ClimateTech Startups funded by Y Combinator (YC) 2026

China and Russia control the world’s critical minerals. We can produce Titanium, Magnesium, Aluminum, Zirconium & Hafnium in the U.S. more profitably than any existing process, and carbon neutrally via co-production. Carbochlorination is the primary process for producing critical metals like titanium, hafnium, and zirconium, and was once the standard for magnesium. The problem: conventional carbochlorination relies on purchasing carbon feedstocks, wastes valuable byproducts, and is highly CO₂-intensive. Duranium changes this with a novel reactor that recycles CO₂ emissions back into feedstock (CO) while generating a valuable co-product (bleaching agents). This closed loop slashes emissions and delivers Chinese-level metal pricing without subsidies — unlocking the full potential of carbochlorination for U.S. critical mineral production.

Astro finds and buys land for new renewable energy projects, secures grid connections at minimal cost, and sells these development-ready projects to larger energy companies. Founded by Alex Fuster, a former Citadel energy trader, Astro's AI models identify profitable grid connections that eliminate the surprise costs causing 80-90% of renewable projects to fail. With the U.S. needing 2,000 gigawatts of new power generation by 2035 for AI data centers and electrification, Astro unlocks development opportunities that traditional methods consistently miss.

E-waste recycling facilities spend most of their time and effort sifting through discarded electronics, searching for valuable devices, refurbishing them, and reselling them in second-hand markets. Our first product is an AI-enabled robotic system that integrates with these facilities to assess and refurbish hundreds of laptops a day without any human intervention. The system tests laptops, wipes their hard drives, photographs them, and posts them on online marketplaces for resale, regardless of model, manufacturer, or operating system.

Rewbi uses AI to optimize grid-connected battery storage. We generate revenue by charging when electricity is cheap and discharging when electricity is expensive. We rent battery storage for a fixed fee per month, and we earn 2x that fee in monthly revenue by dispatching the battery optimally. Today, power companies use human traders to manually track grid conditions and update the battery’s dispatch schedule. However batteries can adjust their power output 100x faster than traditional power generation (e.g. hydro, coal, nuclear, gas), with the ability to go from full-speed charging to full speed discharging in under a minute. Electricity prices change every 5 minutes, often by 300% or more. Our AI better tracks 100s of live inputs, and it makes decisions faster than a human operator (with lower overhead!), improving revenue 2x.

We build underwater data centers to cut power usage by up to 30%, operating GPUs cheaper and more sustainably. Our 1 MW capsule is being tested underwater in the SF Bay

Bluedot makes EV charging payment easier and simplifies expense management for drivers and fleets. They're growing 40-45% weekly and made $110K GMV last week. Over 50% of vehicles sold will be electric by 2030. The payments management infrastructure for EV charging and the expenses doesn’t exist at the moment. The founders operated 100+ EV charging stations, worked in companies like Zipcar, Bosch, and Mercedes, and faced this problem through their own experiences. They built a team with a strong fintech background and publicly launched their Bluedot card on Dec 14th, 2022. Bluedot has raised their pre-seed from Y Combinator, Axel Springer, Porsche, Ford, TechNexus, DRF, and Pritchard Automotive.

Founded in 2022, Atmeto was started as a place to develop and apply machine learning to solve the world's biggest problem—climate change. Our current priority is getting the grid to run on 100% clean energy, which is currently limited by battery storage (specifically, the algorithms that control them). We're redefining these algorithms to unlock gigawatts of untapped energy storage capacity, enabling the grid to run on more clean energy from wind and solar.

We offer no-money-down installations that generate free money for homeowners from day one. We are digitalizing the whole process of going solar. Instead of using traditional forms and leaving it up to customers to fill them, we use technology to take all that burden off our customers plate. We only ask for an address and offer free instant quotes.

Nira is a map tool, built for renewable energy developers, that shows available capacity at every interconnection point on the electrical grid. Customers like AES and Cypress Creek use Nira to find the most profitable points on the grid to site new projects.

Wand Solar enables Solar Revenue for Income Properties owners. By empowering landlords to sell solar energy directly to tenants, we make it a no-brainer for landlords to adopt solar energy.

Birch Biosciences engineers enzymes for plastic recycling using synthetic biology and machine learning. Our enzymes function as high performance “molecular scissors” that efficiently break down plastic polymers into chemical building blocks that can be used to manufacture high quality recycled plastic products. Today, plastic manufacturing is unsustainable and a major driver of climate change. Birch Biosciences is developing an economical end-to-end plastic recycling process that reduces carbon emissions by 70% and enables a circular plastic economy.

Impossible mining is building underwater robotics vehicles which collect battery metals from the seabed without harming the environment. We have $500M+ in off-take LoI’s and have signed a partnership with a global offshore logistics company which holds a seabed mining exploration permit. We have also built the 1st PoC underwater robotic arm. Polymetallic nodules are rocks which are rich in critical battery metals. Specially nickel, cobalt, manganese and copper. These metals are the the most expensive part of EVs.

