Geothermal Energy
- Hot water or steam extracted from geothermal reservoirs in the earth's crust. Water or steam extracted from geothermal reservoirs can be used for geothermal heat pumps, water heating, or electricity generation. [EIA Energy Glossary]
Hydropower
- Electrical energy produced by falling or flowing water.
Solar Energy
- Electromagnetic energy transmitted from the sun (solar radiation). The amount that reaches the earth is equal to one billionth of total solar energy generated, or the equivalent of about 420 trillion kilowatt-hours.
Wind Power
- Kinetic energy present in wind motion that can be converted to mechanical energy for driving pumps, mills, and electric power generators.
Composting
- The controlled biological decomposition of organic material in the presence of air to form a humus- like material. Controlled methods of composting include mechanical mixing and aerating, ventilating the materials by dropping them through a vertical series of aerated chambers, or placing the compost in piles out in the open air and mixing it or turning it periodically. [Terms of Env]
Recycling
- The separation and collection of wastes, their subsequent transformation or remanufacture into usable or marketable products or materials, and the purchase of products made from recyclable materials.