Cleantech companies endeavor to create pragmatic solutions against climate change. The sector pulled in global investments of over $130 billion in 2024. This growth is propelled not just by private capital but also by considerable government support across the globe, for example, in the U.S., Europe, and Asia.
Government programs provide incentives that allow the scaling of these startups. In the U.S., the Inflation Reduction Act provides credit for clean energy and manufacturing. The EU Innovation Fund finances large-scale decarbonization projects. And Japan's Green Innovation Fund gives a push to low-carbon technology development.
In other words, these initiatives worldwide are ensuring enough money and sufficient market pressure to help take these ideas from the lab environment and into real-world use.
The companies featured in this list are not just making claims; they are producing Hydrogen, storing renewable energy over long periods, making bio-based materials, and installing systems for removing or controlling harmful emissions. These are not just technologies for the future; they are making a real-world impact today.
Here are 25 cleantech startups working to meet the demands and needs of everyone, contributing to a cleaner and greener Earth. Each was selected because of real progress, relevance to 2025, and strong potential to keep making an impact in the years ahead.
Cleantech, or clean technology, refers to the development of new and innovative ideas and tools that help the planet. It stands for generating energy, products, and systems that waste less, pollute less, and use resources better. Examples include renewable energy, improved batteries, eco-friendly materials, and processes to recycle or reduce waste.
Worth over $900 billion in 2024, the cleantech sector still holds fast to its record-breaking expansion streak. One of the notable examples is Climeworks, which is a Swiss startup that sucks carbon dioxide directly from the air and then stores it underground. This is a tangible way for businesses to reduce their ecological footprint.
Cleantech is a big field; each head addresses an environmental problem in different ways. Some produce clean energy, others reduce waste, and some treat existing pollution. When seen together, these solutions form a potent range that can save the Earth.
One significant area is renewable energy — solar, wind, and hydropower — which provides cleaner ways to establish homes, businesses, and road transport. Greentech deals with eco-conscious products and environmentally friendly processes. Energy storage keeps things from AI: advanced batteries even store your renewable energy when the sun doesn't shine, or the wind won't blow.
Other fields include wastewater treatment to mitigate risks to human and environmental health by safe disposal of waste beyond water, air quality control, which limits harmful gases and pollutants from reaching our breathing medium. They also do carbon capture, sustainable agriculture, and recycling innovations, geared to give us and our future generations a cleaner, healthier world.
Top cleantech startups like Fervo Energy, Electric Hydrogen, e-Zinc, HiiROC, Hydrogenious Technologies, Hystar, and CarbonBuilt are developing practical solutions for renewable energy, green hydrogen, energy storage, and low-carbon construction.
These companies focus on reducing emissions, improving efficiency, and enabling scalable clean energy adoption across industries in the US and Europe, making sustainable technologies more accessible and commercially viable in 2025.
Form Energy is a US-based startup that is developing an entirely new battery design that can store electricity for a duration as long as 100 hours. If you have ever wondered about the technology behind keeping the lights on when the sun is not shining or the wind is blowing, such is the technology.
Instead of lithium-ion cells, the batteries made by Form Energy operate on iron-air chemistry. In simple terms, they "inhale and exhale" oxygen, changing iron to rust and back again to store and release energy. This technology is way cheaper and safer compared to many battery technologies out there.
The company had managed to raise over $800 million from investors like Breakthrough Energy Ventures and got its batteries into a utility partnership with Public Service Company of Colorado and Xcel Energy. With large-scale manufacturing moving into operation, this system, which hides power grids, may be made visible within a couple of years.
Amogy is making clean fuel from ammonia for heavy-duty transport. This technology offers a way for ships, trucks, and large industrial machines that aren't easily converted to battery power to be powered without releasing carbon dioxide into the air, thereby significantly reducing carbon emissions in the transportation sector.
The company's technology cracks ammonia into Hydrogen that is then fed into fuel cells. In contrast, this is completely devoid of carbon emissions and offers much greater densification of energy than batteries, rendering it suitable for large-scale, long-distance use.
In 2024, Amogy announced the success of a test for an ammonia-powered tugboat in New York: a first-of-its-kind demonstration in the U.S. So the day isn't far off for ammonia being used to fuel more ships and industrial vehicles.
