This reference provides an overview of current and alternative energy sources, including: fossil fuels, nuclear, solar, wind, tidal, hydro-electric, pumped storage reservoirs, wave, geothermal and biomass energy. Each section features a brief description of how the energy source works (typically for electric power generation), a list of advantages and disadvantages, and a short explanation of whether the energy source is renewable. There is also a summary page and a quiz for each energy type.