Geothermal energy is created by the heat of the earth. It generates reliable power and emits almost no greenhouse gases.
This is how it works: When groundwater seeps below the earth's surface near a dormant volcano, the water is heated by reservoirs of molten rock, usually at depths of up to 9,800 feet (3,000 m). Wells similar to those used to produce crude oil and natural gas are drilled to recover the water. Once captured, steam and hot water are separated. The steam is cleaned and sent to the power plant. The separated water is returned to the reservoir, where it helps to regenerate the steam source.
Very few places provide the special conditions needed to generate geothermal energy. At these locations, deep fractures in the earth's crust allow the molten rock to surge close enough to the surface to heat water underground.
What Are the Benefits?
In addition to providing clean, renewable power, geothermal energy has significant environmental advantages. Geothermal emissions contain few chemical pollutants and little waste—they consist mostly of water, which is reinjected into the ground.
Geothermal energy is a reliable source of power that can reduce the need for imported fuels for power generation. It's also renewable because it is based on a practically limitless resource—natural heat within the earth.
The electricity produced by our geothermal power operations is sold to local power grids, providing clean energy to fuel the growth of some of the world's most rapidly expanding economies.
What Chevron Is Doing
Chevron is one of the world's leading producers of geothermal energy.
Chevron began geothermal operations during the 1960s by pioneering the development of the Geysers, north of San Francisco, California. In the 1970s, two discoveries in the Philippines led to the development of the Tiwi and Makiling-Banahaw (Mak-Ban) geothermal projects on Luzon. We discovered the Salak and Darajat fields on Java in Indonesia in the 1980s and began commercial production in the 1990s.
Chevron's geothermal interests in Indonesia and the Philippines produce enough renewable geothermal energy to support millions of people in those countries.
In Indonesia, Chevron operates the Darajat and Salak fields, which have a combined operating capacity of 647 megawatts.
Chevron also has a 40 percent interest in the Philippine Geothermal Production Company, Inc., the operator of the Tiwi geothermal facility in Albay Province and the Mak-Ban geothermal facility in Laguna and Batangas provinces. These fields provide steam to the third-party Tiwi and Mak-Ban geothermal power plants in southern Luzon. These plants have a combined generating capacity of 692 megawatts.
We are assessing prospects in both countries that could lead to more geothermal energy production.
Geothermal resources represent significant untapped energy. As Chevron continues to pursue geothermal opportunities, we are at the forefront of bringing this clean, renewable energy to our communities.
Updated: May 2015