Bio fuels

Another important category of solar-derived renewable energy sources is biological, or bio fuels. The process of photosynthesis, green plants absorbing sunlight, carbon dioxide and water to form sugars and more complex molecules, creates so-called biomass. Biomass from plants is a major world fuel source, especially in the third world where it provides 40% f their requirements.

There are various methods of producing liquid fuels from specially grown crops or from biological wastes. Countries such as Brazil grow sugar cane specifically to be fermented into alcohol which is distilled and used to fuel cars. In other countries, maze and other high yielding oil crops are grown and processed to produce bio diesel.

Bio fuels tend to come in a liquid form and are most suitable low-carbon alternative fuels for transportation applications, but some cogeneration opportunities can be appropriate.