Current energy systems need a vast transformation to meet the key demands of the 21st century: reduced environmental impact, economic viability and efficiency. An essential part of this energy revolution is bioenergy.The movement towards widespread implementation of first generation biofuels is still in its infancy, requiring continued evaluation and improvement to be fully realised. Problems with current bioenergy strategies, for example competition over land use for food crops, do not yet have satisfactory solutions. The second generation of biofuels, based around cellulosic ethanol, are now in development and are opening up new possibilities for future energy generation. Recent advances in genetics have pioneered research into designer fuels and sources such as algae have been revealed as untapped bioenergy resources.