Paul Gerke and Mike Casey cover how old batteries, solar panels, wind blades and grid gear are becoming a new source of critical minerals, and how Britain plans to balance a fast-growing grid. They dig into Zeke Hausfather’s analysis showing wind and solar avoided 3.7 billion tons of carbon pollution in 2025, and why tandem solar panels could help the US catch China. Grist’s Benton Graham explains the battery-powered commuter trains coming to Boston, Chicago and the Bay Area. Cleantecher of the Week is chef Christopher Galarza, whose study found unsafe NO2 levels in gas-fired kitchens.

Episode 150: Featuring Benton Graham of Grist

Overview

The energy transition is starting to feed itself — Reuters
How to keep the lights on in an electrified world — The Financial Times
What if the world hadn't built wind and solar? — The Climate Brink
US Solar Panel Makers Try to Catch China With a Big Leap in Technology — The New York Times
The future of commuter rail could be taking shape in Boston — Grist

Paul Gerke: Hey everybody and welcome to another edition of This Week in Cleantech. We’re giggling at the 00:00:01 mark. So it’s a good start to the show. We try to do the program in 15 minutes or so. It’s about the biggest stories in climate and clean energy each week. No, we do. We put a line in the sand at the beginning and then we fail to meet it by the time we get to the end. We limp across the finish line with a few extra minutes saddled to our backs. Anyway, we’re recording the show for Friday, October 9th, 2026. We got a first time guest on the horn. Benton Graham from Grist is waiting in our lobby. He’ll be joining us shortly. I am Factor This content director Paul Gerke, joined once again by cleantech commentator Mike Casey of Tigercomm and my dog Theo, who is waiting patiently next to me at my desk for me to finish this podcast so we can go on a walk. It’s a lovely day out here, Mike. Hope it’s nice where you are.

Mike Casey: It is, man. It really is. Hey, a listener shout out to Zach. I think that’s how you pronounce his name.

Paul Gerke: Don’t shout that out loud in front of anybody.

Mike Casey: Zach is with Tesla Energy. He’s got a new podcast summary service, which he is already summarizing our show. He describes it as follows. “The energy conversation is scattered across dozens of podcasts. Each week, energypod.io distills them into a short briefing. What happened and why it matters for busy energy professionals.” But you should never be too busy to listen to us. Keep it under 20 minutes. That’s the point of this show. So hat tip to Zach.

Paul Gerke: Wait. So, is he telling people to listen to us or don’t listen to us? Cuz he’s just going to tell us what we talked about in two sentences. Do we like Zach or is he an enemy?

Mike Casey: I think he suckered me. I think he got me to promote his...

Paul Gerke: You read an ad that we didn’t get paid for.

Mike Casey: And we’re going to go from 25 listeners down to 22 because of this. Hey, if you’re listening to this and you want an ad on the show, you got to pay us for it. Don’t trick us like Zach did.

Paul Gerke: And if you want to get your opinions on the show, we always have an open line for that, too. The viewers and listeners help make the program. You could just email us, whether it’s a story suggestion or two cents you want to share, twic@tigercomm.us. All right, Mike, let’s do this story for our new rival, Zach. First one of the week. What’s on top?

The Energy Transition Is Starting to Feed Itself

Mike Casey: Gavin Maguire, Reuters. “The energy transition is starting to feed itself.” This is a cool story.

Paul Gerke: Ooh, I like it. Cool headline. EVs, solar, batteries and the grid. We all need a lot of stuff from the ground to make those things real. Copper, rare earths, silver, other minerals. Fossil fuel energy doesn’t necessarily need all that stuff. But new mines and refineries take years to come online to support the clean energy ambitions we talk about on this show. And one of the most promising new sources of supply is the energy transition’s own hardware. We’re talking about old batteries, retired solar panels, decommissioned wind turbines, aging grid equipment. For example, Redwood Materials says it recovers more than 95% of the lithium, nickel, cobalt, and copper from spent batteries and factory scrap, producing more than 60,000 metric tons of critical materials each year. The first wave of big EV batteries is now starting to age out, and that pile is only going to grow. The IEA says recycling could cover 20 to 30% of global lithium, nickel, and cobalt demand by 2050. And we’re catching up on solar, too. Despite some recent research that you may have seen that says a lot of solar recycling is a scam, Dutch researchers recovered silicon at up to a 99.99% purity. So, it can be done. A team in Australia got nearly 100% silver recovery. So, we’ve seen some progress there. Mike, your thoughts on this?