Waterplan is the world’s leading climate platform to measure, respond, report, and monitor companies increasingly changing climate water risk. Customers include multinational companies like Coca-Cola, Diageo, Colgate & Ab InBev. The platform combines companies’ operational data with local water satellite imagery to provide a continuously updated financial assessment of water risk. Based on that, it offers tailored mitigation and adaptation opportunities, from conventional infrastructure to nature-based solutions. The company was founded by a team of tech and water 2nd-time entrepreneurs with two exits and almost ten years of experience working for Fortune 500 companies in water projects. Early investors include YCombinator, Giant Ventures, David Helgason, Leonardo DiCaprio, Richard Branson's family, Manu Ginobili, among others waterplan.com

Imagine a world without chocolate. Horrifying, right? But the supply of cocoa is endangered and chocolate is as bad as meat for our planet. We make future-proof chocolate using precision fermentation. Doing this, our chocolate is 10x more sustainable and 20% cheaper than conventional chocolate. In order to mimic the organoleptic properties of chocolate (tender, smoothly melting taste release) we are working on the flavor itself but also on replacing the cocoa butter. 55 Mio lbs of chocolate are consumed every day. By 2035 we will substitute a big chunk of it through our sustainable chocolate. In addition, we are working on extending our technology platform to additional ingredients such as palm oil.

We are food-tech company. We developed proprietary protein texturing technology that enables us to produce plant-based whole cuts. Our vision is to produce a variety of meat products and match animal derived counterparts by taste, price and convenience. We want to accelerate transition of meat industry into a more sustainable future - by 2030 we want to cut meat consumption in half.

We're building carbon capture for trains and trucks. We generate revenue for railroads and trucking companies by extracting, purifying, and selling CO2 from their exhaust. Our technology can capture up to 90% of the CO2 in the vehicle's exhaust while reducing soot, particulate matter, and NOx. We've partnered with Union Pacific, Norfolk Southern, Ryder, and Werner, and raised $117 million from Lowercarbon Capital, Valor Equity Partners, Union Square Ventures, and Y Combinator.

Nobell Foods is creating cheese and other dairy products from plant-derived dairy proteins for the 99% of people who are unwilling to compromise on taste and price.

Culdesac designs, builds, and manages walkable communities. Culdesac is a real estate developer and property manager. We build neighborhoods that embrace community, open space, and mobility. We offer residential units at a variety of price points integrated with local retail, commercial uses, and open space for nature and public plazas. Our communities prioritize biking, walking, and transit over cars and parking. We partner with leading mobility companies to deliver convenient and affordable transportation services. This creates a vibrant urban lifestyle without the need for a private vehicle. Read more here > https://medium.com/culdesac/introducing-culdesac-3fbfe7c4219c

Valo build modular integrated hydrofoil systems for the worlds boatbuilders, allowing them to create fast, clean and quiet flying vessels that consume 15x less energy.

Solugen is decarbonizing the chemistry of everyday life with enzymes and innovative metal catalysts. Our new to the world Bioforge platform technology can produce high value chemical goods that are biobased and carbon negative, at cost on par with current technologies. We are making sustainable chemistry accessible to all living things, to ensure a prosperous world exists for generations.

Validere is a measurement, reporting, and verification (MRV) SaaS company that helps energy organizations transform disconnected, incomplete data into clear and immediately actionable pathways to financial and environmental value. Over 50 of North America's leading energy companies rely on Validere's technology and multidisciplinary experts to understand their physical and environmental commodities and navigate an increasingly complex environment with clarity and ease. Validere is on a mission to better human prosperity by making the energy supply chain efficient and sustainable. The company has offices in Houston, Calgary, and Toronto.

Pina Earth is building a suite of digital tools for data collection, monitoring, and certification of forest carbon projects. EU forests are at high risk due to climate change. With Pina Earth, forest owners can start high-quality carbon projects on their properties and use the new income stream to prepare their forests for a changing climate. Pina Earth and Tree.ly recently joined forces to create Europe's leading forest carbon platform: https://tech.eu/2025/07/29/pina-earth-and-treely-merge-to-create-europes-largest-forest-carbon-platform/

Software that simplifies electric grid forecasting and operations. Clients--hard assets like wind, solar and energy storage--get timely, unbiased information to improve revenues, reduce risk, and maximize the profitability of every megawatt. Gaiascope also manages a quant fund trading electricity; with this fund, the company builds additional credibility with clients and accelerates the continuous improvement of its software.

(acquired by Brondell in 2022) At Nebia we build innovative and impactful products that improve how people use water in their daily lives. Through thoughtful reinvention of everyday interactions, we empower people everywhere to collectively make a greater impact with their most basic daily rituals. We started with the shower. The Nebia shower embodies the highest standards of experience, design, engineering and water and energy use. With water savings up to 70% compared to traditional showers, Nebia was designed to make a meaningful impact without compromising on experience. At the heart of our products is our unwavering dedication to developing groundbreaking sustainable solutions that stand the test of time. Every new iteration is made to solve a complex engineering challenge that has limited innovation for over a century. Our investment in R&D and product development is second only to our investment in the people who are making it possible. After several years working behind the scenes, we are extremely proud of what we have recently achieved: - $10m raised on Kickstarter - Products in 100,000 homes - 500+ million gallons of water saved (c. 2022) - 27 million kWh (27 GWh) of energy (approx. energy to heat 2,700 U.S. homes in one year)