Carbon sequestration the technology of capturing carbon dioxide emissions from power plants and storing them will be neither easy nor inexpensive, finds new research at the University of Nevada, Reno.
But the studies find that the costs may be so high adding as much as 65 percent to the price of power produced at coal-fired plants that some technologies that otherwise might not make sense become economically feasible, a researcher said.
The findings are important to northern Nevada as Sierra Pacific Resources plans its Ely Energy Center, a 1,500-megawatt coal-fired generating plant near the Utah border.
The Reno-based utility has agreed with regulators to design the plant so that carbon sequestration technology can be installed when it's commercially feasible, and the company is looking at technologies to capture and store carbon dioxide produced by burning coal.
Carbon dioxide pollution is linked to global warming.
Sierra Pacific Resources is participating in several studies of ways to capture carbon dioxide emissions and store them so they don't enter the atmosphere, says Starla Lacy, director of environmental affairs for the utility.
And the company has looked at some new ideas, such as a concept by UNR researchers to feed carbon dioxide to algae, then harvest the algae to produce biodiesel.
"We recognize that some sort of carbon regulation is coming," she says, noting that Sierra Pacific doesn't believe it can meet the needs of its customers exclusively from renewable resources.
The Nevada Bureau of Mines and Geology at UNR, working under contract with the U.S. Department of Energy, found that some of commonly discussed ways to storing carbon dioxide will be challenging in Nevada.
One possible strategy calls for carbon dioxide to be pumped into underground oil reservoirs, where it could be stored for centuries. An additional benefit, proponents say, is that the carbon dioxide would force difficult-to-pump oil reserves to the surface.
The problem in Nevada, however, is that there aren't enough oil fields to provide much space for storage of carbon dioxide, says Jonathan Price, state geologist and director of the Bureau of Mines and Geology.
Another possibility that's kicked around is injection of carbon dioxide into salty aquifers deep below the earth's surface.
The UNR researchers found few locations in the state that would be suitable for that technology. Besides, they noted that current state law appears to ban injections into aquifers.
A third possible technology, which Price acknowledged to be years away from perfection, would use some of the state's ample supplies of basalt to create a chemical reaction with carbon dioxide.
That process exists in nature although much more slowly and would permanently lock up carbon dioxide after the chemical reaction.
Among the challenges to be overcome, Price said, is the fact that that big volumes of basalt would need to be mined think of projects the size of some of the state's large surface gold mines. And the mineral that's created by the chemical reaction has about a 30 percent greater volume, meaning that it would more than fill the giant holes dug to mine basalt in the first place.
Because so much basalt would be needed, the UNR researchers said it would make more sense to locate power plants near rock mines rather than transport mined rock to the site of a power plant.
A California Energy Commission study last year estimated that the cost of capturing carbon dioxide at coal-fired plants might boost the cost of electricity produced by the plants by nearly two-thirds.
While those higher prices would be bad news for power consumers, they also would allow use of technologies that currently aren't economically feasible, Price said.
Sierra Pacific Resources, however, has emphasized that economics and keeping electricity affordable are critical pieces of its thinking about carbon sequestration.
And the company's executives have said that the utility is committed to use of coal-fired generation because they don't believe that renewable sources of electricity can meet all the demands of the fast-growing state.
