Natural gas refers to all natural gases in nature, including the atmosphere, water sphere, and various natural processes in the lithosphere (including oilfield gas, gas field gas, mud volcanic gas, coalbed methane, biogenic gas, etc.).Natural gas refers to all natural gases in nature, including the atmosphere, water sphere, and various natural processes in the lithosphere (including oilfield gas, gas field gas, mud volcanic gas, coalbed methane, biogenic gas, etc.).

Coal is the most important solid fuel, is a kind of combustible organic rock, coal can be divided into four categories: peat, lignite, bituminous coal and anthracite.

The photovoltaic panel module is a power generation device that produces direct electricity when exposed to sunlight, consisting of almost all thin solid photovoltaic cells made of semiconductor materials (such as silicon).