Solar energy is from the sun's radiation energy. Most of the human energy directly or indirectly from the sun. Plants through photosynthesis release oxygen, absorb carbon dioxide, and converting solar energy into chemical energy in plant body storage down. Coal, oil, natural gas and fossil fuels by ancient buried plants and animals over a long period of geological time evolution of the form. In addition, hydro power, wind power and solar energy conversion by the. Materials LianJian solar power system The earth itself contain energy usually refers to the interior of the earth and of the heat energy and nuclear reaction about energy.