This opinion piece from TWW’s Greg Brophy originally ran in Colorado Politics on July 12, 2023 and can be accessed here.
Over the next decade, rural communities in Western states have a huge opportunity to increase the amount of energy they provide to major urban centers. By making the most of this opportunity, we can strengthen our communities with more investment, jobs and funding for critical services.
That’s true across all energy technologies, including oil and gas, hydrogen, carbon capture and advanced nuclear. But it’s especially true for renewable sources of energy like wind farms and solar arrays, which have found a natural home on the eastern plains of Colorado, where I’m from, and in many other rural areas across the western United States.
We have some barriers to overcome, however. The most talked about is the need for more long-distance power transmission lines to move all that electricity from the farming and ranching communities where it’s produced to the cities and suburbs where it’s consumed.
But expanding the amount of energy storage available to power grid operators is another major challenge that deserves more attention.
With more storage, electricity generated when the wind is blowing and the sun is shining doesn’t have to be used right away — it can be used at any hour of the day or night, regardless of weather conditions.
That’s good for the reliability of the power grid, but it’s also good for rural communities, because energy storage effectively grows the market for the electricity they produce.
For this reason, lawmakers and power grid regulators need to look at all the viable energy storage technologies — not just bigger versions of the lithium-ion batteries that currently power our phones, laptops and even electric cars.
One of the most promising of those technologies is called pumped hydro storage. It’s not a new technology, and despite all the attention given to lithium-ion batteries, pumped hydro storage provides more than 90% of the energy storage available on the U.S. power grid today.
According to the Pacific Northwest National Laboratory (PNNL), pumped hydro storage is “a mature technology that includes pumping water from a lower reservoir to a higher one where it is stored until needed.”
When electricity from renewable sources is used to run those pumps, that renewable energy is stored. When the water is released, “it flows back down through a turbine and generates electricity,” according to PNNL.
Effectively, pumped hydro storage functions as a water-based battery, using technology that’s been around a lot longer than lithium-ion battery technology.
For this reason, pumped hydro is one of the lowest-cost technologies for energy storage. According to PNNL, once built, a pumped hydro storage facility can function for 60 years or more without the same kind of maintenance and repair costs that apply to electrochemical battery technologies like lithium-ion.
Just like the batteries in your cellphone, laptop or electric car must be reconditioned or replaced over time, so do the much larger batteries used to store electricity for the power grid — and that adds cost.
That’s not the case for pumped hydro storage. “It doesn’t degrade no matter how much you cycle it up and down,” Matthew Shapiro, the CEO of rPlus Hydro, said in an interview with The Western Way.
With 15 pumped storage projects in development across the U.S., officials at rPlus Hydro say their technology isn’t meant to directly compete with electrochemical batteries. In fact, rPlus Hydro’s parent company — rPlus Energies — builds solar arrays that are paired with battery-based storage systems.
It turns out lithium-ion batteries are good at storing and discharging electricity in short bursts, while pumped storage hydro can provide many more hours of backup power to the grid.
“It’s not an ‘us’ versus ‘them’ dynamic,” Shapiro said. “Batteries are good for short durations of between two and four hours. Pumped storage typically works well over an eight-hour duration.”
Another cost-saving feature: pumped hydro storage doesn’t rely on the same supply chain as consumer electronics and electric cars. Though there are moves to reform project permitting and build more mines in America, the global supply of critical minerals needed for batteries and other low-carbon energy technologies is currently dominated by foreign nations, especially China.
Until that changes, “there’s a lot of concern about battery supply chains, especially with the growing appetite for electric vehicles in the automotive sector,” Shapiro said.
The lesson for lawmakers and regulators is clear: policies to expand energy storage can’t be solely focused on lithium-ion or other kinds of electrochemical battery technologies.
Reforms to speed up the permitting process and incentivize the construction of energy storage facilities must be applied broadly to include established technologies, including pumped hydro storage.
Chasing new technologies is all well and good. But for the sake of our energy security and the rural communities that make that security possible, we must not lose sight of the technologies we already have.
Greg Brophy, from Wray, is a farmer and former state senator. He is the Colorado director of The Western Way.