About 1.7 million tons of spent grain are produced from brewing operations each year in the Federal Republic of Germany. Because there is more spent grain than can be sold as cattle fodder, other uses for this product are being sought. These include composting, methane generation, and direct combustion. Researchers are using anaerobic fermentation as a means of producing biogas and using waste energy from the brewery to heat the fermenter. Combustion of spent grain can give a net energy of 12.8 MJ per kg dry grain. With biogas production, about 15-20% of the whole primary energy or 50% of the primary energy used in the boiling house could be substituted by the biogas.