It’s the kind of thing that’s “hiding in plain sight.” Most renewable-energy sources are so obvious and abundant, they're almost invisible. But go outside on a sunny day, and it’s easy to feel a lot of energy streaming down from the sun. Same thing on a blustery day, when the potential power is made apparent by the bending trees.
Entrepreneurs are racing to tap both wind and solar energies as fossil fuels become ever more difficult to find and the atmosphere warms from burning them. But no matter where you go, the most abundant, clean, constant, renewable energy of all is never more than just a couple of miles away ... straight down.
It would be about a 4,000-mile trip to the center of this planet, but barely scratch the surface and things already begin to heat up. In fact, many mines are limited in depth because temperatures become too high for humans to work in. At the earth’s core is a huge mass of molten iron and nickel that may reach as high as 12,000 degrees. Things cool closer to the surface, but the crust’s shifting tectonic plates also generate intense heat as they push and rub against each other.
Especially near fault lines in the western half of the continent, temperatures reach extreme levels at only a few thousand feet below the surface, and ground-water that flows down through fissures becomes superheated under intense pressure. If that geologically heated water makes its way back to the surface, it appears in hot springs, and the heat it carries with it is known as geothermal energy.
But, there are places where a vast amount of geothermal heat rises fairly close to the surface and is relatively easy to reach, transform into electricity and pump into the power grid for transmission to urban centers. A high number of such hot spots exist right here in Utah—second only to Nevada in discovered geothermal resources. The central Intermountain West (including Wyoming and Colorado) is often described as the “Saudi Arabia of geothermal energy.” And Utah has the added advantage of not only having an abundant supply of geothermal, but its geothermal resources are located on land where ample moving air could drive wind farms and regular sunshine could power solar facilities.
These thrice-blessed regions are also near existing power transmission lines, allowing all three types of renewable energy to get plugged into the grid at about the same point, an advantage similar zones in Nevada don’t share. In a word, Utah’s renewable power potential is almost ideal, and at least one company is going after it in a big way.
I had no idea of Utah’s abundance of geothermal energy before meeting David West at a party. He’s the marketing vice president of the Provo-based Raser Technologies.
Besides designing advanced electric powertrains for vehicles (you may spot Raser’s red, experimental H3 Hummer on the road sporting the number “100,” meaning 100 miles per gallon), the company’s main activity is developing geothermal energy. And Raser’s flagship project is closer to coming to market than are its automotive electric motors, transmissions and controllers. In fact, West says, Raser has already been supplying Anaheim, Calif., with green energy for more than a year.
A growing slice of Disneyland’s power now comes from an unlikely place. Several miles outside the hamlet of Minersville, Utah—west of Beaver, Utah—in the middle of some of the sparsest, driest, most wind-blown terrain in the state, sits Raser’s first operational geothermal generating plant in Thermo.
It’s not some monster that can be seen for miles spewing fumes into the air. It’s a low-profile facility with structures that aren’t much taller than those of its only neighbor: Circle 4 Farms produces more than a million pigs for slaughter every year in compounds that appear in the distance across the barren landscape. The overpowering odor coming from massive manmade lagoons of hog excrement and urine are an extra reminder that no one wants to live in this place, where conditions don’t allow anything to grow more than 2 feet above the desert floor
But here’s where Raser struck gold—superheated water, really—and it’s relatively close to the surface. A little more than a mile down, Raser’s drills hit fairly hot water under high pressure that makes its way to the surface without much encouragement. It’s run through a heat exchanger (think of something akin to a car radiator) where the heat is transferred into an organic, nontoxic liquid that flashes into steam and spins a series of 50 SUV-size generating turbines.
The company claims this “binary” system, developed in conjunction with United Technologies, offers several advantages over older “flash” systems, in which turbines are driven directly by steam from the mineral-laden groundwater that’s corrosive to metal components. These smaller units are easier to build than a typical geothermal plant that uses a single large generator. One of those can take five to seven years to develop, while a modular plant like Raser’s can be brought on line in about two years.
West is enthused because advancements in generator technology during the past two years have seen advancements in performance equivalent to those in computers. Since Raser brought its first generators on line, improvements have boosted efficiency by 30 percent and output has tripled, and he anticipates five-fold increases in those numbers in the near future.
He claims that the “brown vs. green” energy competition soon will be won by geothermal without factoring in the “externalized” expenses that fossil-fuel power generation gets away without paying for, especially the environmental and human costs of pollution.
The biggest improvement, West says, is that its newer equipment can use water at temperatures of less than 250 degrees, as opposed to the 300 to 600 degrees previously needed. That means that vast geothermal resources that could not be utilized previously can now be tapped.