Compressed air car The principal disadvantages are the steps of energy conversion and transmission, because each inherently has loss. For combustion engine cars, the energy is lost when chemical energy in fossil fuels is converted by the engine to mechanical energy. For electric cars, a power plant's electricity (from whatever source) is transmitted to the car's batteries, which then transmits the electricity to the car's motor, which converts it to mechanical energy. For compressed-air cars, the power plant's electricity is transmitted to a compressor, which mechanically compresses the air into the car's tank. The car's engine then converts the compressed air to mechanical
Potential energy Potential energy In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors. Common types of potential energy include the gravitational potential energy of an object that depends on its mass and its distance from the center of mass of another object, the elastic potential energy of an extended spring, and the electric potential energy of an electric charge in an electric field. The unit for energy in the International System of Units (SI) is the joule, which has the symbol J. The