In recent years Wey valves have become increasingly common in biogas plants. One such plant can be found at BioEnergie GmbH & Co. KG in Waldmünchen, Germany, which is operated jointly by six farmers. The plant produces a total of 4.5 million kWh of electricity annually for the grid operator Bayernwerk. The plant also provides local heating for 38 buyers via a network measuring 2.3 km in length. Around 30% of this energy is generated in Waldmünchen from slurry and manure, a further 20% each from grass, maize and cereals, and approximately 10% from wheatgrass and silphium perfoliatum – a species of plant native primarily to North America.