Wind and hydroelectric power, two important alternative energy sources, also produce electrical energy from the kinetic energy of a turbine within a generator. However, in these processes, the turbine is turned by the movement of wind or water over the turbine blades. Therefore, these processes do not require the combustion of fossil fuels or the emission of carbon dioxide to generate electricity.
Your Turn
Describe all the energy transformations that are required to heat your home using an electric heater. Follow the energy flow from the initial energy input from the Sun to the warming of your house.
First, the radiant energy from the Sun is converted into the potential energy contained in the chemical bonds of fossil fuel molecules. Then, when fossil fuels are burned in a power plant, the difference in potential energy between reactant and product molecules is converted into the thermal energy of water in a boiler and the individual water molecules gain kinetic energy. This kinetic energy is then transferred to the turbine and the energy is consequently converted into electrical energy in the generator. Last of all, in your home, the electric heater converts the electrical energy into thermal energy and transfers this thermal energy to air molecules, which increases the temperature in your house.