The word geothermal comes from the Greek words geo (earth) and therme (heat). So, geothermal energy is heat from within the earth. We can use the steam and hot water produced inside the earth to heat buildings or generate electricity. Geothermal energy is a renewable energy source because the water is replenished by rainfall and the heat is continuously produced inside the earth.The direct use of hot water as an energy source has been happening since ancient times. The Romans, Chinese, and Native Americans used hot mineral springs for bathing, cooking and heating. Today, many hot springs are still used for bathing, and many people believe the hot, mineral-rich waters have natural healing powers.After bathing, the most common direct use of geothermal energy is for heating buildings through district heating systems. Hot water near the earth’s surface can be piped directly into buildings and industries for heat. A district heating system provides heat for 95 percent of the buildings in Reykjavik, Iceland. Examples of other direct uses include: growing crops, and drying lumber, fruits, and vegetables.

GEOTHERMAL ENERGY AND THE ENVIRONMENT

GEOTHERMAL ENERGY

The environmental impact of geothermal energy depends on how it is being used.

- Direct use and heating applications have almost no negative impact on the environment.

- Geothermal power plants do not burn fuel to generate electricity, so their emission levels are very low. They release about 1 to 3 percent of the carbon dioxide emissions of a fossil fuel plant.
- Geothermal features in national parks, such as geysers and fumaroles in Yellowstone National Park, are protected by law, to prevent the land from being disturbed.