Global demand for low cost, efficient and sustainable energy production is quickly increasing; a reduction in emissions is essential if developed countries are to meet their internationally agreed emissions targets in the coming decades.  Driven by recent discoveries and innovation in the science and technology of materials, applications based on functional materials, such as photovoltaics, fuel cells and electrolysers are becoming increasingly important.  This volume draws together 20 contributions covering the wide range of materials needed for these devices.  The book is divided into four sections on solar power, hydrogen production and storage, fuel cells and demand reduction and energy storage.  The chapters are all interdisciplinary, covering solid-state chemistry, solid-state physics, materials science and engineering. Each chapter contributor gives a comprehensive overview of the topic and illuminates what the challenges are in their particular field.  An appendix goes over the the impact of modern materials simulation and the valuable contribution tht these techniques can make to the search for new materials and the optimization of existing materials.