Fossil fuel power stations release the energy in fossil; fuel by burning it. The thermal energy produced is used to convert water into steam that turns a turbine. All fossil fuels were created originally from plants that used photosynthesis to grow. Photosynthesis is only 3% - 6% efficient, and a fossil power stations are up to 40% efficient (up to 34% for coal, 37% for oil and 40% for gas). The energy conversions needed to produce electricity from fossil fuels are summarised below.