Biomass is the only renewable energy source which can deliver electricity, provide heating, cooling and fuel in form of solid, liquid and gas. Biomass supplies more than 11.5% of the world's primary energy and about 79.7% of the world's energy consumption. In 2012, about 194.8millionton of renewable energy was consumed in the world and about 0.1millionton was consumed in Iran. Biogas is produced by anaerobic fermentation. Global biogas capacity will reach 22,000MW by 2025. European biogas electricity production in 2006 was 17,272GWh per year, of which 7338GWh was by Germany alone. Biogas now represents 1.2% of the annual production of electricity and nearly 10% of renewable energy, with an installed power close to 1500MW. Global biogas installed capacity is expected to achieve moderate growth over the next 12 years, reaching 22.040MW by 2025 and making a compound annual growth rate (CAGR) of 7.2%, a recently published analysis by Global Information Inc (GII) showed. The world biogas market has grown considerably between 2001 and 2011, with installed capacity expanding to 8.377MW in 2011 from 2.388MW in 2001. This equals a CAGR of 13.4%. The potential of biomass sources in Iran is estimated to be 132millionton (oil equivalent) in the form of agricultural and forest wastes, livestock wastes, municipal wastes, sewage and industrial wastes. Taking into account the usual amount of biogas yield from agricultural wastes, animal wastes, municipal wastes and industrial and municipal wastewater and with good safety factor, biogas in Iran will generate about 16146.35millionm3 which is approximately 323petajoule (1015) of energy. This paper investigates the potential of biogas production from biomass sources in Iran and presents the energy carriers, examples of biogas production, applications and quantitative potential of different sources in Iran.
