Geothermal Power Offers a Hot Hand Up

Geothermal power is available to all Earthlings, but finding the right spot for a full-scale electrical plant takes a long drill, a lot of money, and luck.

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When I decided to visit the Blundell Geothermal Plant in southwestern Utah, I realized I’d need to educate myself a bit about the goings on in the earth below my feet — far below, deep inside the planet.

Like a true humanities scholar, I turned to Jules Verne’s novel Journey to the Center of the Earth. (Only the real Verne could erase James Mason, Arlene Dahl, Pat Boone, and that ridiculous goose of the classic movie from my mind.) And so I left Wyoming for southwestern Utah with the monomaniacal Professor Lidenbrock along for the ride.

Rather than journeying as he did, by climbing down the vent of an inactive Icelandic volcano, I got on I-70 and headed for its western terminus, just north of Beaver. Utah’s I-70 takes the traveler along the longest stretch of that interstate with no services, where exits are for viewing scenery or for testing the brakes of potentially runaway trucks. At a point about 30 miles west of Green River, Utah, is the San Rafael Swell, a giant dome-shaped anticline of sandstone, shale, and limestone. Infrequent but powerful flash floods have eroded the sedimentary rocks into valleys, canyons, gorges, mesas and buttes – the very sort of scenery most of us picture when we think “Utah!” 

The Blundell plant is about 15 miles northeast of Milford. I followed directions emailed to me by Garth Larsen, plant manager in charge of operations. I thought I’d be able to throw the directions away and use the tall cooling towers and transmission lines I expected to see to guide me in. But none of these things was visible. Instead, I drove along a gravel road through Bureau of Land Management (BLM) desert, past a wind farm under development, and over some railroad tracks. The thin traffic became non-existent save for a water truck dampening the dusty gravel. I could not see the plant – only the Mineral Mountains, with Granite Peak rising 9,771 feet above sea level in the bright morning sun.

I was a few hundred yards away from the plant when the road curved toward the gated entrance and I could finally see the structure. Blundell’s cooling towers are not particularly tall and there was only one power line leading away from the plant toward town. The main buildings were painted a shade known as “BLM Desert Tan,” blending in with their rocky surroundings. The entrance gate was locked. I could only see a few vehicles in the parking area and no one out moving around. I’d been instructed to dial the phone number printed on the phone box and someone would let me let inside. I dialed the number. I got the answering machine. What would Professor Lidenbrock do?

I waited a few more minutes, dialed again, and much to my relief was greeted and let into the facility. Soon Rene (pronounced REEN) Andrews, Blundell’s operations supervisor, came out to greet me. Andrews is not a tall man but sturdy, one who looks like he’s taken good advantage of the Utah outdoors lifestyle. After outfitting me with hardhat, earplugs and safety glasses, he explained how the Blundell plant came to be located where it is.
 
The site lies on the Roosevelt Hot Springs Known Geothermal Resource Area (KGRA). There were once hot springs here, popular with settlers, miners and cattlemen who needed a place to wash up and relax. (Reportedly, there used to be a brothel here operated by a woman known as “Negro Mag.”) The surface hot springs had dried up by 1966 but on occasion steam still rises from the ground nearby.

The subterranean Roosevelt Hot Springs still contains plenty of water, at more than 500°F and a pressure of 500 pounds per square inch. This hydrothermal reservoir is relatively near the surface of the earth thanks to the Opal Dome fault and the one named after Negro Mag. According to geologists, earthquakes broke up the Tertiary granite and Precambrian metamorphic rock to allow the magma-heated water to get closer to the surface.

Julianne Couch
Electic power generated at the geothermal plant leaves Blundell on a single power line.

Blundell Unit 1 came online in 1984 as the first commercial geothermal plant in the U.S. outside California. It works through production wells that bring the high-pressure, heated water to the surface, what’s called a “single-flash” system. Wellhead separators are used to “flash” the geothermal fluid into liquid and vapor phases. The vapor phase, or steam fraction, is collected from the production wells and directed into the power plant at temperatures between 177 and 204°C (350 and 400°F). The steam turns a turbine in the ordinary way of power plants: the turbine fires the generator, which creates the electricity, transmitted out on a single high-power line toward Milford.