Geothermal energy involves harnessing heat from deep underground to generate electricity. Fervo Energy has developed a method to achieve this in previously inaccessible locations. They use drilling methods borrowed from the oil and gas industry to reach hot rocks and turn that heat into steady, clean power.
In 2024, Fervo's Project Red in Nevada started sending electricity straight to Google's data centers — enough to keep thousands of computers running all day and night. Unlike solar or wind, geothermal doesn't depend on the weather so that it can deliver power 24/7.
Fervo's technology uses fiber-optic cables to measure underground heat very precisely. This helps them choose the best drilling spots and keep costs lower. If it scales up, there's a good chance geothermal could be powering more homes, offices, and data centers soon.
Energy Dome, based in Milan, has one precise aim — to make renewable energy available any time, day or night. They use a "CO₂ Battery" that stores extra power from solar or wind and releases it when it's needed.
The system works by compressing carbon dioxide into a liquid when there's extra energy, then turning it back into gas to drive a turbine and make electricity. It's made from common materials like steel, water, and CO₂, so it can be built and maintained in many places.
Recently, the company secured about €55 million in new funding and partnered with Google to bring its storage technology to more markets. They're also building a large facility in Sardinia on the site of an old oil power plant, showing how clean energy can replace fossil fuels in practice.
Raptor Maps builds software that helps solar power companies keep their systems running at peak performance. Their platform collects and organizes data from drones, sensors, and on-site inspections to spot problems — from faulty panels to overgrown plants — before they cut into energy production.
Instead of sending people to check thousands of panels manually, Raptor Maps uses drone images and innovative software to scan entire solar farms quickly and accurately. It creates a detailed "digital twin" of each site, making it easier for operators to track changes, fix issues faster, and get more energy out of every panel.
The company has expanded its technology to support solar projects in over 50 countries. With more than 150 gigawatts of solar capacity under its watch, Raptor Maps is helping operators keep renewable power flowing more reliably and affordably.
If you drive an EV, you've probably wondered what would happen if everyone plugged in at the same time. That's where WeaveGrid comes in. They've built software that helps cars charge when the grid can handle it — and when it's cheaper or powered by clean energy.
Their system communicates with your car, the charger, and the utility to determine the optimal time to charge your battery. Sometimes, it can even send power back to the grid if it's needed. You plug in, and it takes care of the rest.
In the last year, they teamed up with Toyota, Hyundai, Kia, and ChargePoint, and now work with utilities serving almost half of all EVs in the U.S. Basically, they're making sure your EV habit doesn't overload the grid.
Dandelion Energy installs geothermal systems that pull warmth from the Earth in winter and send heat back underground in summer. It's clean, quiet, and can cut your home's carbon emissions by up to 75%.
Instead of burning fuel, their system runs on a super-efficient heat pump connected to pipes about 500 feet down. You still get heating, cooling, and hot water — just without the pollution or the constant maintenance. And thanks to tax credits and rebates, it can cost less than you think.
This past year, they raised $40 million from big names like Google Ventures. They teamed up with homebuilder Lennar to put geothermal into over 1,500 new homes in Colorado. Over time, those families are expected to save about $30 million on energy bills.
In the long-duration energy storage space, e-Zinc is taking a different route from the usual lithium-ion crowd. Their zinc-air batteries can hold renewable energy for days, making solar and wind far more reliable when the weather doesn't cooperate.
Instead of relying on costly, resource-intensive metals, e-Zinc stores energy by turning electricity into solid zinc during charging, then reversing the process to release power. Zinc is cheap, recyclable, and works in extreme heat or cold — which means these batteries can go where others can't.
They're now teaming with Toyota Tsusho and the California Energy Commission on significant projects. Their goal is to make multi-day, clean energy storage not just a technical possibility, but an everyday reality.
Concrete is used all over the world, but tremendous carbon emissions are generated in its production processes. The Calgary-based Carbon Upcycling Technologies takes CO₂ that escapes from factories and converts it into ingredients to make concrete stronger and cleaner.
