Spread out like a gigantic pool atop a cliff overlooking Lake Michigan is a pond of asphalt and clay containing enough water to generate electricity for 1.6 million homes.
It is part of the Ludington Pumped Storage Plant, which uses a simple technology: water is piped from a lower reservoir – the lake, in this case – to an upper reservoir and then released downstream by turbines oversized.
Proponents call these systems “the world’s largest batteries” because they contain large amounts of potential energy to be used when needed for the power grid.
The hydropower industry sees pumped storage as the best answer to a question that looms over the transition from fossil fuels to renewables in the face of climate change: where to get electricity when the sun is not shining or wind does not blow.
“I wish we could build 10 more. I love them,” Eric Gustad, community affairs manager for Consumers Energy, said during a tour of the Ludington facility.
But the Jackson, Michigan-based utility has no such plans. Environmental and logistical challenges and potential multi-billion costs led consumers to sell another potential site near the lake years ago. He is currently upgrading the existing plant with co-owner DTE Energy.
Building a new one “doesn’t make financial sense,” Gustad said. “Unless we get help from the state or the federal government, I don’t see that happening anytime soon.”
BLOCKED IN NEUTRAL
The company’s decision illustrates the challenges facing pumped storage in the United States, where these systems account for approximately 93% of utility-scale energy in reserve. While analysts forecast growing demand for energy storage, industry growth has lagged.
The country has 43 pumped storage facilities with a combined capacity of 22 gigawatts, the output of these many nuclear power plants. Yet only one small operation has been added since 1995 – and it’s unclear how many of the more than 90 planned can overcome the economic, regulatory and logistical hurdles that impose long delays.
Three projects have obtained licenses from the Federal Energy Regulatory Commission, but none are under construction. Developers of a long-planned facility in Oregon expect work to begin in 2023. A Montana company that got a license five years ago needs a utility to operate the plant and purchase its storage capacity before construction begins.
On the other hand, more than 60 are being built around the world, mainly in Europe, India, China and Japan.
“The licensing process is crazy,” complained Malcolm Woolf, president of the National Hydropower Association, at a January hearing of the Senate Energy and Natural Resources Committee, saying it involved too many people. agencies.
While FERC licenses new facilities and renews existing licenses, other federal, state and tribal offices have roles to play, spokeswoman Celeste Miller said. “Each project is unique. All of them have various issues specific to each case,” she said.
The industry is pushing for an investment tax credit similar to what solar and wind get. President Joe Biden’s Build Back Better plan includes tax relief but is stalled in Congress.
Pumped storage dates back to the early 1930s. But most systems were built decades later to store excess electricity from nuclear power plants and release it when needed.
The storage facilities also serve as a safety net in the event of sudden power outages. When a New England nuclear unit shut down in 2020, Woolf said, “Boston’s lights didn’t flicker” as two pumped storage stations provided backup power.
While nuclear, coal, and natural gas can operate continuously, wind and solar cannot, so the reserve power market is likely to grow. Models from the National Renewable Energy Laboratory show that storage capacity in the United States could increase fivefold by 2050.
“We’re going to bring hundreds of gigawatts of clean energy to the grid over the next few years and we need to be able to use that energy where and when it’s needed,” Energy Secretary Jennifer Granholm said last year.
LOCATION, LOCATION, LOCATION
Using computer mapping, Australian National University engineers have identified more than 600,000 “potentially feasible” pumped storage sites around the world – including 32,000 in the United States – that could store 100 times the energy needed to support a global renewable electricity grid.
But the study did not examine whether the sites would meet environmental or cultural protection standards or be commercially viable. Its website acknowledged that “many, if not most … may be inappropriate”.
Environmentalists are cold toward pumped storage because reservoirs are typically formed by hydroelectric dams, which block fish pathways, damage water quality and emit methane, a potent greenhouse gas. In addition, most plants continuously draw water from rivers.
But recent designs envision “closed-loop” systems that tap a surface or subsurface supply, then cycle that water repeatedly between reservoirs. Water would be added only to compensate for evaporation or leakage.
The Hydropower Reform Coalition, representing conservation groups, says it could support such projects in “very limited circumstances”.
Yet some are met with resistance, including the Goldendale energy storage project in Washington state. It would route water between two 60-acre (24.3-hectare) reservoirs on opposite sides of a hill.
The facility could power nearly 500,000 homes for up to 12 hours, according to Rye Development, spearheading the project. It is seeking a FERC license and is expected to go live in 2028, but still requires a state water quality permit.
Environmental groups fear it will harm wetlands and wildlife habitat, while tribes say the project would encroach on a sacred site.
“What are we willing to sacrifice to bring this technology online?” said Bridget Moran, associate director of American Rivers.
The developers say the project would include cleaning up the polluted area of the lower reservoir.
The US Department of Energy has launched a web-based tool to help developers find the best locations.
A recent Michigan Technological University study identified hundreds of abandoned US mines that could host a pumped reservoir, with upper reservoirs at or near surface and lower reservoirs below ground.
They are close enough to transmission and distribution infrastructure and solar and wind generation facilities, the report says.
“All of these holes in the ground are ready to go,” said study co-lead Roman Sidortsov, an associate professor of energy policy.
But while some disused mines might be better for the environment, a project in New York’s Essex County has stalled due to water pollution concerns.
A COMPETITIVE FUTURE
As the market for stored energy grows, new technologies are emerging.
Texas-based Quidnet Energy has developed a pumped-storage offshoot that forces water underground, traps it in the middle of rock layers, and releases it to power turbines. The company announced a project in March with the San Antonio Municipal Utility.
Energy Vault, a Swiss startup, has designed a crane powered by renewable energy to lift and stack 35-tonne bricks. When power is needed, the bricks are lowered by cables that spin a generator.
For now, batteries are the main competitor to pumped storage power plants, which can produce electricity for eight to 16 hours. Lithium-ion batteries typically last up to four hours, but longer-lasting batteries are in the works.
“Are we going to get to the point where an eight-hour battery is cheaper than a pumped-storage plant? That’s the billion-dollar question,” said Paul Denholm, an analyst at the National Renewable Energy Laboratory.
A 2016 Department of Energy report said the US grid has the potential for 36 gigawatts of new pumped storage capacity.
“We don’t think pumped storage is the be-all and end-all, but it’s a critical part of our storage future,” said Cameron Schilling, vice president of markets for the Hydropower Association. . “You can’t decarbonize the system without it.”
Follow John Flesher on Twitter: @JohnFlesher