Why is the Sun vital to life on Earth? How does the Sun affect our weather and ocean currents? Can science solve the problems of fossil fuel shortages and climate change? The 'Why Science Matters' series demonstrates how the science we learn at school is important in every aspect of our everyday lives. Using case studies and investigations, the series describes the development of science and technologies that can improve our lives - or lead to new scientific challenges and controversies. In 'Harnessing the Sun's Energy', we find out how the enormous power of the Sun can be used to meet the world's growing energy needs. We find out about the significance of energy transfers and the role of sunlight in food chains and webs, and examples of new technologies that can provide us with environmentally-sound energy.