Energy From the Earths Heat

Humans have long enjoyed bathing in natural hot springs, with waters warmed deep underground. But the heat generated within our planet—geothermal power—can do so much more. Geothermal plants use steam released from hot springs and geysers to turn turbines, creating electricity. In new, enhanced geothermal systems, engineers drill down to hot spots underground—around 200°C (about 400°F)—and inject water themselves, capturing steam as it is released.

Geothermal power is...

• consistent.
  Earth's interior is always hot, so geothermal power plants can provide a constant supply of electricity.
• accessible.
  Geothermal power plants no longer need to be located where there are natural geysers and hot springs: for new enhanced geothermal plants, engineers can drill deep into the ground in many places to tap into Earth's heat.
• light on CO₂.
  Compared with coal-fired power plants, geothermal plants release less than 1 percent of the CO₂ for the same amount of electricity.
• expensive.
  Electricity from enhanced geothermal power plants is currently expensive. Experts predict that if enhanced geothermal plants catch on, the price will fast approach that of coal-powered electricity.
• dirty.
  Although CO₂ emissions from geothermal plants are small, water use, water pollution and the release of air pollutants can be problematic.

5% of U.S. electricity needs could be met by geothermal power

According to some experts, enhanced geothermal power plants may provide the United States with about 5 percent of its electricity by 2050.

Heat From Below

Iceland is home to many volcanoes and geysers. So it's no surprise that the country depends on the reliable warmth bubbling up to the surface: 90 percent of Icelandic homes are heated by geothermal power.