In Germany, the promotion of biomethane/RNG use began in 2004 with the allocation of special bonuses and lasted until 2012, when the Renewable Energy Sources Act (EEG 2012) was introduced, regulating the production of biomethane from so-called flexible cogeneration plants. In 2014, the introduction of a new law cut back on these incentives, although it did not apply retroactively, thus not impacting the plants that had received incentives up to that time.