The new American Energy Dominance plan articulated by US President Donald Trump has been excoriated as a gift to fossil energy stakeholders. However, some Trojan Horse elements are corraled within its clauses. The new plan also stipulates federal support for the expansion of the US hydropower industry, and a massive new pumped storage facility proposed for New Mexico is about to put that commitment to the test.
The Pumped Storage Solution
For all the attention lavished on lithium-ion battery technology, the fact is that good old fashioned pumped storage hydropower still accounts for the overwhelming majority of grid scale, long duration energy storage in the US. That’s overwhelming as in 96% as of last year.
The basic concept behind pumped storage is fairly straightforward. Take some water from a lower elevation and pump it upwards to a reservoir at a higher elevation when excess power is available. When demand rises, release the water and let gravity do the work, shooting water through a turbine to generate electricity.
Pumped storage has been around for decades, but its use has been limited under a fossil fuel scenario. Now that low-cost wind and solar energy have become significant elements in the US energy resource picture, the pumped storage field has new opportunities to expand. These facilities can absorb excess solar energy that would otherwise have to be curtailed during daytime peak generating periods, and they can put excess capacity from wind farms to use at night, too.
In addition to providing large scale energy storage, pumped hydropower facilities can be paired with next-generation turbine technology to provide frequency regulation and other valuable grid services.
The Devil Is In The Details
In this day and age of soaring infrastructure costs, a new pumped storage project also has a better chance of wriggling through the approval process than, say, a new Hoover-scale hydroelectric dam. Pumped storage facilities can be deployed in concert with existing dams, or they can take advantage of run-of-the-river opportunities.
To the extent that environmental and habitat conservation concerns are in play, pumped storage can also provide more room for the US hydropower industry to grow. One promising area of expansion is under way in Kentucky, where a former coal field is pulling second-life duty as the host of a giant “water battery.”
The latest sign of new life for the US hydropower industry is the proposed Carrizo Four Corners Pumped Storage Hydropower Center Project in New Mexico. It’s too early to tell if the project can pass muster with environmental concerns, but if a collaborative effort between the Navajo Nation and a study group spearheaded by New Mexico State University bears fruit, the Carrizo project could provide a fast-track model for others to follow.
Building The Case For Pumped Storage Hydropower
If all goes according to plan, the 1.5-gigawatt Carrizo project will be located entirely on Navajo Nation land in the Four Corners region at the border of Arizona, complete with 1.338 gigawatts of pumping capacity and 70 hours of storage duration.
If 70 hours sounds like a lot of storage duration, it is. Conventional utility-scale lithium-ion battery arrays only provide for about 4 hours of storage. The question is why New Mexico needs the extra 66 hours. The answer is provided by the NMSU team leader and principal investigator, assistant professor Fengyu Wang. Lithium-ion batteries can fulfill daily grid balancing chores and other routine tasks. However, they are not particularly adept at resolving the seasonal variations that arise in a grid saturated with wind and solar energy.
“The Carrizo Pumped Storage Hydropower project addresses the seasonal production-load mismatch critical for a reliable and cost-effective decarbonized grid,” Wang explained in a press statement earlier this week. “It will provide seasonal-duration storage to shift surplus variable renewable energy from spring to meet summer peak demand, and from early fall to offset winter underproduction.”
Wang also notes that the Carrizo project will be the cornerstone of efforts to ensure grid reliability in the event of extreme weather or extended lulls in wind or solar availability.
Along with frequency regulation, the Carrizo project is expected to provide voltage support and spinning reserve.
More Wind And Solar Energy For The USA
If you caught that thing about a decarbonized grid, that’s…interesting. In effect, pumped storage acts like a giant sponge for wind and solar, which are the only two domestic energy resources that failed to make the “American Energy Dominance” cut.
Nevertheless, with pumped storage hydropower enjoying federal support, the stage is set for a fresh burst of activity from the US wind and solar industries. The NMSU feasibility study is being funded by a $7.1 million award from the US Department of Energy, which the school will match on a cost sharing basis with $2 million from the Technology Enhancement Fund of the New Mexico Department of Higher Education and $1.1 million from the state’s Energy, Minerals and Natural Resources Department, among other sources.
One key sticking point, though, is the mismatch between construction timelines. Compared to the relatively quick pace of wind and solar development, hydropower projects of any sort move at a snail’s pace. However, the NMSU team is determined to give it a shot, and their effort could serve as a model for similar projects in the future.
“The project aims to fast-track Carrizo PSH licensing and permitting by conducting market analysis, geotechnical site investigations, tunneling and excavation planning, environmental permitting, and interconnection feasibility studies,” NMSU emphasizes.
More Renewable Energy For The USA
For the record, hydropower not the only renewable energy resource to enjoy protected status under the new “American Energy Dominance” plan. The nation’s domestic biomass and geothermal industries also share the pedestal.
The common denominator is the plan’s definition of “reliable” baseload power generation, meaning the 24/7 availability afforded by fossil-fueled power plants as well as nuclear power plants.
The idea of using wood waste and other biomass resources for 24/7 power generation has not gained much traction here in the US, partly on account of environmental considerations as well as supply chain complications. However, the offer of support from federal policy makers could help the industry shake itself out of the doldrums, with a possible assist from emerging links between the biochar and green hydrogen industries.
The US geothermal industry offers an even more promising area of 24/7 renewable energy generation. In past years the power generation side of the field has shown signs of stretching far beyond its current territory, scattered a among a few areas in the western US where the necessary combination of heat, hot water, and rock occurs by accident of nature.
Image (cropped): A proposed 1.5-gigawatt pumped storage hydropower project in New Mexico aims to leverage 70 hours of long duration energy storage capacity to help decarbonize the regional grid (courtesy of NMSU).
