Despite a comparatively weaker year for cleantech equity funding in 2024, several American CleanTech startups managed to secure record-breaking capital. This article spotlights the largest fundraises among those companies leading the charge toward a sustainable energy future. From Intersect Power’s innovative data center partnerships to Pacific Fusion’s game-changing approach to pulsed magnetic inertial fusion, these ventures defy the downturn by attracting the backing of climate-focused funds, strategic corporate investors, and mainstream venture capitalists alike. The shift to big-ticket debt financings and mega-rounds reflect both a maturing clean energy sector and investors’ readiness to fund ambitious hardware- and infrastructure-heavy projects. Taken together, these massive fundraises signal an ongoing commitment to building scalable solutions and setting the stage for a cleaner, greener tomorrow.

Intersect Power

Intersect Power, a leading clean energy company, focuses on developing and operating large-scale renewable energy infrastructure to deliver low-carbon electricity, fuels, and related products. With $1.827 billion in equity funding, the company has positioned itself as a key player in the transition to a sustainable energy future. Known for its innovative approach, Intersect Power recently entered a strategic partnership with Google and TPG Rise Climate to co-locate data centers with renewable energy generation facilities. This groundbreaking collaboration aims to add gigawatts of new data center capacity across the U.S. while catalyzing $20 billion in renewable power infrastructure investments by the end of the decade, reinforcing Intersect Power’s commitment to driving impactful, scalable solutions for decarbonization.

Sila

Sila, an innovative battery materials company specializing in high-energy-density lithium-ion batteries for electric vehicles, is transforming the future of energy storage. Founded in 2011 by Gleb Yushin, Alex Jacobs, and Gene Berdichevsky—who led battery development for the Tesla Roadster—the company focuses on developing advanced lithium-silicon technology. By replacing traditional graphite anodes with silicon-dominant composites, Sila significantly enhances energy density, improving battery efficiency for a range of applications. In 2024, Sila secured a total of $1.255 billion in equity funding, marking a major milestone in its growth. This funding underscores the company’s leadership in the battery materials industry and its commitment to scaling production and accelerating the transition to sustainable energy solutions.

Form Energy

Form Energy, an innovative American energy storage company founded in 2017 by Mateo Jaramillo, Yet-Ming Chiang, Ted Wiley, William Woodford, and Marco Ferrara, is revolutionizing long-duration energy storage. The company focuses on developing cost-effective, multi-day energy storage systems to support a fully renewable electric grid. Its flagship product, a rechargeable iron-air battery, can store electricity for up to 100 hours at a fraction of the cost of traditional lithium-ion batteries. In 2024, Form Energy raised $1.220 billion in equity funding, further fueling its mission to make renewable energy reliable year-round and accelerate the transition to a sustainable energy future.

Beta Technologies

Beta Technologies, an aerospace manufacturer based in South Burlington, Vermont, has raised a total of $1.204 billion in equity funding in 2024. Founded in 2017 by Kyle Clark, the company specializes in electric vertical takeoff and landing (eVTOL) and electric conventional takeoff and landing (eCTOL) aircraft. Beta Technologies serves a variety of sectors, including cargo, medical transport, passenger services, and military aviation. The company has also developed a network of charging stations for its electric aircraft and other vehicles. With over 650 employees in 2024, Beta Technologies is a leader in the growing electric aviation industry, with plans for further expansion in both civilian and military sectors.

Ascend Elements

In 2024, Beta Technologies, an aerospace manufacturer specializing in electric vertical takeoff and landing (eVTOL) and electric conventional takeoff and landing (eCTOL) aircraft, secured $1.204 billion in equity funding. Founded in 2017, the company is leading the charge in electric aviation, with applications across cargo, medical transport, passenger services, and military sectors. Beta Technologies has also developed a network of charging stations to support its electric aircraft and other vehicles, positioning the company as a key player in the clean aviation industry.

Pacific Fusion

Pacific Fusion, a private company founded in 2023 and based in Fremont, California, raised $900 million in equity funding in 2024. The company is focused on developing renewable energy solutions, with an emphasis on affordable fusion power inspired by nature. Pacific Fusion emerged from stealth mode in late 2024, announcing plans to create a pulsed magnetic fusion system capable of achieving net facility gain, where energy output exceeds input. This ambitious project aims to provide abundant, clean, and affordable energy through advanced fusion technology.

Twelve

Twelve, a California-based carbon transformation company founded in 2015, raised $798 million in equity funding in 2024. The company specializes in converting captured carbon dioxide into valuable chemicals, materials, and fuels, aiming to reduce reliance on fossil fuels and combat climate change. In September 2024, Twelve secured $645 million in funding to scale up its production of sustainable aviation fuel (SAF) from CO2, including $400 million in project equity led by TPG Rise Climate and $200 million in Series C financing. The company’s first SAF plant, AirPlant One, is under development in Moses Lake, Washington, with production expected to begin in 2025, targeting up to 90% lower lifecycle emissions than conventional jet fuel.

Redaptive

Redaptive, an Energy-as-a-Service (EaaS) provider based in Denver, Colorado, raised $526 million in equity funding, with a significant $100 million investment secured in October 2024 from the Canada Pension Plan Investment Board (CPP Investments). Founded in 2015, Redaptive helps large commercial and industrial organizations achieve sustainability and energy efficiency goals through a shared savings model, offering services such as diagnostics, project development, funding, and energy efficiency monitoring. The latest funding will help scale its projects and support its growing customer base in reaching net-zero emissions targets, building on a prior $200 million investment from CPP Investments in 2022.

Monarch Tractor

Monarch Tractor, a company pioneering fully electric, autonomous tractors, raised $214 million in equity funding in 2024. Founded in 2017 and headquartered in Livermore, California, Monarch Tractor is dedicated to transforming agriculture with sustainable technology, aiming to enhance productivity, safety, and address labor shortages through automation. The company’s innovative electric, driver-optional tractors leverage artificial intelligence to improve farming practices while reducing environmental impact. Monarch has expanded its R&D efforts and formed partnerships to further advance its mission of making farming more economically viable and environmentally sustainable.

Heirloom

Heirloom Carbon Technologies, a leader in Direct Air Capture (DAC) technology, raised $203 million in equity funding in 2024. Founded in 2020, the company focuses on efficiently removing carbon dioxide (CO2) from the atmosphere using limestone as a primary material. Heirloom aims to capture 1 billion tons of CO2 annually by 2035, contributing significantly to global emission reduction targets. In December 2024, Heirloom secured $150 million in a Series B funding round, co-led by Future Positive and Lowercarbon Capital, with participation from investors like Japan Airlines, Mitsubishi Corporation, and Siemens Financial Services.

While data confirms that overall cleantech funding saw a dip in 2024, the record raises by groundbreaking companies underscore a continued appetite for transformative solutions. Going into 2025, investors and startups face a shifting policy landscape and evolving market conditions, yet the sustained momentum behind large later-stage deals suggests a robust pipeline of innovation. If the past year’s headline fundraises are any indication, the American CleanTech ecosystem remains poised to deliver on the promise of greener power, cleaner transportation, and a viable path toward net-zero emissions.