Rep. Sean Casten, D-Ill., accidentally found fame one Thursday afternoon in an obscure world he didn't know existed: "Energy Twitter."

"A lot of my colleagues have achieved social media fame for things other than … tweet threads on the nature of hydrogen," he said in an interview with Utility Dive. 

"OK, so I need to do a brief rant on something hugely important that almost no one cares about. Humor me," the August Twitter thread began. 584 retweets and around 1,500 likes later, the then-freshman Congressman realized that, in fact, a lot of people cared.

"It's an uplifting statement on humanity" to find such a wonky audience in a world like Twitter, where arguments are so often limited to sound bites and "gotcha" moments, the former clean energy executive said. 

Since then, he's become a sought after speaker for clean energy forums, speaking at National Clean Energy Week and an American Council on Renewable Energy (ACORE) conference earlier this year.

"Congressman Sean Casten is an innovative and inspirational public servant," said ACORE President and CEO Gregory Wetstone in an email. "His policy approach is thorough, thoughtful and unabashedly pro-science, and his technological and market expertise have made his twitter explanations of key energy issues a must-read for the industry."

Casten relishes any opportunity to "nerd out" with fellow climate and clean energy enthusiasts. He's been passionate about the climate crisis since college, and calls it the "North Star" that has guided his path. On Capitol Hill, it's given him a particular niche at a critical time for the energy transition and the rising urgency to mitigate climate change. He's able to help disentangle the perspectives of various think tanks, interest groups and Hill staffers for his fellow members of Congress, similar to how they've aided him in understanding issues on healthcare and national security, for example. 

But being the go-to energy guy has also made it clear there is a disconnect on the Hill: "We have a PhD level problem. And Congress is at a 6th grade reading level," he said. Policies like the Green New Deal, which he considers equity policy more than energy policy, represent a "sound bites without substance" problem, while more bipartisan policies don't go far enough in contemplating what is scientifically necessary.

Before he was elected to Congress, he was often told energy policy was too complicated to move at the speed he thought was necessary. But "if we replace that with a narrative that says climate change is far too urgent to get bogged down in complexity, that's just as dangerous," he said.

"We need the complexity, we need the nuance, and we also need to recognize the urgency of this. I'm glad that the Green New Deal has elevated that urgency. I am concerned that it has allowed too many of my colleagues to get into sound bites without substance."

Casten's path to Congress

At the start of his career, Casten believed developing new technologies was the best way to fight rising greenhouse gas emissions, but quickly realized there was a business problem: If a technology isn't economically viable, it won't go anywhere. He took over as president and CEO of a company that focused on the "totally unsexy, but totally unbelievably economic technology" of steam turbine generators, later founding his own company that similarly used recycled thermal energy.

"But along the way we kept realizing that more often than not, even though we had an economically viable proposition, even though we had totally proven technologies, we kept running into state and federal laws that blocked us from getting done what we needed," he said.

That got him involved in policy work and advocacy on Capitol Hill. Friends told him he should run for Congress someday, but he never took those comments too seriously until President Donald Trump was elected in 2016.

Trump, for Casten, represented a threat to his life's work and the science that had driven his path since he was in his 20s. "Here's this guy who is completely incapable of dealing with truth and much less science," he said of Trump. 

Casten beat the incumbent Republican representative in 2018, flipping the seat blue for the first time since the mid-1970s, according to the Chicago Sun Times. In 2020, he won his seat again, beating Republican challenger Jeanne Ives.

During her campaign, Ives accused Casten of using his congressional seat to advance clean energy to benefit his business interests, pointing out his stake in biomass company Greenleaf Power. Casten disclosed a $250,001 to $500,000 stake in Greenleaf Power LLC, CQ Roll Call reported earlier this year. His office did not respond to request for comment, but a spokesperson told Roll Call it was a "non-controlling, minority stake."

Casten's proudest achievement of his first term in Congress is the House Select Committee on the Climate Crisis proposal — a 547 page staff report that outlines a U.S. path toward net-zero carbon emissions economy-wide by 2050.

"Number one, we acknowledged what was scientifically necessary. Number two, we put forth all of the legislation that was consistent with that goal that's been introduced in the 116th Congress," he said. "We then calculated the impact. And then we had the honesty to say this is not enough" while recommending other ways to get the U.S. all the way there. "When does that ever happen in Congress?" he said. 

Republicans at the time were frustrated by what they saw as the report's partisan bent, though they acknowledged a lot of its proposals could get bipartisan backing. Other climate policy analysts called the report "the most comprehensive plan that Congress has ever put forward."

The House and Senate have both made progress on other legislation this year as well — the House passed the Moving Forward Act and the Senate made progress on the Energy Innovation Act. But neither bill reaches the scale of what is needed to be done to prevent the worst impacts of climate change, said Casten.

Politically possible versus scientifically necessary

Casten is seen as a moderate Democrat by most on the Hill — he won his previously Republican district by less than 20,000 votes this year, and beat the incumbent by a similar margin in 2018. Conservatives in the clean energy space hope that he can become a bridge between Republicans and Democrats on climate issues.

"The Democratic Party overall ... would be smart to take his lead or hear him out about what can be done, and really use him to reach across the aisle and work with Republicans because he speaks a business language and an economic language," said Heather Reams, executive director of Citizens for Responsible Energy Solutions. "And I think that would be helpful for Republicans to understand the economics behind deep decarbonization."

But Casten sees a priority problem with legislation like the Energy Innovation Act, which comprises over 50 bipartisan energy bills reported to the Senate in 2019 and is focused on research and development for existing and emerging clean energy technologies. That and other proposed or passed bills prioritize bipartisanship over what is necessary, said Casten.

"The question you have to ask is 'Is anything that we are doing consistent with what is scientifically necessary?'" he said. "If I told you that gravity is real and if you don't move your car, that tree is going to fall on it and you said, 'Well, I'm going to move my car a foot,' don't come asking for prayers when the tree hits your car."

Climate policy does need innovation, he said, but it also needs a lot more. The power sector needs to cut the amount of energy used in half, the federal government needs to invest in massive research and development to cut emissions from difficult-to-decarbonize sectors and get rid of fossil fuel subsidies entirely to "level the playing field" for energy resources. On this matter, Casten takes issue with actions under the Federal Energy Regulatory Commission's approach, which prioritized the removal of state-sponsored subsidies for clean resources from wholesale markets under former Chair Neil Chatterjee.

"I'm quite disappointed by what FERC has done. And it's unfortunate because I like Chairman Chatterjee as a person. ... But he has essentially taken an approach to climate that's sort of like Trump's approach to COVID," said Casten. "Whatever you do, don't … leave the states to figure it out on their own and then create tension between the states when they try to figure out how to do what needs to be done."

Casten hopes that under Biden, climate will become more of a priority than it has been, he told an ACORE audience, but he also said prioritizing what's politically feasible will continue to be a mistake.

"I want to talk basically about what I think energy policy needs to be in the Biden administration and … while I'm happy in your questions to talk about how that might be constrained by politics, I don't want to lead with that," he said, "Because I think, if we're really honest, for 30 years, we have prioritized the politically possible over the scientifically necessary and we do not have another 30 years to wait."