The largest single source of energy for thermal power plants is gas (liquefied natural gas, or LNG), which accounts for 25% of the total. Next comes oil, at 18%, followed by coal, at 15%. Various renewable energy sources are also used, like solar energy, geothermal energy (using heat from the earth), and also wind and wave power. One interesting power source is trash! At nearly 160 out of the 1,900 waste disposal facilities around Japan, the energy from incinerators is being used to generate electricity, producing about 659,000 kilowatts of power that would otherwise "go up in smoke."