From Hot Dry Rock to EGS: Geothermal Innovation and The Importance of Domestic Development
Enhanced Geothermal Systems (EGS) are on the forefront of international renewable energy development. But the technology, at its core, is not as young as some might imagine. The seeds of what we now call EGS were first planted in the 1970s, and they’ve grown significantly since then. With sufficient support, EGS is poised to markedly alter the United States’ relationship with renewable and nonrenewable energy sources.
Traditional Geothermal Energy
Humans have utilized the earth’s internal heat for thousands of years, at first only for bathing in hot spring-fed pools. By the late 19th century, geothermal heat was warming occasional greenhouses and homes. It wasn’t until 1904 that the heat was first harnessed for power (it lit five light bulbs) and 1911 that the first power plant was built in Larderello, a city in southern Tuscany, Italy. As demand for electricity grew throughout the rest of the twentieth century, geothermal energy came to account for a growing, if relatively small, portion of the world’s energy supply. In the United States today, there is almost 3100 megawatts of geothermal generating capacity on line, with more than 7000 megawatts in development.
For traditional geothermal energy to be generated at a potential site, two elements must be present: heat and water. Heat, in the form of hot bedrock, can be found in many places throughout the United States. But accessible water is harder to come by. Water must be located in reservoirs within the hot rock, and in order for its heat to be harnessed for power, the water must be able to flow freely through open and connected fractures in the rock. This has been the primary limiter of geothermal energy’s growth.
EGS/Hot Dry Rock Genesis and Development
As long as oil was easy to come by, there was no major public push to pursue alternative energy sources. But the 1970s oil crisis cast a more realistic light on the increasingly imported fuel. It came with political strings attached and forced the United States to depend on foreign nations. The U.S. began to look for renewable, reliable alternatives to fossil fuels. It was then that the beginnings of Enhanced Geothermal Systems took root, although at that time it was called Hot Dry Rock.
Researchers at the Los Alamos National Laboratory in New Mexico asked a simple question: If energy requires heat plus water, could we mimic the naturally occurring reservoirs by pumping water through existing hot rock and back out again? After creating a network of tiny fractures throughout the rock, the same water could then be pumped through a closed circuit, potentially providing years of power generation.
In 1973, the first Hot Dry Rock (HDR) experiments began at Fenton Hill, near Los Alamos. The initial experiments were promising and set in motion international interest in the concept. Throughout the 1970s Germany, Japan, the United Kingdom, and France started exploring the feasibility of HDR within their own borders. Australia and Switzerland soon joined, too. Over the next 25 years, international teams worked to develop appropriate drilling and reservoir stimulation practices for specific local conditions, exploring increasingly more refined technology to create geothermal reservoirs.
Though the United States pioneered this new branch of renewable energy with the Fenton Hill project, the greatest push for EGS development today is overseas. Currently, the world’s largest EGS project is in Australia’s Cooper Basin. Germany, even with a limited number of appropriate sites, is nonetheless one of the world’s leading EGS developers. Japan, France, and the UK also have EGS projects either in development or in operation.
EGS offers an environmentally sustainable, politically independent, and economically viable source of energy. A significant portion of the U.S. public is interested in developing a renewable energy infrastructure. But without also developing the technology to enable that infrastructure, the U.S. will miss out on many of the benefits it offers.
The Newberry EGS Demonstration in Bend, Oregon, is exactly the type of technology demonstration necessary to keep the United States relevant, competitive, and self-sufficient in the context of both renewable energy and energy as a whole. Through the work of companies like Davenport Newberry and AltaRock Energy, EGS has the potential to provide as much as 10 percent of the nation’s energy needs within the course of a generation—and to do so using not only domestic renewable resources, but domestic technology as well.