A Seattle startup is seeking to revolutionize geothermal energy by tapping the heat of undersea volcanoes. In September, a 100-kilowatt geothermal generator will be deployed to the seafloor off the coast of Oregon, where a hydrothermal vent emits temperatures of up to 750 degrees Fahrenheit. The pilot project — the fifth of its kind — will continue to test the viability of converting that heat into commercially competitive, round-the-clock, and completely emissions-free electricity. One hundred kilowatts is modest by power plant standards — roughly enough electricity for dozens of homes — but the pilot is meant to demonstrate that seafloor hardware can operate dependably, a prerequisite for anything larger.

The team at Endurance Energy, the company behind the project, believes the technology could one day sustainably power entire cities. "Addressing the clean power problem is a way to make significant, scalable impact," founder and CEO Andrew Redd said in remarks recently quoted by GeekWire. "It's a fundamental of human life — people need power."

Geothermal has drawn increased attention in recent years for its potential to provide baseload clean energy. Unlike wind and solar power, geothermal is neither variable nor intermittent, meaning it can produce electricity at any time of day and match output with demand. It is also one of a very small number of clean energy sources that continues to enjoy broad bipartisan support, making it especially attractive to investors who might otherwise be deterred from clean energy portfolios in the current policy climate.

The challenge is that geothermal energy has historically been viable only in rare geographies where heat from the Earth's core escapes to the surface, such as geysers — or in underwater volcanoes, if generators can be successfully installed there. Undersea vents are among the hottest geothermal resources known, releasing fluids hotter than the reservoirs that feed most conventional land-based geothermal plants, which is part of what makes them both attractive and difficult to exploit. The concept is not new: companies and researchers around the globe have been examining the possibility for years. But a new groundswell of interest and investment could push the technology over the edge from scientific inquiry to commercial reality.

Other emerging geothermal technologies are turning away from natural thermal vents and toward creating their own. While underwater volcanoes could someday supply critical clean energy resources to coastal cities, their utility is geographically limited. In recent years, however, advanced drilling techniques borrowed from the fossil fuels industry have allowed geothermal companies to drill deep into the Earth and tap the heat radiating from the planet's core nearly anywhere on its surface. These "enhanced geothermal" projects have quickly become the new face of geothermal energy, though they still have a long way to go before becoming commercially competitive.

In almost all cases, underwater geothermal development will be more costly than onshore development. Those costs reflect genuine engineering hurdles: corrosive saltwater, crushing pressures at depth, and the need to carry the electricity back to shore through undersea cables. Marine-based projects do, however, offer certain benefits thanks to their out-of-the-way locations. Land competition and a not-in-my-backyard mentality have become a major bottleneck for clean energy projects in the United States, and building offshore and out of sight could therefore be a significant boon to getting projects approved.

Both underwater and enhanced geothermal energy remain in early stages of development, but they stand on the precipice of major growth. While geothermal is still a nascent industry in the United States — it supplies well under 1 percent of the country's electricity today, with the vast majority of installed capacity concentrated in California and Nevada — its benefits and potential scalability have become increasingly attractive to public and private interests alike. The federal government has provided a major leg up for geothermal projects as a way to diversify the domestic energy mix without turning to international supply chains. The United States Department of Energy estimates that enhanced geothermal technologies could power 65 million homes across the country by midcentury, and it has separately set a goal of cutting the cost of enhanced geothermal power by 90 percent by 2035.

The private sector, driven by big tech, is also eyeing geothermal to meet its own energy needs; Google, for example, has already signed an agreement to buy power from an enhanced geothermal project in Nevada. Skyrocketing energy demand projections fueled by the artificial intelligence boom are boosting investment from Wall Street and especially Silicon Valley. A recent report from Rhodium Group, a New York-based research firm and think tank, finds that geothermal alone could meet up to 64 percent of the expected growth in data center energy demand as soon as the early 2030s, provided the sector is rapidly scaled up and out.

By Charles Kennedy for Oilprice.com