Top Clean Energy Startups in 2027

Aurora Solar develops cloud-based software that enables sophisticated solar PV engineering design, provides workflow management functionality, and facilitates sales and customer acquisition for solar installers and financiers. Our software is used to create over 200,000 solar projects a month across the US and around the world.

Oklo is a California-based company developing clean energy plants to provide emission-free, reliable, and affordable energy using advanced fission. Oklo is a fast-growing startup with a history of reliable funding and milestones for more than 5 years. Oklo’s first product is a microgrid scale powerhouse. The powerhouse can produce clean energy for decades without needing to refuel, and also has the capability to turn nuclear waste into clean energy. Oklo received a Site Use Permit from the U.S Department of Energy, demonstrated fabrication of its fuel, was awarded fuel from the Idaho National Laboratory, and submitted the first accepted advanced fission license application to the regulator. Oklo has been featured in Popular Mechanics, Wired, Architectural Digest, Hyperallergic, POWER Magazine, and has been the subject of a Harvard Business School case, and was featured in the documentary The New Fire, among many other features.

We save building owners money on their energy bills by managing their onsite energy assets (such as battery storage, HVAC controls, solar, cogeneration, and electric vehicles) intelligently and efficiently with our machine learning platform. Our position as a retail electricity provider allows us to unlock value streams to customers currently unavailable to them.

Omnidian’s award-winning teams have been protecting the large-scale residential solar portfolios of our fortune 1000 clients and now - the industry’s leading residential solar protection plan with a 95% performance guarantee is available to homeowners through select elite and premier dealers. in 2017, we were awarded the department of energy sunshot grant, which accelerates the development of highly impactful solar energy technologies.

Commonwealth fusion systems (cfs) was spun out of mit's plasma science and fusion center to leverage the decades of fusion research combined with the innovation and speed of the private sector. supported by the world’s leading investors in breakthrough energy technologies, the cfs team is uniquely positioned to deliver the fastest path to commercial fusion energy. cfs has assembled a world class team that includes experts in magnets, manufacturing and plasma physics dedicated to the mission of delivering clean, limitless fusion power to the world.

At Rhythm Energy, we’re redefining what it means to power a home. Launched in 2021, we help Texans transition to 100% renewable energy through thoughtfully designed products that put customers in control. Our approach combines technology, transparency, and a customer-first mindset to create a smarter, more sustainable energy experience. But what really sets us apart is our people. We’re a multidisciplinary team of builders—engineers, product thinkers, data experts, creatives, and customer advocates—working together to solve complex problems in a simple, human way. We move fast, think independently, and care deeply about the impact of our work. Our mission is straightforward: make clean energy more accessible, intuitive, and valuable for everyday life. If you’re someone who likes building from the ground up, thrives in ambiguity, and wants your work to matter, you’ll fit right in. We’re always looking for people who bring curiosity, ownership, and a bias toward action.

Company Background: Optivolt was founded in 2017 by Rohit Kalyanpur, a Thiel Fellow and recognized leader in the solar industry and startup ecosystem who has built a world-class team of experts from Tesla, Enphase, SolarEdge, Apple, Qualcomm, and with PhD’s from Stanford, Berkeley, and UIUC. Since its inception, Optivolt has successfully raised $25 million and, in 2025 alone, is on track to deliver over 100,000 Balancer units to customers nationwide. With production now scaling, our primary focus is operational excellence and accelerating our growth trajectory. The Problem: Despite its potential, solar supplies just 5% of global energy—limited by fundamental technical barriers. Minor shading can reduce power output by 90%, while systems remain bulky, expensive, time-consuming to install, and prone to failure. Optivolt's Breakthrough: We realized deep integration between solar panels and power electronics unlocks an entirely new design space for innovation. This led us to inventing the Balancer (8 patents issued, 27 pending), an advanced power electronics device which embeds inside solar panels. Balancers work by shuffling power from stronger to weaker zones in the panel to keep power flowing, maximizing energy output and reliability. Performance vs. $8B market leader: • Up to 6x higher power output in real-world conditions • 40% lower equipment cost, 50% faster to install • 4x less failure points, while eliminating hotspots (#1 solar failure mode) Balancers cut the cost of solar by up to 40%, which for the first time, makes solar cheaper than the grid—everywhere. Recognizing the impact, the U.S. Department of Energy is participating in funding of Optivolt’s development.

We have pioneered the focus on creating accessible Electric Vehicle charging platforms and stations through our products, we've assisted a range of individuals, companies and sectors and continue to promote access to EV charging platforms.

Ohmconnect is a software based power plant. Instead of turning on a dirty coal or gas power plant during times of peak demand, Ohmconnect has hundreds of users reduce their electricity. Best part is that instead of paying dirty gas power plants to turn on, ohmconnect can pay its users to turn down. When users sign up, they are told when to reduce their electricity. If they participate, their energy reductions can be sold into the markets as additional generation. Ohmconnect hooks into users' wifi thermostats, electric cars, and smart devices to automate these reductions. Our users are presented with a clean visualization of where their energy is coming from and where their energy is going. For each event that they participate in, they earn Ohmconnect points which can be cashed out at any time.

We aggregate federal and state geospatial datasets and regulatory documents and build AI systems to give project developers and contractors automated spatial intelligence from site selection to permitting to project development across carbon sequestration, geothermal, hydrogen, and minerals projects.