Renewable energy sources include biomass, geothermal energy, hydropower, solar energy, and wind energy. They are called renewable energy sources because they are replenished in a short time. Day after day, the sun shines, the wind blows, and the rivers flow. We use renewable energy sources mainly to make electricity.

Renewable energy sources can be replenished in a short period of time.  The five renewable sources used most often are:

• biomass - including wood and wood waste, municipal solid waste, landfill and biogas, ethanol, and biodiesel
• water (hydropower)
• geothermal
• wind
• solar