system that has a long history in countries with generous sunshine. Another problem for solar thermal is that it does not contribute directly to reductions in CO2, nor is it linked to major industrial companies. Excess energy cannot be exported to the national grid. It is significant that the International Energy Agency omitted it from its 2008 report on renewables to the G8 countries.