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Clean energy journalism for a cooler tomorrow

Newsletter: The NASA technology keeping batteries cool on solar rooftops

The solar industry thrives on simplifying installations and cutting costs.
By Julian Spector

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The solar industry thrives on simplifying installations and cutting costs. Austin-based startup Yotta Energy does that by sticking miniature batteries right under solar panels, so customers don’t have to go through the hassle of installing a separate battery system.

But lithium-ion batteries come with a non-zero risk of catching fire if they get too hot, and solar panels on a roof in the height of summer certainly get toasty.

Yotta dealt with that by wrapping batteries in a heat exchange technology developed by NASA to keep spacecraft from overheating. Jeff St. John explains how that works — and how Yotta hopes to succeed where others have failed.

Don’t throw out your batteries!

As electric vehicles crawl out of their infancy, depleted battery packs belatedly accumulate. That fact has led many people to talk about the potential to use these second-life” batteries as cheaper alternatives to new grid batteries.

Now a few groups are starting to do something. In particular, California is seeding millions of dollars to put used car batteries to work. That’s logical for a state that has both a nation-leading EV market and an existential need for more batteries connected to the grid.

California reporter Elizabeth McCarthy has the scoop on projects up and down the Golden State attempting to overcome the persistent challenges of second-life batteries, including:

  • There’s no standardized way to acquire used EV batteries once they’re pulled out of cars.
  • Controlling batteries with different levels of degradation requires specialized software.
  • How long used batteries can survive in a grid storage project is an open question (an MIT study found that a decade of operation is achievable).

While we wait on the results of California’s grant-funded investigations, a company called B2U has been operating a second-life battery in California’s wholesale markets for over a year.

  • The facility in Lancaster, California is made of more than 200 used EV battery packs, adding up to 2.75 megawatts/​4 megawatt-hours. That’s small by conventional battery standards, huge by used battery standards.
  • The developer likes how the system has performed in the market and is adding more capacity. 

If you’re curious what it looks like to turn old car batteries into a power plant, this video offers a glimpse:

How much more money do we need to spend on grid resilience?

Clean energy consultancy ICF analyzed that question and determined U.S. utilities need to spend another $500 billion to fortify the grid between now and 2050.

The trick there is that regulated, investor-owned utilities make money for their shareholders by building things and earning a guaranteed profit from their customers. The structural incentive makes it necessary to ask whether any given grid upgrade really is necessary and in the public interest.

But we saw in 2020 that the current grid, even in the wealthiest states, can’t keep with the extreme weather that’s becoming disconcertingly frequent. Climate change promises more extreme events to come.

Two researchers from ICF penned an article for Canary Media with some suggestions for how utilities can make resilience planning more collaborative and holistic.

Even after disasters like Hurricane Sandy and California’s recent wildfires, microgrid construction proceeded slowly and haltingly. The status quo could certainly use some refreshment.

Julian Spector is a senior reporter at Canary Media. He reports on batteries, long-duration energy storage, low-carbon hydrogen and clean energy breakthroughs around the world.