The History of Geothermal Energy in America

The history of geothermal energy

Geothermal systems offer an efficient, low-carbon way to generate electricity and provide heating and cooling for homes. They use the naturally occurring heat in the rock and fluids in the Earth to accomplish their objective.

Today, we have numerous technologies that enable us to access geothermal energy. We have geothermal power plants and geothermal heat pumps. We also use the hot water in the Earth to heat buildings directly and for use in greenhouses, and some cities pump it underneath roadways to melt snow and ice.

These technologies were not the first use of geothermal energy, however. The history of the use of this resource in the United States stretches back many, many years.

Early history

People have been using this heat for various purposes for many years. The first use we know of dates back more than 10,000 years ago when the American Paleo-Indians used hot springs for cooking, cleaning, and bathing.

When European settlers arrived in America, they spent time at hot springs as well. In 1847, a surveyor named William Bell Elliot discovered a steaming valley north of present-day San Francisco. He called the area the Geysers — a misnomer.


The world’s first geothermal energy plant was built in Italy in 1904, and America got its first geothermal electricity generation plant several years later. In 1921, John D. Grant drilled a well at the Geysers in an effort to use them to generate electricity.

That project wasn’t successful, but another well he drilled a year later on the other side of the valley was. It became the United States’ first geothermal power plant. Using the steam from the first well, Grant built a second well and continued drilling more until the plant was generating 250 kilowatts of electricity. With the technology available at the time, however, the operation wasn't competitive with other energy sources and stopped being used.

1930 marked the first commercial use of geothermal energy for a greenhouse. That same year, Charles Lieb developed the first downhole heat exchanger and used it to heat his home. In 1946, Commonwealth Building in Portland, Oregon became the site of the first ground-source geothermal heat pump in the U.S.


The first large-scale geothermal plant for electricity generation began operating in 1960. The first turbine at the plant, located at the Geysers and operated by Pacific Gas and Electric, generated 11 megawatts of net power. It ran for more than 30 years.

Geothermal remained a minor contributor of energy until the ‘70s. The oil crises, which began in 1973, caused many utilities to start looking for alternative energy sources, which led to increased investment in alternative energy sources like geothermal. In the 1980s, geothermal heat pumps began to get popular because of their ability to reduce costs for heating and cooling.

The Geothermal Resources Council, which is based in Davis, California, also formed in the ‘70s to encourage the global development of geothermal resources. In 1972, the Geothermal Energy Association, the trade group for companies that deal with geothermal energy in the United States, was formed.

Modern day and the future

Since these early projects, geothermal energy in the United States has continued to expand. As of 2017, geothermal power plants in the U.S. generated approximately 16 billion kilowatt-hours (kWh), which is 0.4 of total U.S. utility-scale electricity generation. California produces 73 percent of the country’s geothermal energy.

Due to the efficiency and environmental benefits of geothermal, its use for heating and cooling and electricity will likely increase in the coming years. There may be a lot of history left to tell when it comes to geothermal energy in America.

Image credit: Geo Thermal, courtesy Flickr