However, far more use is made of geothermal energy for direct heat.

I believe that it is important to include, for example, geothermal energy.

Geothermal energy uses hot water coming from deep in the earth.

Development of geothermal energy is a threat to some populations.

We've used natural geothermal energy in limited situations throughout history.

The county has produced geothermal energy and high quality mineral water for more than 150 years.

Like solar, the use of geothermal energy is only limited by technology and the associated costs.

In some cases the heat source is a nuclear reactor or geothermal energy.

The costs of geothermal energy have dropped substantially from the systems built in the 1970s.

Geothermal energy is utilized to heat the houses in the area.