It's Time We Looked Seriously at Geothermal Energy

Before his election as president, Joe Biden’s campaign issued an aggressive energy plan.  In addition to a large number of offshore wind projects, a key element, Biden’s pre-election platform promised an intense effort to develop and commercialize grid-scale energy storage at a fraction of the cost of lithium-ion batteries; small modular nuclear reactors (SMRs) at a fraction of the construction cost of utility-scale reactors; zero net-energy buildings at zero net cost; using renewables to produce carbon-free hydrogen at the cost of shale gas; and a vast expansion of electric vehicles including POVs as well as transit fleets. Several have made modest progress, some with the help of the US Department of Energy, focused on SMRs, and the private energy industry, which is aggressively exploring the use of hydrogen to co-fire with or replace natural gas in combustion turbines. If we're to make a meangingful dent in carbon emissions, and have even a chance to halt global warming, we're going to have to cut fossil-fuel generation and ramp up clean energy generation, many fold.

Now you may have noticed that is mid-2022, there’s a lot of excitement around offshore wind, perhaps with a slight lack of realism as to how long OSW projects may take to get permitted, financed, installed, interconnected, and operational. NIMBY opposition from coastal communities within viewscape of offshore turbines, as well as towns where transmission cables may need to come ashore, are genuine obstacles. Today we still have no utility-scale offshore wind parks in the United States other than the 30 megawatt, five-turbine Block Island park off the coast of Rhode Island. And many see Block Island as merely a demonstration project.

At the same time, we didn’t see, and to my knowledge still haven’t seen, a meaningful mention of geothermal energy by the Biden administration. Last Friday, by chance I heard a segment on geothermal on NPR, the first time I’ve heard a long-format discussion of this technology on radio. It reminded what a major missed opportunity this is. The 11-minute segment with Jamie Beard, founder and executive director of Project InnerSpace, focused on expanding the use of geothermal energy, is well worth a listen.  

Simply put, geothermal energy is a beneficial use of the heat generated at relatively-shallow depths underneath the earth’s crust. It’s an ideal and truly renewable energy source that can be used for heating and for generating electricity—because it’s abundant, reliable, predictable, and clean. And it can be leveraged easily under three conditions: heat, hot water or steam, and permeable rock. Geothermal power plants can operate efficiently for decades, and because of their reliability, can produce a constant flow of baseload power, assuming the amount of energy extracted is synchronized with the rate at which the underground rock is able to renew its heat. In fact, capacity factors are typically at least 80% and as high as 96%.

According to the US Energy Information Administration (EIA), The United States leads the world in the amount of geothermal electricity generation. In 2020, there were geothermal power plants in seven states—California, Nevada, Utah, Hawaii, Oregon, Idaho, and New Mexico. And yet that world-leading production added up to only 0.4% of total U.S. utility-scale electricity generation, with the vast majority in just California, with 70.5% of total US geothermal electricity generation, and Nevada with 24.5%. Geothermal is also an enormously underutilized form of energy globally; according to Solar Reviews, in 2020, geothermal power plants across the world currently deliver just 12.7 gigawatts of electricity, with installed geothermal heating capacity a bit higher at 28 GW. 

At the same time, Geothermal represents a very cost-effective way to generate electricity. According to the EIA in its 2020 Annual Energy Outlook, the estimated total levelized cost of electricity (LCOE, unweighted) of geothermal, among new dispatchable generation resources entering service in 2025 (with the tax credit)—including ultra-supercritical coal, combined cycle, combustion turbine, advanced nuclear, and biomass—is lowest. LCOE represents the average revenue per unit of electricity generated that would be required to recover the costs of building and operating a generating plant during an assumed financial life and duty cycle. Key inputs to calculating LCOE include capital costs, fuel costs, fixed and variable operations and maintenance (O&M) costs, financing costs, and an assumed utilization rate for each plant type.

Geothermal energy very friendly from an environmental point of view. While geothermal plants do emit greenhouse gases, the amounts are a tiny fraction of those from fossil-fueled plants. Moreover, there are no reported cases of water contamination from geothermal sites in the US, according to the Union of Concerned Scientists. This is not to be confused with fracking.

There are other opportunities under our feet from this renewable energy source directly under our feet. The US Department of Energy (DoE) says “Enhanced Geothermal Systems (EGS), also known as Engineered Geothermal Systems, hold the potential to power tens of millions of American homes and businesses.” While generating electricity via geothermal to the grid is limited to some specific geographical locations, EGS “requires improving the natural permeability of rock. Rocks are permeable due to minute fractures and pore spaces between mineral grains. Injected water is heated by contact with the rock and returns to the surface through production wells, as in naturally occurring hydrothermal systems. EGS are reservoirs created to improve the economics of resources without adequate water and/or permeability.”

Geothermal’s potential in the U.S. and worldwide is significant, even gargantuan. According to POWER Magazine, “(in) a report released in 2019 by the U.S. Department of Energy, geothermal electricity generation could increase more than 26-fold by 2050—reaching 60 GW of installed capacity.” The key, according to POWER, is advanced drilling techniques, and cites Quaise Energy, “a company working to develop enabling technologies needed to expand geothermal on a global scale, (which) claims as much as 30 TW of geothermal energy could be added around the world by 2050.”

What are we waiting for?