Until recently the liquid phase, sometimes called “geothermal brine,” was channeled back into the geothermal reservoir through gravity-fed injection wells. Blundell Unit 2 entered service in 2007, using the spent geothermal fluid from Unit 1 as a heat source. Blundell Unit 3, a dual-flash system south of Units 1 and 2, began development in 2007 and when finished should bring the overall net capacity of the Blundell complex to more than 60 megawatts. Currently, the plant produces 26 megawatts gross (23 megawatts net), which equals the energy that would be produced by burning roughly 300,000 barrels of oil annually.

From a large south facing window in the control room, Andrews pointed out one of the production wells and the separator. From the window we could also see out onto the tabletop-flat desert floor above the geothermal field. The sage brush and other vegetation was scorched from a wildfire that started on July 6, 2007. The sprawling fire, caused by lightning, burned through sage brush, cheat grass and pinion juniper. It pumped out so much thick smoke that two motorists died in resulting accidents on I-15. The fire burned nearly up to the front, motorized gate at Blundell. Andrews said that dedicated firefighters had kept the blaze from destroying the plant.

Another noteworthy feature of the geothermal field is that the actual ground is noticeably warmer than surrounding areas. When the winter snows come, which Andrews said commonly drift waist-high, wildlife and livestock come to the warm, green field to graze. When the snow melts, or when rain falls, the water seeps through the ground back into the super hot underground reservoir.
We left the conference room, donned our safety equipment and headed to see the electricity being generated from deep inside the earth. Perhaps Professor Lindenbrock was too much with me, but I was rather disappointed to look through the floor vents: instead of seeing 5,000 feet into the fire and brimstone of the earth’s crust, I saw instead some insulated pipes.

Once I began to understand what was happening inside those pipes, however, the exotic quality of geothermal power came back to me. The steam traveling through them had come from a pocket in the earth’s crust 5,000 below my feet. That’s almost as deep as Denver, the Mile-High City, is high.

Julianne Couch
Pipes bring steam from 5,000 underground into the Blundell plant, near Milford, Utah.

The earth’s crust varies from 5 to 25 miles deep, so the drill holes for this plant just crack the surface, so to speak. A well would have to be drilled about 1800 miles to get through the middle layer, the mantle. And to get to the edge of Earth’s liquid core would require another 1,380 miles of drilling. Not even Professor Lindenbrock could have imagined that.
 
Rene Andrews loaded me up in a van and showed me around Blundell Unit 1, Blundell Unit 2, and the site where Blundell Unit 3 is being developed. The whole facility felt about the size of a modest 9-hole golf course. The Blundell plant employs 23 full-time employees, all men except for one administrative assistant who manages the warehouse.

One of our stops was at the plant control room. Like most control rooms at power plants, the work appears to an outsider about as exciting as playing checkers with yourself in a mirror. Korte Young, who has worked at Blundell from the very early days, was on duty. Watching dials, switches and lights to make sure everything is working within “operating parameters” around the plant could only be exciting, I would think, when something minor needed attention.

The greatest difficulty in developing and operating a geothermal plant seems to be drilling these very deep wells. The heat of these underground springs varies and noxious hydrogen sulfide gas in the geothermal resource poses problems. Since one cannot know for sure whether a selected site will prove adequate for producing power, drilling can be an extremely risky proposition.  Millions of dollars can be spent to drill one well, which may or may not pan out. Andrews believes the federal assistance to help renewable energy development puts geothermal at a disadvantage. To discover whether a site is suitable for wind development, for example, you start by erecting an inexpensive meteorological tower to determine wind velocity. If the wind is not adequate, then you pull up stakes. But if a test well is dug for a geothermal plant and does not yield plentiful hot water, the developers must start over, millions of dollars later.

