Human societies produce a lot of waste, with municipal solid waste being the most common type. Instead of burying it, some places burn the waste to make electricity and reduce its volume. This is done by using the heat to create steam that powers a turbine. Other methods like gasification and pyrolysis are also used. Waste to energy plants have been around since 1904, with Europe often combining waste burning with district heating. In 2014, there was about 13 GW of waste to energy capacity worldwide.