Rising fuel prices during recent years and the threat of global warming have reinforced public and scientific interest in the issue of sustainable energy, with the term sustainability understood as having economic, environmental and social dimensions. Renewable energy is seen as an effective means to address several problems simultaneously, including climate change, exploitation of non-renewable resources, the high volatility of energy prices on the global markets, dependency on fuels from politically unstable countries (energy-insecurity) and the transfer of wealth to these countries. This...