Editing Stirling engine (section)

=== Heat source ===
[[File:EuroDishSBP front.jpg|thumb|left|Point focus parabolic mirror with Stirling engine at its centre and its [[solar tracker]] at [[Plataforma Solar de Almería]] (PSA) in Spain.]]

The heat source may be provided by the [[combustion]] of a fuel and, since the combustion products do not mix with the working fluid and hence do not come into contact with the internal parts of the engine, a Stirling engine can run on fuels that would damage other engine types' internals, such as [[landfill gas]], which may contain [[siloxane]] that could deposit abrasive [[silicon dioxide]] in conventional engines.<ref name="LGET" />

Other suitable heat sources include [[Concentrated solar power|concentrated solar energy]], [[geothermal energy]], [[nuclear power|nuclear energy]], [[waste heat]] and [[bioenergy]]. If solar power is used as a heat source, regular [[solar mirror]]s and solar dishes may be utilised. The use of [[Fresnel lens]]es and mirrors has also been advocated, for example in planetary surface exploration.<ref name="Brandhorst-2005" /> Solar powered Stirling engines are increasingly popular as they offer an environmentally sound option for producing power while some designs are economically attractive in development projects.<ref name="Kongtragool-2003" />