Coal-Killing Long-Duration Energy Storage For Vermont (Vermont?!?)

Sign up for daily news updates from CleanTechnica on email. Or follow us on Google News!

Whelp, it looks like the US coal industry is going to end the 2010s the way it started. Back in 2009, US coal producers probably didn’t know they were staring down at the bottom of an abyss fueled by natural gas and renewable energy — or if they knew, they weren’t telling. Now that the 2020s are here, a major new threat to coal is taking shape in the form of long-duration energy storage. And it’s happening in Vermont, of all places.

energy storage long duration
Highview Power introduces new long duration energy storage technology to Vermont (image via Highview Power).

Wait, What Is Long Duration Energy Storage? (And Why?)

Aside from hydropower dams and “water batteries,”  no utility-scale storage technology on the market today can provide the long-duration standard of 10 or more hours. That goal has been set by the US Department of Energy, which would actually prefer a duration range of up to 100 hours but will settle for 10, for now.

Lithium-ion batteries are currently the go-to technology for energy storage, but they only provide for a few hours at a time. Scaling up an Li-ion array with staggered discharge times could be an option, but it’s not particularly cost-effective.

Meanwhile, the Energy Department is aggressively seeking long-duration, utility-scale batteries for two related reasons, neither of which spells good new for coal, or for that matter, natural gas.

First, more energy storage translates into more grid integration for renewables, which is another target of the Energy Department, despite anti-renewable mutterings from 1600 Pennsylvania Avenue.

Second, more grid integration for renewables means a greater need for modern grid services that provide for flexibility and resiliency, which can be fostered by utility scale energy storage.

More Energy Storage For Vermont

That brings us to Vermont. The UK company Highview Power is bringing its long-duration energy storage technology to Vermont in partnership with one of the top 20 solar developers in the US. That would be Vermont-based Encore Renewable Energy. For those of you keeping score at home, Encore won the #19 slot in Solar World’s “Top Solar Contractors” list.

The new project makes it clear why the Energy Department is eyeballing long duration energy storage for the sparkling green grid of the future. Highview’s big new battery will allow for bringing more renewables into the Vermont grid and that’s just for starters.

As described by Highview, the new battery will also provide market arbitrage, synchronous voltage support, frequency regulation and reserves, synchronous inertia, black start capabilities, and other services that monetize the facility while efficiently balancing electricity supply and demand.

So, How Does It Work?

CleanTechnica first took note of Highview’s new battery technology all the way back in 2011, and last summer the company finally announced it was ready for commercial development.

The basic idea is to use excess renewable energy to run a system that super-cools air down to a liquid state. It can sit there in a tank for days or even weeks until needed, then you simply warm it up. As the air heats up it expands. That provides the means to run a turbine, and there’s your renewable electricity-on-demand at any time of day or night.

Highview calls it the CRYOBattery. According to the company, the liquid air approach scales energy storage up to the gigawatts, and the levelized cost comes in at $140/MWh for a 10-hour, 200 MW/2 GWh system (levelized refers to a comparison between different types of energy storage).

The system planned for Vermont will weigh in at 50MW and provide for at least eight hours of storage, or about 400MWh.

Look Out, Natural Gas! Long-Duration Energy Storage Is Coming

So, here’s where it gets interesting. If the 2010s were the decade when coal died (spoiler alert: it was), the the 2020s will be the decade when natural gas loses its grip on the US power generation sector.

Here’s Highview on that topic:

“Highview Power’s cryogenic energy storage system is equivalent in performance to, and could potentially replace, a fossil fuel power station. Highview Power’s systems can enable renewable energy baseload power at large scale, while also supporting electricity and distribution systems and providing energy security.”

And then there’s this:

“Unlike competing long-duration technologies, such as pumped hydro-power or compressed air, Highview Power’s CRYOBattery™ can be sited just about anywhere. The CRYOBattery has a small footprint, even at multiple gigawatt-levels, and does not use hazardous materials.”

Oh, game on! Meanwhile over in Maine they’re looking into the potential for using hydrogen as a long duration storage medium that leverages excess renewable energy, so we’ll see how that goes.

Maine, Vermont … Anyone See A Pattern Here?

So, is it just a coincidence that the two adjacent states in the very farthest northeast corner of the US are both among the first to venture into long duration energy storage? Yes? No? If you have any thoughts about that, drop us a note in the comment thread.

Meanwhile, here’s a hint: both states are facing transmission bottlenecks.

In Vermont, the problem is the Sheffield-Highgate Export Interface. There were warnings of a problem as far back as 2012, as reliability issued come into conflict with consumer demands for more renewables.

A similar problem bedevils Maine, which is looking at the high cost of upgrading its transmission network and comparing that to the benefits of investing in energy storage.

It’s possible that Maine also has the Highview approach in its sights. The company has already hinted that it’s ready to move forward on projects all over the US, so CleanTechnica is reaching out to see if it can provide more specifics.

Follow me on Twitter.

Image (cropped): Liquid air battery courtesy of Highview Power.

Have a tip for CleanTechnica? Want to advertise? Want to suggest a guest for our CleanTech Talk podcast? Contact us here.

Latest CleanTechnica.TV Video

CleanTechnica uses affiliate links. See our policy here.

Tina Casey

Tina specializes in advanced energy technology, military sustainability, emerging materials, biofuels, ESG and related policy and political matters. Views expressed are her own. Follow her on LinkedIn, Threads, or Bluesky.

Tina Casey has 3292 posts and counting. See all posts by Tina Casey