Energy storage could become a big enough factor in the United States power grid to help drive fossil fuels out of the system, reduce greenhouse gas emissions, and balance electricity loads at every hour of every day year-round by 2050, according to analysis released earlier this month by the National Renewable Energy Laboratory (NREL).
Measuring the value of energy storage is “inherently complex”, NREL says, in a summary of the first report from its multi-year Storage Futures Study (SFS). But “with declining costs, improved technologies, and increasing deployment, energy storage is poised to become a growing part of the evolving U.S. power system.”
The report sees storage on the U.S. grid evolving through four phases:
• Short-duration storage, already under way since the early 2000s, to supply operating reserve to wholesale electricity markets;
• Cost-competitive battery peaking plants with two to six hours of duration;
• Low-cost diurnal storage to even out longer periods of peak demand;
• Multi-day and seasonal storage.
All told, the four stages could deliver hundreds of gigawatts of storage across the U.S. by mid-century, representing “a significant shift in our electric grid,” NREL writes.
“NREL researchers modelled a series of scenarios for possible energy storage deployment through to 2050, including a reference case, a low-cost battery scenario, low-cost solar PV, high natural gas cost combined with low-cost batteries, and a zero-carbon scenario,” Energy Storage News writes. In the most modest scenario, U.S. energy storage expands almost tenfold by over the next 28 years.
“Even in the reference case, the amount of energy storage on the grid rises to 213 GW by 2050 from about 23 GW installed today—with nearly all of today’s installations pumped hydro, despite the rapid rise of lithium-ion starting to account for significant numbers,” the news story states. “In the low-cost battery scenario, that figure rises to 384GW/1,792GWh, and in the zero-carbon scenario as much as 932GW/6,097GWh.”
In particular, Energy Storage News says, the technologies emerge as a “valuable application” to even out peaks in user demand for electricity. “The major need for energy storage, as a peaking capacity asset, will be consistent throughout the year, but it will be most valuable for about 10 hours of every year when the grid endures its highest peaks in demand. As more fossil fuel-fired peaking generation retires, that value grows.”
Storage will also help operators make less use of those fossil plants while they’re still on the system, ESN adds. “Increased energy storage deployment can result in fossil fuel generators having to be used less frequently, and avoiding start-ups of polluting thermal power plants can have beneficial impacts on public health, especially for those living nearest to those power plants.”
More specifically, the number of gas plant start-ups required per day falls from 400 to as low as five per day between the reference case and the high-end scenarios, Utility Dive reports. The analysis also finds that storage is flexible enough to allow different grid regions to select the lowest-cost mix of resources, while reducing congestion on some transmission lines.
“Essentially, the storage technology plays a key role during peak demand when the power system needs energy and capacity the most,” said NREL researcher and lead author Jennie Jorgenson. “We find this consistently across all scenarios and years through 2050,” leading to the conclusion that “the potential future energy system with large quantities of energy storage could successfully balance load 24/7.”