Back to Earth

Wendy Calvin is the new director of the Great Basin Geothermal Center. She formerly worked with NASA’s Mars missions, studying where water may have met land on that planet. Now she’s looking at where water and land interact closer to home.

What kind of potential does Nevada have for geothermal energy compared to other places?

Geothermal in Nevada, I think, could be huge. In terms of the total number of megawatts, we have active plants that are delivering in—I don’t know the precise number, but some estimates suggest we could have 10 times our current value. And that’s just because of where Nevada is and the local geologic setting, and the crust in Nevada is thin. That brings hot water to the surface, so we can use that to heat buildings. They dry onions out at the Brady plant.

They do what?

They use the heat to directly dry onions. … But I think power production and electricity generation is probably the biggest application. Most states have Renewable Energy Portfolios, where they’re promising to put so much green energy online five or 10 years from now. So the greatest use of that is to use hot water in that way, then use turbines, and that generates electricity.

What obstacles are there to making Nevada a leader in geothermal energy?

I think, through the history of the Great Basin, we have a pretty good sense of the likely resources. I think one of the biggest hurdles and challenges is picking a place to drill … you have to drill and come up with hot water, and it has to be a specific temperature in order to have the heat exchange to generate electricity. There’s a lot of research going on to find how to do better energy generation from lower temperature systems and better exploration approaches. … It’s fairly well understood how oil and gas is trapped, but in some ways, the geothermal exploration industry is where oil and gas was 80 or 60 years ago.

How does geothermal drilling differ from drilling for oil and gas?

You’re not consuming the hot water you’re pulling out of the ground. You bring it to the surface, run it through a heat exchanger and through a turbine. … In oil and gas, you’re extracting something that you’re going to use and burn and never get back. It’s going to put CO2 in the atmosphere. In geothermal, you’re basically taking the heat out of it, using that to run turbines, which generates electricity, and the water you take out goes back into the ground. So it’s kind of a recycling process. You’re mining the heat instead of the water. … And geothermal is really low in CO2. You’re not burning any fossil fuels to generate electricity, so it has a low carbon footprint and a low spatial footprint. You don’t need acres and acres of land for a geothermal plant. … It has a very small physical footprint to generate the same amount of energy as solar or wind.

Why are you interested in this kind of work?

What I do is exploration, exploring the solar system and figuring out what’s out there. What I wanted to do was come back to Earth and do something a little closer to home. So the exploration was to find out good spots for geothermal resources. So I’m interested in exploration and finding new things. And the rock and water interactions [on Mars] naturally led to looking at earth and rock and water interactions. The thing that’s interesting here is the geothermal portion of that. …

That reminds me, there are some new geothermal programs at UNR.

We have the National Geothermal Academy. They were calling it an “institute,” but we’re calling it an academy now. … We’ll be doing a number of summer, one-week sessions that feed into our renewable energy minor … things that are specifically about geothermal but link into bigger programs.