Clean power for off-grid locations

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Repurposing instead of retiring

“Shutting down coal plants only gets you so far,” says Julian Spector of Canary Media in a recent newsletter. “It's progress,” he continues, “for cleaning up power sector emissions, certainly. But closures, absent other action, leave behind vast industrial sites, job losses, and financially bruised communities.” Closures also leave plant owners with stranded assets which may have remaining operational life, making companies reluctant to shut down the plants in the first place.

What if there were a way to keep the plants operating while eliminating the pollution from coal-fired operation? Spector points to a coal plant in Maryland (USA) that has found at least a partial solution.

Talen Energy, a privately held company that owns power plants across the mid-Atlantic, is building a 20 MW battery installation at the site of a coal generator it recently shut down near Baltimore. According to Talen, coal sites have distinct advantages for new battery construction. They often control a lot of land, which provides room to install renewable generation like solar and wind. Plus, they can use the coal plant's existing grid hookup, which simplifies permitting and project costs.

Batteries also have the advantage that they can respond to demand surges much more quickly than could the coal plants they’re replacing. The catch is that conventional electrochemical batteries are only good for about 4 hours of operation before they have to recharge.

Says Spector, “I've reported on batteries for the last five years, but this is the first time I've talked to anyone building them at a coal plant.” It’s unlikely, however, to be the last. He quotes Talen’s Cole Muller as saying that his company wanted more of a comprehensive strategy for this transition than just walking away from the plants. “If you just retire it, you have a significant loss to both jobs and the tax base, and the communities at large.”

Keeping plants operating, cleanly

Earlier we described Talen’s solution as “partial.” That’s because it leaves the existing coal-fired steam plant sitting there unused. 247Solar’s HeatStorE™ Combined-Cycle Thermal Battery (CCTB—introduced to regular readers last month) offers an opportunity to keep steam plants like Talen’s operating, without burning coal.

HeatStorE converts excess grid power to heat, and stores that heat at extremely high temperatures for up to 20 hours. When needed, it converts the heat back to power. In addition, 640℃ exhaust heat from multiple batteries can also be used to deliver steam to power existing steam turbines.

HeatStorE is a superior alternative to expensive long-duration electrochemical batteries. Our CCTB can be used as either a large, long-duration battery, an emergency long-duration back-up reserve, or a 24/7 dispatchable power plant by burning fuels, including hydrogen.

Contact us if you’d like to learn more.





It’s been a few issues since we’ve written about microgrids, but this month we came across a couple of articles in Microgrid Knowledge that caught our attention.

How to Bring Microgrids to Areas Without Electricity

Summarizing comments from a session on “New Strategies to Hasten Microgrid Adoption in Remote Regions” at their recent Microgrid 2021 conference, the authors address the challenges of bringing microgrids to the more than 800 million people who still lack electricity around the world. These include costs, technology and financing. But at the end of the day, according to panelists, people are at the center of successful projects. A project’s long-term success centers on the interaction between a community and the technology.

But What About Microgrids? CNN Host Probes Officials

This piece recaps comments from US Secretary of Energy Jennifer Granholm and other political leaders during a virtual forum on resilience with CNN host Fareed Zakaria. Granholm is quoted as saying that microgrids are an important component of creating redundancy, and they are “a technology that is available.” She adds that microgrids make particular sense for places such as Texas because it is walled off electrically from the rest of the country, and California where wildfire related power outages leave swaths of the state in the dark. Clean microgrids, of course.