Mike Casey: My thought is that cleantech hating is among the biggest scams on earth because these guys are always huffing glue and then saying silly things. But there we go. Rystad Energy thinks the value of recyclable materials in solar panels could jump from about 2 billion today to roughly 80 billion by 2050. By 2035, panels installed back in 2020 could supply as much as 21% of the silver needed to build new ones. So, wind blades, they’ve been a problem because they’re made of composites that are hard to break down. Veolia now shreds them into pellets that can replace coal, silica, and limestone in cement kilns. One 7-ton blade cuts about 5 tons of coal. I love that. And then there’s what you could call grid mining. Utilities are swapping out old transformers, substations, and transmission gear packed with high-quality copper, aluminum, and steel. New Core runs facilities that recover those metals and feed them into new transmission components. Paul, story number two.

How to Keep the Lights On in an Electrified World

Paul Gerke: I know some folks that have done some grid mining back when I used to live in Michigan, ripping copper out of buildings and stuff. The public can do grid mining, too. We just don’t encourage it. Dangerous. Dangerous stuff. Anyway, story number two. Second story this week. Rachel Millard, Ian Bott, Aditi Bhandari, Clara Murray, and Richard Topping, all writing for the Financial Times. A piece titled “How to keep the lights on in an electrified world.” Tell me about it, Casey.

Mike Casey: Yeah, balancing the grid used to mean dispatching new fossil fuel plants. Now operators are managing hundreds of wind and solar farms, plus a flood of rooftop solar. That’s tough to forecast, with power flowing both ways between customers and the grid. At the same time, demand is climbing as people switch to EVs and heat pumps. Britain’s grid operator thinks the country’s total generating capacity might need to grow by 206% to 245% from 2024 to 2050 just to keep up. And just over a third of that increase has to be storage or dispatchable power, meaning something you can turn up and down on command. So Britain, they built a much bigger grid and a much more flexible one at that. It’s leaning heavily on EVs. Octopus Energy, the country’s largest household supplier, says smart charging, where cars charge automatically when power is cheap and plentiful, is going mainstream fast. Paul, your thoughts?

Paul Gerke: Batteries are a big deal and they’re only going to get bigger. They’re right now the fastest growing electricity technology in the world because of their versatility. Britain’s got about 8 gigawatts of batteries, most of those 2-hour systems. Aurora Energy Research expects that to more than double in 5 years. And we’ve seen a lot of that here in the States. For longer stretches of time outside of what batteries can provide, regulators are backing SSE’s Coire Glas project in Scotland. It’s a new hydro project, the first in a generation. It would pump water uphill when power’s cheap and then release it when prices rise, supplying 1.4 gigawatts for 32 hours straight. Regulators are looking into compressed air storage in salt caverns. Things like storing air as a chilled liquid, also an option. There are interconnectors, big undersea cables linking Britain to Europe. Net imports covered just over 9% of UK demand last year, but neighbors often have the same weather. This summer, the grid operator had to abruptly cut exports to the Netherlands during a windless hot night. Even so, the grid operator expects Britain to be a net exporter of electricity by the year 2030. Mike, get us to story three.

What If the World Hadn’t Built Wind and Solar?

Mike Casey: Zeke Hausfather from The Climate Brink. He wrote, “What if the world hadn’t built wind and solar?” I could summarize the story by saying we’d be effed, but that would not be good for our show.

Paul Gerke: I don’t know what we’d be doing the show about. Yeah, it’s something else probably. A common argument online is renewables aren’t replacing fossil fuels at all. They’re just sort of an “and” proposition. If you look at only the numbers on paper, it’s hard to argue with that. Coal power hit a record in 2024. Gas hit a record in 2025. Global fossil fuel generation is about 50% higher than it was just 20-some years ago. Zeke argues this is the wrong comparison though. Global electricity demand grew 75% over those 20 years because of industry, EVs, air conditioning, data centers, on down the line. Did you catch it there? I said data centers. That demand was coming whether we built a single wind turbine or not. I like to just mix it up. Keep you guessing, Casey. Since 2015, wind and solar met 57% of new demand. That’s way less than fossil fuels did at only 29%. Last year they covered 99% of it. Mike, what would you do if we didn’t have wind and solar to talk about?

