sentences:  Nuclear power accounted for 36.4% of the nation's gross electricity generation of 68.3 TWh, while 57.9% was produced by hydroelectric plants and 5.7% came from conventional thermal power stations and non-hydro renewable energy sources.In addition, there were a number of research reactors in Switzerland, such as the CROCUS reactor at the École Polytechnique Fédérale de Lausanne which is currently the last one left since 2013.Switzerland uses nuclear energy only for peaceful purposes.