Why geothermal energy is being viewed as a viable alternative to fossil fuels

President Biden and the European Union on Friday announced new plans to enable Europe to become less dependent on Russian oil and gas. But for now, the Russian invasion has opened up much larger questions over our dependence on fossil fuels and the need to develop cleaner renewable energy. Science correspondent Miles O'Brien reports on how and why geothermal energy is attracting new interest.

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  • Judy Woodruff:

    As we reported President Biden and the European Union today announced plans to enable Europe to become less dependent on Russian oil and gas, but those efforts will take a lot more money and time to execute.

    For now, the Russian invasion is raised much larger questions over our dependence on fossil fuels and the need to develop cleaner renewable energy.

    Science correspondent Miles O'Brien reports on why geothermal energy is attracting new interest.

  • Miles O’Brien:

    There's a lot of heat beneath our feet, and that's pretty obvious here, near the Salton Sea in California's Imperial Valley.

  • Billy Thomas, Berkshire Hathaway Energy:

    These are really world-renowned mud pots that occur naturally.

  • Miles O’Brien:

    Hot water and carbon dioxide create mini-volcanoes at the Davis-Schrimpf mud pots.

  • Billy Thomas:

    They just come up in different areas. They all go dormant and just come up somewhere else.

  • Miles O’Brien:

    They sit right in the middle of one of the largest geothermal generation fields in the world. It's renewable, sustainable and carbon-free, so exploring new ways to tap into this resource is now a very hot field.

    What are we seeing here?

  • Billy Thomas:

    So, here, we're looking at some of our production wells for the Region 1 facility.

  • Miles O’Brien:

    Billy Thomas is a senior geoscientist at Berkshire Hathaway's CalEnergy project. He showed me some of the 25 wells and 10 power plants which together generate 345 megawatts, enough to power more than 300,000 homes. But, he says, they are only scratching the subsurface.

  • Billy Thomas:

    This field is a perfect example of field that has a lot of potential. There's about 5,000 gallons per minute flowing through here.

  • Miles O’Brien:

    Geothermal heat comes from the molten core of our planet, which, at more than 10,000 degrees Fahrenheit, is as hot as the surface of the sun. As the heat radiates up, it gradually cools.

    Here, they drilled wells between 2,000 feet and two miles deep, where the temperature is only about 600 degrees Fahrenheit. Very salty, very hot water, called brine, along with steam, race upward. The steam spins turbines, producing electricity, and the brine is injected back into the ground, where it is reheated by the earth, replenishing the reservoir.

    Is this kind of managed well more or less infinitely sustainable?

  • Billy Thomas:

    So, yes, we have had the benefit here of actually operating for some of these fields up to 40 years, and we really have a very robust reservoir, where we don't see a lot of the decline. So we really have a good system set in place right now to really make this a sustainable renewable baseload energy.

  • Miles O’Brien:

    Baseload, meaning 24/7/365, steady production that wind and solar cannot provide. Geothermal is an emerging dark horse in the race to a stable zero-carbon electrical grid,

  • Amanda Kolker, National Renewable Energy Laboratory:

    The last couple of decades have seen about a 25 percent growth worldwide.

  • Miles O’Brien:

    Geologist Amanda Kolker is program manager for geothermal technologies at the National Renewable Energy Laboratory in Golden, Colorado.

  • Amanda Kolker:

    The technology that we're using today really hasn't changed substantially. There have been little, incremental kind of optimization improvements.

    It's a really exciting time, because we are getting a lot more, I think, innovative ideas in the geothermal sector than we have for decades.

  • Jim Turner, Controlled Thermal Resources:

    So this area is highly fractured underneath.

  • Miles O’Brien:

    One of the surprising innovations, geothermal wells can also be a great source of minerals.

  • Jim Turner:

    So, we just drilled two wells.

  • Miles O’Brien:

    Jim Turner is chief operating officer of the U.S. division of Australia-based Controlled Thermal Resources. He walked me through the 50-megawatt geothermal power plant the company is building in the Imperial Valley.