They mix the captured carbon dioxide with industrial leftover materials, thereby locking the carbon within the concrete itself. The process fits straight into the lined cement equipment they already have, so the companies need not modify their equipment in any way.
They were recently registered as certified B Corps, expanded into the U.S. and U.K., and are now developing the largest carbon reuse project at a cement plant. Alongside partners like CRH and Cemex, they are teaching the industry how to reduce emissions but without compromising performance.
Every EV, wind turbine, and solar battery needs critical metals like nickel and cobalt—but instead of digging them out of the ground, Nth Cycle gives these metals a second life. From their base in Massachusetts, they've created a clean, electricity-and-water-powered system that pulls high-quality metals from old batteries, scrap, and mining leftovers.
Their tech, nicknamed "The Oyster," ditches toxic chemicals and extreme heat for a gentler, modular setup that can pop up right where the metals are. The result? Battery-grade materials with over 90% fewer emissions than traditional refining.
In 2025, they scored $44M in funding and launched their first big facility in Ohio. Now, they're gearing up to bring this more innovative recycling approach across the U.S. and Europe—keeping valuable metals in circulation and mining waste out of the picture.
Redwood Materials takes old batteries from electric cars, electronics, and factory leftovers, and pulls out more than 95% of the valuable metals inside—like lithium, nickel, and cobalt. Then, they turn those metals into materials for brand-new batteries. Suppose a battery still has some life left.
In that case, they give it a "second life" in energy storage before being recycled completely. Their recycling process uses significantly less energy and water than mining, so every battery you send their way helps reduce pollution and keeps valuable materials in use instead of going to waste.
Sulapac, from Finland, makes materials that work like plastic but aren't plastic at all. It's made from wood chips, plants, and minerals, and when you're done with it, it breaks down naturally—no microplastics left behind. Even better, factories can make it using the same machines they already use for regular plastic.
Big names like Chanel and Lumene are already using it, and over 100 manufacturers worldwide have joined in. You can reuse it, recycle it, or let it safely return to nature. It's cutting plastic waste and lowering carbon emissions.
The Canadian startup Li-Cycle recovers valuable metals such as lithium, cobalt, and nickel from old lithium-ion batteries of all kinds, including EVs and laptops. Instead of melting them down, the company employs a special process that uses minimal heat and water, thereby making the process safer and cleaner, while also maximizing the recovery of materials for new batteries.
In 2025, Glencore, one of the world's largest mining giants, acquired it to establish an end-to-end recyclability footprint for its operations. Despite the financial bumps, Li-Cycle facilities in New York and Arizona must be operational in turning waste batteries into a steady supply of material for the clean energy realm.
Climeworks is a Swiss company that has been removing CO₂ straight from the air since 2009. Their goal is to capture carbon safely and permanently to fight climate change.
They use modular "air filter" units powered by renewable energy. The captured CO₂ is stored underground, where it turns into stone or is reused. Their plants already remove thousands of tons per year, and bigger, more efficient systems are on the way, backed by corporate and government support.
Skeleton Technologies, founded in 2009, builds energy storage systems that charge quickly, last a long time, and deliver strong power when needed. Their technology uses advanced super-fast charging systems instead of regular batteries.
By 2025, Skeleton's systems will be used in cars, trains, factories, and clean energy projects. They help cut fuel use and lower carbon emissions, making energy use brighter and cleaner across many industries.
CarbonCure Technologies is a company that reduces concrete's carbon footprint by turning captured CO₂ into a permanent part of the concrete itself. Since 2012, they've been helping concrete plants store carbon safely while keeping their mixes strong.
Their technology injects CO₂ during mixing, where it mineralizes into calcium carbonate. This locks away carbon forever and lets producers use less cement without losing quality. The system fits into existing plants easily and is already used in over 400 plants worldwide, including projects like Amazon HQ2, backed by investors like Microsoft and Amazon Climate Fund.
NAWA Technologies deals with ultra-fast and high-power energy-storage devices using advanced carbon nanotechnology. Its products, like NAWACap ultracapacitors, charge and discharge energy much faster than conventional batteries and last longer; therefore, these devices find uses in electric vehicles, smart grids, aerospace, and defense.
