Senate Overturns California Waiver, Defying Parliamentarian

Current conditions: Showers and thunderstorms in the South and cool weather in the Northeast will make Memorial Day weekend “more reminiscent of late March than late May” • At least four people are dead and 50,000 stranded in New South Wales, Australia, due to torrential rainfall that is expected to ease Friday evening • Evacuation orders are in place around Oracle, Arizona, to the north of Tucson, due to the growing Cody Fire.

THE TOP FIVE

1. Senate strikes down California waiver

It’s official: After weeks of speculation and run-up, the Senate voted 51 to 44 on Thursday to overturn California’s waiver from the Clean Air Act to set stricter-than-federal emissions limits on cars and trucks. The vote was along party lines, with the exception of Michigan Democrat Elissa Slotkin, who joined Republicans in passing the disapproval resolution under the Congressional Review Act. California required companies to stop selling new gas vehicles by 2035, which Republicans had criticized as an “electric vehicle mandate” due to the size of the state and its influence over the automotive market.

The Senate’s parliamentarian and the Government Accountability Office had determined that the Senate could not use the CRA to prevent California from setting stricter emissions standards, as it has done since 1967, because the waiver is not a federal rule and therefore not subject to a simple 50-vote threshold repeal vote. To get around the technicality, Republicans voted Wednesday night on what Rhode Island Democratic Senator Sheldon Whitehouse called the “double nuclear option” — essentially declaring they were “within their rights to skirt a filibuster and muscle through measures to deny” California its unique emissions-setting authority, The New York Times writes. But that also means the door is now open “to challenges against all sorts of other federal program waivers — without having to worry about the Senate filibuster,” Capitol Hill correspondent Jamie Dupree wrote in his newsletter Thursday, adding, “it certainly is a substantial change in the precedents of the Senate. And now it’s the new regular order.” California Governor Gavin Newsom called the vote “illegal” and vowed to “fight this unconstitutional attack on California in court.”

2. Republicans wiped out rooftop solar in their reconciliation bill

We’re continuing to track the repercussions of the House reconciliation bill that passed early Thursday morning, including its “full-frontal assault on the residential solar business model,” in the words of my colleague Matthew Zeitlin. Though an earlier draft of the bill shortened the availability of the Residential Clean Energy Credit, 25D, for people who purchased home solar systems from 2034 to expiring at the end of this year, Matthew explains that the new language says no credit “shall be allowed under this section for any investment during the taxable year” if the entity claiming the tax credit “rents or leases such property to a third party during such taxable year” and “the lessee would qualify for a credit under section 25D with respect to such property if the lessee owned such property.” That’s “how you kill a business model in legislative text,” Matthew continues. The repercussions were immediate: By midday, shares of Sunrun were already down $37.5%, an erasure of almost $1 billion.

3. BYD outsells Tesla in Europe

For the first time, BYD has outsold Tesla in Europe. In April, the Chinese automaker sold 7,231 electric vehicles, up 169% from the year prior, while Tesla sold 7,165 EVs, down 49% in the same period, Bloomberg reports based on market research by Jato Dynamics.

As we covered in AM earlier this month, the first quarter of 2025 was the second-best month ever for BEV sales in the European Union, despite “the name Tesla [becoming] toxic for so many, limiting its appeal,” Clean Technica wrote at the time. But while BYD marked a milestone in beating the American automaker, it remained in the 10th spot overall for electric vehicle sales, with Volkswagen the clear winner for the month with 23,514 sales. But BYD is “about to reinforce its EV lineup in Europe with the Dolphin Surf, a fully electric hatchback that will sell for” around $22,700 in Germany until the end of June, Bloomberg writes.

4. NOAA predicts above-average hurricane season

NOAA

The National Oceanic and Atmospheric Administration released its forecast for the 2025 Atlantic hurricane season, with a higher estimated upper limit for named storms than earlier predictions from private forecasters. According to NOAA, we can expect between 13 and 19 named storms this year, of which six to 10 could become hurricanes and three to five could develop into major Category 3 or higher hurricanes. That puts the season on track to be more active than the average Atlantic hurricane season, when 14 named storms, seven hurricanes, and three major hurricanes can be expected.

Private forecasters also rely on NOAA data to inform their predictions, but arrived at slightly different conclusions. Colorado State University’s Department of Atmospheric Sciences forecasts 17 named storms for 2025, while AccuWeather predicts 13 to 18 named storms. Though the Atlantic has cooled slightly from its historic highs last year, it is still warmer than usual — part of what is spurring the above-average estimates for the season. Still, as I’ve reported, there are lingering concerns about the reliability of NOAA’s data in future years as the agency hemorrhages the personnel who repair the sensors that monitor sea temperatures or run quality control on the data.

5. Microsoft signs low-carbon cement purchase agreement with Sublime

Microsoft announced its commitment to purchase nearly 623,000 metric tons of low-carbon cement from the startup Sublime Systems on Thursday. The contract, which runs over a six- to nine-year period, is intended to “reduce emissions — both at Microsoft and globally,” Jeff Leeper, the vice president of global datacenter construction at Microsoft, said in a press release about the deal. The company aims to use the cement on its construction projects “when geographically possible,” including incorporating it in data centers, office buildings, and other infrastructure. The companies declined to share how much the deal was worth, Bloomberg writes.

My colleague Emily Pontecorvo profiled Sublime earlier this year, noting that cement is a significant source of carbon emissions — 8% of the global total — due to a chemical reaction with limestone kilns required for production. But Sublime has “developed a new way to make reactive lime that does not require limestone,” Emily explains. “Instead of heating up rocks in a kiln, they drive the chemical process with electric currents. This enables the company to avoid limestone and use a variety of other raw materials that do not contain carbon to produce lime.” The company is working to construct its first 30,000-ton commercial plant, which is expected to be completed in 2027.

THE KICKER

Pakistan imported 22 gigawatts of solar panels in 2024, more than the entire country of Canada. “That’s not a typo or a spreadsheet rounding error. That’s the kind of number that turns heads at IEA meetings and makes policy analysts double-check their databases,” Clean Technica writes.