Another important point is that fermentation liquor produced by fermentation is returned to the dry fields as liquid fertilizer, permitting organic agriculture and cyclical agriculture. This system can be implemented in Germany because, under the Renewable Energy Law, the electricity power supply company operating a power plant nearest to a facility that produces electric power from renewable energy sources (for example, solar, wind, biomass) is obligated to purchase the power produced by that facility. This permits such plants to sell their electric power for a good price to earn profits. In Germany, the concept of “energy towns” that combine various kinds of renewable energy has also been established (El Bassam and Maegaard, 2004).