Mike Casey: So Zeke, in his analysis, went back to 2005 and he froze wind and solar levels at that year’s output in every country and filled the gap with that country’s own fossil fuel mix, traditional fossil fuel mix. Coal in places like China and India, mostly gas in places like Texas or the UK. Without that growth, global power sector pollution would have been 28% higher last year. That’s 3.7 billion tons of carbon pollution avoided in 2025 alone. About 3/4 of total US carbon pollution. Over the full 20 years, it’s roughly 23 billion tons. So in places where demand grew slowly, clean energy actually pushed fossil generation down. EU power pollution fell 55% since 2005. Without wind and solar, that would have been about 16%. In the US, it would have been about 17% instead of 37. So 60% of this avoided pollution came in just the last 5 years. Paul, story four.

A New Crop of Solar Panels Is the US’s Best Hope of Catching China

Paul Gerke: One of your favorite authors, Ivan Penn over at the New York Times, titled “A new crop of solar panels is the US’s best hope of catching China.” Tell me about it.

Mike Casey: You know, Ivan is so much better a reporter than David Wallace-Wells because Ivan chose to come on the show, and I think that’s qualification.

Paul Gerke: That’s all it takes.

Mike Casey: Yeah, for sure. Right. Okay. So, this is actually really cool. US solar manufacturers say they’re close to a breakthrough with tandem solar panels, which stack extra layers of material on top of each other, kind of like a layer cake, so the panel can turn more sunlight into electricity. The goal is about 25% more energy than most panels on the market today. Tandem PV, First Solar, and Qcells all say they’re getting ready to sell them commercially soon. Qcells, which we covered back in June when it started making solar cells at its Cartersville, Georgia plant, is now the first company to get a tandem panel independently certified. And this matters because China, as listeners to this show well know, controls 80% of the solar panel market in the world. Getting tandems right first could give the US and its allies a shot at winning back a big piece of this industry, which I’m sure the current clown show running federal policy will rush to give away to China, since that’s what they love to do.

Paul Gerke: I’ve got to be the naysayer here and say hold on, Mike Casey, because there are some hurdles to clear here. You’ve got to convince not only developers but the people signing the checks at the banks that these things are going to last 20 to 30 years. So Qcells right now is shooting golf ball-sized chunks of ice at its panels to prove that they’re durable. These things are also expensive. A lot of estimates put tandems at three to three and a half times the cost of a regular panel. The upside is hard to deny though, that extra, you know, 24% capacity. Solar farms in the US run at a 24% capacity factor, meaning how much power they actually produce compared to their max. Tandems could get above 31%, according to some research. So the same power, fewer materials, same site. Scott Wharton at Tandem PV says his panels are degrading less than 1% per year and tandems will dominate the industry by the mid-2030s. Scott, we’ll have to get you on the show to talk about that if that’s the case, because of course the show will last forever. That’s the way we’ve set it up.

Mike Casey: It will last longer than time.

Paul Gerke: It feels like this episode’s headed that direction. Let’s bring our guest in. Mike, story five.

The Future of Commuter Rail Could Be Taking Shape in Boston

Mike Casey: We’re cruising to a very prompt ending, Paul Gerke.

Paul Gerke: Benton Graham from Grist. Yeah, we welcome you, Benton. You’ve got a piece, “The future of commuter rail could be taking shape in Boston.” Tell us about the story. What’s the big takeaway?

Benton Graham: Yeah, thanks for having me. Yeah, so rail electrification, it’s nothing new, right? It’s something that we’ve been doing for 140 years, electrifying streetcars back in the late 19th century. But what’s new here is, you know, for a long time that’s meant overhead wiring, installing third rail, very costly infrastructure projects. Now, as you guys were talking about the importance of batteries, there’s kind of an emerging technology around battery-powered trains, which is significant because, you know, instead of retrofitting your rail radically, you can hop a battery-powered train onto tracks that are typically built for diesel. So this is kind of something that some public transit agencies, commuter rail lines are testing out in the US. Caltrain in the Bay Area, Metra in Chicago in 2028, and then the T in Boston in 2030.

Paul Gerke: It sounds like there’s a path here for broader adoption. Benton, the rail that you wrote about in your piece, that was not a quick project. I think there was advocacy work for that project for something like 30 years to make that one happen. In your reporting, what do you see as the wider scale adoption play here in the United States for technology like this?

