Compared to solar and wind, geothermal energy is still a small fraction of the renewable energy market. It’s holding its own, however, and it’s likely to become a much bigger player in the not-so-distant future.
“The resource is enormous,” Karl Gawell, executive director of the Geothermal Energy Association (GEA), told the E-Commerce Times. “We’re looking for how to solve our energy problems, and this is a huge resource we’re only starting to tap.”
Geothermal energy is based on a primary fact about the earth: It’s hot at the core. The farther you drill down, the hotter things get. This heat energy can be used to create electricity, primarily by accessing water that is heated by rock layers far below the surface. This hot water is then used to turn turbines to create power.
Older geothermal plants relied on very hot water — around 300 degrees Fahrenheit — which is generated in regions with hot rocks relatively close to the surface, particularly those located along active tectonic faults. For this reason, the first geothermal plants in the U.S. were located in Hawaii, Utah, Nevada and California.
Newer geothermal technology, however, allows for what are called “binary power plants.” These can be located in regions with water that is not nearly as hot — usually less than boiling, or just around 100 degrees. Binary plants bring up this medium-hot water, which stays in pipes that run against a heat exchange, which in turn heats a chemical fluid with a much lower boiling point. This heat-activated fluid then turns the turbines, and the water is sent, uncontaminated, back into the earth.
“These plants can be built anywhere there is hot-enough rock,” explained Gawell.
There has, in fact, been something of a boom in the geothermal industry, based on this new technology. Whereas in 2005 there were only four states with active geothermal plants, now there are nine — and 16 more have plants under development, including Louisiana, Texas and Mississippi.
There is ongoing geothermal research, both in the U.S. and worldwide, and this research is leading to other applications and ways of using the heat from the earth. In addition to using the hot water or heated liquid to turn turbines, there is a growing trend toward “direct use” geothermal, which uses hot water from the earth to provide heat, particularly for commercial buildings.
An even newer technology under development, called “enhanced geothermal,” involves pumping water into the ground to be heated. All of this research and development promises to lead to even more geothermal power production in the future.
These new technologies and plants have begun to generate more jobs in the field. In 2008, the GEA reported about 18,000 employed in the industry in the U.S. That number is now around 25,000, Gawell estimated — still relatively small, but continuing to grow despite tough economic times. These jobs include work for designers, architects, geologists, construction workers, mechanics and many others.
“The jobs in this industry are definitely going to grow,” Gawell predicted. “There are a lot of projects in the future. We’ve got this investment in technology that will pay off in the next several years.”
Those that work in the industry, in fact, have confidence in energy that comes from the earth — and its potential for becoming a much bigger player in the energy market.
“I’ve been doing this for 30 years, and I’ve never missed a house payment,” said Bill Rickard, president of California’s Geothermal Resource Group, which specializes in drilling geothermal wells.
In addition to all those new jobs, geothermal energy just makes plain environmental sense.
“The benefits [of geothermal] are many and obvious,” renewable energy consultant Fred Feige told the E-Commerce Times. “There are no fuel costs. There are few C02 emissions, except a small amount during construction. If the system produces steam, it is usually condensed, and the water is re-injected into the ground. The economic benefits will improve as the technology grows.”
Heating and Cooling
The other realm of the geothermal industry that has seen significant growth in recent years is the use of geothermal HVAC systems, or ground source heat pumps, for heating and cooling both residential and commercial buildings.
These systems are based on the fact that the earth’s temperature not far below the surface is relatively steady, in any climate, throughout the year. They’re not technically “geothermal,” in the sense of using heat coming from the earth — since the heat in this instance comes from the sun and is stored in the surface of the earth. Still, they merit mention in any discussion of earth-based, renewable energy systems.
In ground source HVAC systems, loops are sent down into the ground that are then used to regulate the temperature of a building. These systems cost much more to install than traditional electric heat pumps — as much as three times more — but they eventually pay for themselves, since they offer electricity savings of one half to two-thirds when compared to regular heat pumps.
Increasingly, ground source heat pump businesses are springing up around the country, and like geothermal energy production, this industry promises to create new jobs in the coming decades.
“The market is expanding at a remarkable rate,” Jay Egg, a renewable energy expert and owner of Egg Commercial Systems, told the E-Commerce Times. “We expect annual sales to double in the next four years to more than 400,000 units per year.”
And though it’s still a relatively small piece of the residential and commercial renewable energy pie, geothermal heating and cooling has its own particular advantages.
“Wind and solar are good, but they are dependant upon the climatic conditions,” explained Egg. “Geothermal heating and air conditioning works 100 percent of the time, reducing energy consumption by about 50 percent or more. There is no other claim such as this.”