    The salty brine rising from the wells contains almost the entire periodic table of elements, and Turner says the rocketing demand for electric cars has made it profitable to extract and sell lithium.

    Do you have any projections on how much lithium you might be able to produce?

  • Jim Turner:

    We will produce about 20,000 metric tons a year of lithium product.

  • Miles O’Brien:

    That would be about 8 percent of the current global production, four times more than the U.S. provides today.

    That's a nice bonus, isn't it?

  • Jim Turner:

    It is. It is a very good bonus. In the past, it just didn't have enough value to warrant the cost of money to develop, build a plant and operate it to be able to sell the lithium compounds.

  • Miles O’Brien:

    The rock beneath is naturally fractured and permeable. This is the end of the famous San Andreas Fault.

  • Amanda Kolker:

    The types of resources that you need to produce power are not available everywhere within drillable depths. It's just, at this stage, not economic to produce steam from extremely deep wells.

  • Miles O’Brien:

    But that could be changing at the FORGE project in Utah. Here, the Department of Energy is piloting a technique called Enhanced Geothermal Systems, or EGS.

    The plan is to drill two deep wells into low-permeable hot rock, fracture the rock in between the wells to create a reservoir, and then pump water into the cracks. It returns to the surface piping hot. The notion is making for some strange bedfellows. Oil and gas industry veterans are now drilling for hot rock, instead of black gold.

  • Cindy Taff, COO, Sage Geosystems:

    What we want to prove is a single well EGS system.

  • Miles O’Brien:

    Petroleum engineer Cindy Taff is a 35-year veteran of the oil business. Now she is chief operating officer of Houston-based Sage Geosystems.

    The company is hoping to reduce the cost of EGS. Near McAllen, Texas, they are testing a single well alternative for harvesting heat from hot dry rock. They drill down and then horizontally, from here fracturing the sedimentary rock in between. Cold water is pumped down through the cracks. Now hot enough to generate power, the water heads up to the turbine in a concentric pipe in the very same well.

  • Cindy Taff:

    The oil and gas industry has fracked in sedimentary rock for years, and we know how to mitigate induced seismicity. And, quite frankly, the rock is so soft, you usually don't get to induced seismicity in sedimentary rock.

  • Miles O’Brien:

    Still, the well is ringed by seismic monitoring sites. Geothermal fracking has triggered earthquakes in the past. This one in South Korea in 2017 made news, causing 135 injuries.

  • Amanda Kolker:

    We don't need stimulation for most geothermal. Where we do, do stimulation, I think we can be smart about avoiding zones of seismic risk.

  • Miles O’Brien:

    The shale fracking boom has driven a lot of innovation in the drilling business. In Houston, a small company called Particle Drilling is partnering with a big player, NOV, to help push drilling technology into a geothermal era.

    The bit they are developing fires 12 million ball bearings a minute out of four nozzles.

    Jim Schiller is CEO of Particle.

  • John Schiller, CEO, Particle Drilling:

    It obliterates the rock. What you get out are some very fine cuttings and every once in a while a bigger piece.

    What we envision was always a three-to-five-time improvement. As we have combined our bits between NOV and Particle and all, we're seeing that.

  • Miles O’Brien:

    Tony Pink is Chief Technology Officer of the Wellbore Technologies segment of NOV. He says it costs about $100,000 a day to run a typical drilling rig.

  • Tony Pink, Chief Technology Officer, NOV:

    We're at that tipping point now. And so, if we take the particle drilling technology or drill bit technology and make that jump from 60 foot an hour to 80 to 100, then we move that economic needle that you get geothermal anywhere.

  • Miles O’Brien:

    Geothermal anywhere, it's an enticing prospect. The path to zero carbon may well take us on a journey toward the center of the Earth.

    For the "PBS NewsHour," I'm Miles O'Brien in Houston.

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