Solar thermal heating of the anaerobic digester system can sustainably uphold the digester operation temperatures in the thermophilic range in the tropics throughout the year. Though Solar hearting has already been used in digester systems, it has mainly been utilized to raise temperatures form the psychrophilic to mesophilic range. This book gives an extensive literature on biogas potential and production of various feedstocks and design adn sizing approcah for anaerobic digester systems.