Learn this Acronym: LDES – Long Duration Energy Storage

April 2, 2021

New studies and new tech for LDES – Long Duration Energy Storage.

SciTech Daily:

For their study, the researchers surveyed a range of long-duration technologies — some backed by the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) program — to define the plausible cost and performance attributes of future LDES systems based on five key parameters that encompass a range of mechanical, chemical, electrochemical, and thermal approaches. These include pumped hydropower storage, vanadium redox flow batteries, aqueous sulfur flow batteries, and firebrick resistance-heated thermal storage, among others.

“Think of a bathtub, where the parameter of energy storage capacity is analogous to the volume of the tub,” explains Jenkins. Continuing the analogy, another important parameter, charge power capacity, is the size of the faucet filling the tub, and discharge power capacity, the size of the drain. In the most generalized version of an LDES technology, each attribute of the system can be independently sized. In optimizing an energy system where LDES technology functions as “an economically attractive contributor to a lower-cost, carbon-free grid,” says Jenkins, the researchers found that the parameter that matters the most is energy storage capacity cost.

“For a comprehensive assessment of LDES technology design and its economic value to decarbonized grids, we evaluated nearly 18,000 distinctive cases,” Edington explains, “spanning variations in load and renewable resource availability, northern and southern latitude climates, different combinations of LDES technologies and LDES design parameters, and choice of competing firm low-carbon generation resources.”

Some of the key takeaways from the researchers’ rigorous analysis:

  • LDES technologies can offer more than a 10 percent reduction in the costs of deeply decarbonized electricity systems if the storage energy capacity cost (the cost to increase the size of the bathtub) remains under the threshold of $20/kilowatt-hour. This value could increase to 40 percent if energy capacity cost of future technologies is reduced to $1/kWh and to as much as 50 percent for the best combinations of parameters modeled in the space. For purposes of comparison, the current storage energy capacity cost of batteries is around $200/kWh.
  • Given today’s prevailing electricity demand patterns, the LDES energy capacity cost must fall below $10/kWh to replace nuclear power; for LDES to replace all firm power options entirely, the cost must fall below $1/kWh.
  • In scenarios with extensive electrification of transportation and other end-uses to meet economy-wide deep decarbonization goals, it will be more challenging in northern latitudes to displace firm generation under any likely future combination of costs and efficiency performance range for known LDES technologies. This is primarily due to greater peak electricity demand resulting from heating needs in colder climates.

Energy Storage News:

..the majority of new resources coming onto the grid are solar. On an average California day with plenty of sun, energy storage will be needed to dispatch for roughly 12 hours per day, increasing in winter to 14 or 15 hours per day.

Other resources that could store energy for up to 100 hours could help plug gaps in the case of extreme weather events. Childs said that there is often an assumption that these longer-duration resources which take the capabilities of storage far beyond the 2-4 hour benchmark that lithium-ion generally serves in California and even beyond the 10-16 hours that flow batteries provide, will find it difficult to find a business case.

This is based on assuming that those much longer-duration resources will only be called upon in infrequent circumstances, but this is not true, according to CESA and Strategen’s study, because those resources will still likely be called upon “to dispatch for many hours a year” and “can be very active in the market place,” Childs said. 

Over the next 10 years, “a good amount” of short-duration energy storage will come onto the grid, but in the years between 2030 and 2045, if efforts to decarbonise are to be successful, the electric system will almost exclusively need longer-duration resources to enable daily cycling of solar and meet evening ramp-up requirements, but also more broadly to run in the evening and night-time to provide the grid with reliable service.


What engineers would like are Big Storage technologies that can supply power five to 10 times more cheaply than today’s lithium-ion batteries, and can do so for much longer. How much longer is an open question. The U.S. Department of Energy research-and-development shop known as ARPA-E put $28 million into 10 early technologies back in 2018 that may lead to systems capable of feeding a grid for anywhere from 10 hours to 100 hours. That’s “obviously a very large range,” as a Sandia National Laboratories policy analyst wrote in January. It’s the difference between providing power on a cloudy day and covering for extreme weather that limits power generation for weeks. 

Big Storage technologies are as diverse as the engineering shops that are producing them. Raytheon Technologies Corporation is working on an alternative-chemistry “flow battery” made from inexpensive sulfur and manganese. Form Energy Inc., based in Massachusetts and backed by Bill Gates’s Breakthrough Energy Ventures, is building yet another kind of battery that they say will be able to store 150 hours of power. Led by Mateo Jaramillo, who left Tesla Inc. as its stationary storage chief in 2017, the startup last year announced a pilot project in Minnesota.

With so many possible approaches, from hydro systems to unconventional batteries and heat, it’s a dizzying moment for governments, researchers, businesses and investors to think about what to work on first.

PV Magazine:

Form Energy remains a secretive, long-duration energy storage startup funded by Bill Gates’ Breakthrough Energy Ventures and other investors.

The company has revealed that its fundamental energy storage technology is an “aqueous air battery system” that “leverages some of the safest, cheapest, most abundant materials on the planet” in order to commercially deploy a 1 MW/150 MWh long-duration storage solution.

Typical lithium ion battery storage systems provide four hours of storage compared to Form’s remarkable of 150 hours of storage. It’s not exactly the “seasonal” storage that Mateo Jaramillo, CEO of Form Energy, had spoken of in the past — but it’s a few orders of magnitude better than what can be done today.

Unconfirmed sources claim that Form’s sulfur battery chemistry can only support very low discharge rates “and they’re trying to pass it off as an advantage. Pretty much any battery can hold energy for 150 hours or more.”

The CEO, an energy storage veteran, has referred to the company’s product as a “bi-directional power plant” and claims that this level of  duration allows for “a fundamentally new reliability function to be provided to the grid from storage, one historically only available from thermal generation resources.”

The first project

Form Energy’s first commercial project is a 1 MW, grid-connected storage system capable of delivering its rated power continuously for 150 hours with Minnesota-based utility Great River Energy.

Great River Energy is a not-for-profit wholesale electric power cooperative that provides electricity to 28 member-owner distribution cooperatives, serving 700,000 families, farms and businesses. It’s Minnesota’s second-largest electric utility.

“Commercially viable long-duration storage could increase reliability by ensuring that the power generated by renewable energy is available at all hours to serve our membership. Such storage could be particularly important during extreme weather conditions that last several days. Long-duration storage also provides an excellent hedge against volatile energy prices,” said Great River Energy VP Jon Brekke, in a release.

“A true low-cost, long-duration energy storage solution that can sustain output for days, would fill gaps in wind and solar energy production that would otherwise require firing up a fossil-fueled power plant,” said Jesse Jenkins, an assistant professor at Princeton University.

One Response to “Learn this Acronym: LDES – Long Duration Energy Storage”

  1. Brent Jensen-Schmidt Says:

    Most informative post and the holy grail is right on.

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