But it is those deep wells that re-inject water into the earth that make geothermal energy renewable, according to the Geothermal Energy Association (GEA). That group explains that geothermal is considered a renewable resource because “the heat emanating from the interior of the Earth is essentially limitless. The heat continuously flowing from the Earth’s interior, which travels primarily by conduction, is estimated to be equivalent to 42 million megawatts of power, and is expected to remain so for billions of years to come, ensuring an inexhaustible supply of energy.”

Julianne Couch
Blundell Unit 2 came on line last year. It uses the spent geothermal fluid from Unit 1 as a heat source.


The GEA says geothermal plants use 1 to 8 acres per megawatt, versus 5 to 10 acres per megawatt for nuclear operations and 19 acres per megawatt for coal-powered plants. Geothermal isn’t a thirsty form of power requiring vast reservoirs to cool its apparatus. Plants use an average 20 liters of freshwater per megawatt hour versus over 1000 liters per megawatt hour for nuclear, coal, or oil, according to the GEA. U.S. geothermal advocates also point out that we aren’t importing the earth’s heat from countries that do not like us, and we aren’t held hostage by pricing consortiums. As for safety, the plants are not likely to blow up or melt down. They don’t burn fuels which depend on the dug up chunks of mountain tops or the ground beneath our feet.

The GEA also touts the clean qualities of geothermal power. “Unlike fossil fuel power plants, no smoke is emitted from geothermal power plants, because no burning takes place; only steam is emitted from geothermal facilities,” they say. “Emissions of nitrous oxide, hydrogen sulfide, sulfur dioxide, particulate matter, and carbon dioxide are extremely low, especially when compared to fossil fuel emissions.” 

Unlike solar and wind plants, geothermal facilities provide base load power, meaning they operate consistently 24 hours a day, no matter the weather. Andrews adds that plant efficiency at Blundell is high. (Power-plant efficiency is a measurement of power retained between creation and delivery.) Efficiency at Blundell, Andrews says, is in the high 30 percent range. Wind power plants typically are less efficient, in the lower 30 percent range, he explained. And the geothermal plant is available to produce power about 95 percent of the time. Compare that, Andrews said, to the wind farm going in down the road.

A map of U.S. geothermal resources (note that western Utah is red hot).
   
Even with these advantages, there is a good reason that such as small percentage of U.S. energy comes from geothermal resources. Currently about seven percent of electricity in the U.S. comes from renewable sources, according to the Energy Information Administration, and geothermal makes up only five percent OF THAT seven percent. An initial problem is that not every location has relatively shallow geothermal resources near tectonic plates, like the Roosevelt Hot Springs. But the GEA reports that up to 3959.7 megawatts of new geothermal power plant capacity is currently under development in the United States. States with projects currently under consideration or development include Alaska, Arizona, California, Colorado, Florida, Hawaii, Idaho, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. 

Geothermal power doesn’t have to be confined to areas where volcanoes rise, where hot springs bubble, or where earthquake faults lurk. Many individuals heat their residences with hot water heat from the ground, using geothermal heat pumps. Anyone whose home is built on the earth might be able to drill a well and use the globe’s warmth to heat the air in their home and their household water, too.

As I headed back through the desert, mesa and canyons of Utah, pointing myself back to the high basin terrain of Wyoming, I thought I heard Professor Lidenbrock’s voice echoing through the San Rafael Swell. He was planning how to get out of the center of the earth alive even though he was surrounded by boiling lava and was completely lost. “The situation is virtually hopeless, but there exists a possibility of salvation, and it is that possibility which I am examining. If we may die at any moment, we may also at any moment be saved.”

Perhaps geothermal power, if not capable alone of saving us from a future energy crisis, can at least give us a hand up.

Julianne Couch lives in Laramie, Wyoming. Her story is based on work supported by the University of Wyoming School of Energy Resources through its Matching Grant Fund Program.

 

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