Benton Graham: Yeah, I think we’re going to learn a lot about that over the next five or so years. I should say it’s something that’s not only happening in the US. There are battery-powered trains in Germany, and I believe the UK is introducing some as well. So this is, you know, something that Europe might give us some insight into. But as far as adoption in the US, I think it’s going to kind of depend on how things go in Boston, Chicago, the Bay Area. And, you know, a couple things to consider. You know, is the rollout of these trains super bumpy? Like with any, you know, with EVs, like the charge range is a question, right? Boston, Chicago, these are harsh winter climates. Is that a problem? But I think that’s, you know, one thing to consider. And then there’s the cost piece, too. I mean, in reporting on the story, the T said a big reason that they pursued this technology is because battery-powered trains were a huge cost saver compared to installing overhead wiring. I mean, just for one example, Caltrain in the Bay Area installed overhead wiring from San Jose to San Francisco. That was about $2.4 billion. So that is super costly. But I think it’s also important to note that Boston is spending $765 million for a 15-year lease. They’re not even purchasing these battery-powered trains. So I think it’s going to kind of depend on, can that cost come down? Obviously, we’ve seen the cost of batteries falling for a long time now. So hopefully that’ll be the case. But if these trains, you know, can save a lot of money on kind of those big infrastructure project investments that would be required to electrify. Yeah, I mean, it is something that could wind up being appealing to regional railroads and, who knows, maybe someday, you know, beyond that, Amtrak and kind of intercity rail as well.

Mike Casey: And how do these batteries the trains use compare to what would go in a car? I know size is obviously different, but are they using different technology, and are there things that they take into account?

Benton Graham: I think, you know, that’s a good question, and I don’t know, like, the technological intricacies of how different it is, but I do think there are a lot of similarities. And, you know, like the example I was giving someone the other day is like, you know, you could think of it like a Tesla, or even, like, I think maybe a better example would be electric-powered buses. We’ve seen the rollout of those struggle in some cold weather climates. I think, you know, Duluth, Minnesota, way up north, they tried to roll these buses out 5, 6 years ago. Didn’t work well. But now we’re starting to see cold weather climates like Madison, Wisconsin, places like that, have some success. So I think the general battery technology is pretty comparable, in terms of what some of the challenges are, is pretty comparable. You compare, like, trains and buses and EVs.

Cleantecher of the Week

Mike Casey: Well, I think we’re about out of time. We need to go to our Cleantecher of the Week.

Paul Gerke: Let’s do it. This week’s Cleantecher of the Week is, drum roll please, Christopher Galarza, longtime chef and co-founder of Ecochef. They certify sustainable commercial kitchens. Christopher co-authored a new peer-reviewed study, recruited most of the kitchens in it. Theo, I’m reading Cleantecher of the Week, buddy. Theo says, “Congratulations to Christopher.” He co-authored a new peer-reviewed study, as I mentioned, recruiting most of the kitchens in it, and found that 70% of gas-fired restaurant kitchens had nitrogen dioxide levels above EPA and WHO safety limits. WHO, that’s the WHO, not the band, not to be confused. That’s even with commercial ventilation. Chris says working in all-electric kitchens was the first time in his career he could do what he loved without feeling like he was dying. Congratulations, Christopher, Cleantecher of the Week.

Mike Casey: Outstanding. And Paul, I want to acknowledge this is a personal growth moment for you, that you said data centers, because I’ll bet you if I asked Benton if it’s data or data centers, he’s a data guy.

Paul Gerke: Benton looks like a data guy. What do you got? Data or data? Bring it.

Benton Graham: Data. I got to say data.

Paul Gerke: I’m starting to lose big time. You’re keeping track, aren’t you? It’s like 7 to 2 or something now.

Mike Casey: You and Clara Hudson on an island by yourselves.

Paul Gerke: Okay.

Benton Graham: Is there a regional split?

Paul Gerke: Oh, I think it’s just now I’m being stubborn about it. I like data. Data sounds more formal to me. Data sounds like you’re getting on Facebook. Data sounds like you’re researching something important.

Conclusion

Mike Casey: Well, you know what it sounds like? We need to thank Clare Quirin and Alex Petersen for gathering these stories.

Paul Gerke: And if you guys have any strong opinions on data versus data centers, please, I need some support. I’m getting killed over here. Thanks for joining us for another round of This Week in Cleantech. Special shout out to Benton Graham for sticking around and laughing at our corny jokes. If you enjoyed them, please subscribe, leave a little feedback, and share a story suggestion if you like. You can read every article we talk about each week. There are links in the episode description, as well as where this thing lives on factorthis.com. Until next time, be good people.

Mike Casey: Under 20 minutes, baby. Woo! Right there.