The challenges with long-duration energy storage

One of the biggest challenges that needs to be solved within the clean technology space is the issue of storage, in particular,long-duration energy storage (LDES). At the start of this past winter, the Northeast Clean Energy Council (NECEC) hosted a Cleantech Executive Roundtable discussion on modernizing the grid with long-duration storage. This event brought together thought leaders from the public and private sector to discuss how best LDES can be deployed in the northeast and achieve the most impact.

This event featured representatives from non-profits and governmental agencies such as NECEC; the New York State Energy Research and Development Authority (NYSERDA); the Massachusetts Clean Energy Center (MassCEC); startups such as Form Energy and Malta; large utilities and electricity providers such as Direct Energy, Engie, National Grid, Eversource and Avangrid; venture capital firms such as Breakthrough Energy Ventures (BEV); and additional energy and tech businesses such as Analog Devices, Shell, and Toyota. Keynote speakers included Ted Wiley, CEO of Form Energy, and Albert Morales, CFO of Malta – representing the two most prominent startups based here in the Northeast that are expected to fundamentally disrupt the energy storage space.

Form Energy is developing an iron-based battery that can deliver 1MW of power for over 100 hours. Iron is the 2nd most mined mineral on the planet behind coal, a state of affairs that really needs to change. The expected cost of this battery at scale is $20/kWh and they hope to deploy it in 2023 or 2024. This battery, if proven successful, would be a major game-changer in the LDES space as it could allow renewables to provide almost a week of storage capacity inside of our energy grid. No more rare earth materials required, just readily available iron for low-cost, reliable power.

Malta, a pumped heat storage startup, has put together a long-duration energy storage solution that is grid-scale (10 to 100MW) and low cost (<$100/kWh). Malta’s storage system has a duration of up to 200 hours of energy with a round trip efficiency between 55% and 65%. They are hoping to commission their storage project in Q1 2024. The system will be used for frequency response, reactive power, voltage management, inertia and capacity.

In preparation for this event, a detailed pre-read report was put together discussing all the different long-duration battery technologies, their pros and cons, challenges in the industry, and possible policies to enable the proliferation of such technology. The work involved interviewing industry thought leaders across start-ups/venture capital firms/non-profit organizations, reviewing published reports, and meeting with members of academia.

One of the conclusions was hydrogen appears to be best for extremely long energy storage challenges requiring multiple weeks or months of storage, while flow, zinc and pumped hydro, appear to be best for < 1-day storage. Pumped heat and metal-air batteries profile as best medium-duration LDES solutions to get about a week of storage. The largest roadblocks for LDES appear to be cost, technology readiness, societal blowback, appropriate market valuations for >4 hours of storage, and not yet having enough renewable grid penetration.

Other technologies, such as methane gas can also meet the needs for LDES for an effective price, but fail the test from a greenhouse gas emissions perspective.  Policies that will be most effective in helping LDES proliferate will be those that have a positive incentive such as tax credits, subsidies, and mandates. Overall, the future looks promising for LDES solutions as there are many options available and many bright minds working to bring these technologies to the forefront of our society.

Written by Kelly Ogiesoba, NECEC Fall Development Intern and MBA student at Harvard Business School

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