Terms : Hide Images
| 7198223587 | solar energy | sunlight that is converted into usable renewable energy |  | 0 |
| 7198223588 | hydroelectric energy | renewable energy obtained from the movement of flowing water |  | 1 |
| 7198223589 | geothermal energy | renewable energy derived from the heat in the interior of the earth |  | 2 |
| 7198223590 | wind energy | renewable energy captured by transforming the motion of air into electrical energy using a turbine |  | 3 |
| 7198223591 | biomass energy | energy created through the burning of biological materials, such as wood |  | 4 |
| 7198223592 | tidal energy | renewable energy produced by the rise and fall of ocean levels; used to generate electricity |  | 5 |
| 7198223593 | energy conservation | the practice of finding ways to use less energy or to use energy more efficiently | 6 | |
| 7198223594 | efficiency | the percentage of energy that is actually used to perform work | 7 | |
| 7198223595 | insulation | building material that blocks heat transfer between air inside and the air outside |  | 8 |
| 7198223596 | renewable energy | a resource that has a theoretically unlimited supply and is not depleted when used by humans. |  | 9 |
| 7198223597 | nonrenewable energy | a source of energy that has a finite supply capable of being exhausted. | 10 | |
| 7198223598 | fossil fuels | coal, oil, natural gas, and other fuels that are ancient remains of plants and animals. |  | 11 |