They have partnered with SotaTek to scale technology and market reach. The company is also exploring energy storage in structural materials, such as car bodies and airplane wings, for lighter and more efficient vehicles.
Imagine you could build with concrete that removes CO2 from the air instead of adding more. That's what CarbiCrete does. They skip the usual cement, use steel factory leftovers, and trap carbon in the concrete as it hardens. The result? Strong, eco-friendly concrete that helps fight climate change.
CarbiCrete's system can be added to existing plants, so companies can start making greener concrete right away. They've teamed up with big names like Meta and Canadian block makers to scale this fast. Every time you use it, you're helping cut emissions while turning waste into something useful.
Krajete is an innovative Austrian cleantech company. The firm delivers C02 control, NOx removal and control, and SOx removal with nature-inspired technology: mineral adsorbers that act like reusable “sponges” for pollutants, and micro-organisms that convert CO₂ and hydrogen into pipeline-grade methane. The result supports the circular economy—turning emissions into useful inputs instead of waste.
Krajete’s main clients are heavy emitters that need reliable, low-maintenance solutions: oil & gas, mining, power generation, chemicals, automotive, metals, and shipping. By regenerating adsorbers and valorising captured gases, these clients can meet emissions targets, cut consumables, and reduce operative expenses while creating new value from what used to be pollution.
Otovo is a fast-growing European clean technology company, assisting homeowners in switching to solar energy. From their website, you enter your address to quickly calculate the solar potential of your rooftop and receive multiple competing offers from local trusted installers.
What sets Otovo apart is that it is not a solar seller itself but instead acts as a platform that connects its users with the best installers. You can choose to compete on price and pay with utmost ease. With over 500 installers in 13 European countries and thousands of successful installation projects under its belt, Otovo is making solar a reality for many across Europe by making green energy straightforward, affordable, and easily accessible.
Electric Hydrogen produces green Hydrogen for heavy industries such as steel, fertilizer, and shipping. Their massive 100 MW electrolyzers split water using renewable electricity and can be installed on-site, cutting costs. With a 1.2 GW/year factory in Massachusetts and investor support, they aim to replace fossil fuels with clean Hydrogen in key industrial sectors.
HiiROC is a British company that makes clean Hydrogen without CO2. Their innovative process turns methane into Hydrogen and solid carbon, using less energy than usual. It works for small or big setups, helping you get green Hydrogen for industry, transport, or power, with partners like Siemens and Cemex.
Think of Hydrogenious Technologies as making Hydrogen as easy to handle as a regular liquid fuel. Instead of dealing with dangerous high-pressure tanks or super-cold storage, they lock Hydrogen into a safe liquid carrier. This means you can store, transport, and use green Hydrogen anywhere—industries, refueling stations, or long-distance shipping—without the usual risks.
Hystar is making green Hydrogen smarter and more efficient. Their innovative PEM electrolysers use thinner membranes and clever water and air designs to produce more Hydrogen with less electricity. Compact, modular, and scalable, their systems can fit small setups or massive industrial projects. By cutting costs and boosting safety, Hystar is helping you access clean Hydrogen for a greener future.
CarbonBuilt makes concrete that's good for the planet. They capture CO2 from factories and incorporate it into the concrete, making it stronger and significantly cleaner than regular concrete. Their process can even remove more carbon than it creates, helping buildings and roads fight climate change..
Startups like Fervo Energy, Electric Hydrogen, and e-Zinc demonstrate that clean energy is not just a dream—it can be applied in real-world scenarios. Their solutions convert renewable electricity into usable power, produce green Hydrogen, and even make concrete that traps carbon. These technologies make low-carbon solutions practical, affordable, and ready for everyday use. They help industries and communities adopt cleaner production and more innovative energy use.
Looking ahead to 2025, climate change and a growing population are putting more pressure on our planet. These startups are more critical than ever. Their technologies reduce emissions and provide reliable energy solutions that go beyond small pilot projects. We can also expect further progress in energy storage, hydrogen production, and CO2 capture, helping build a cleaner economy for everyone. For more examples, see the best cleantech companies driving these changes.
Some leading U.S. cleantech startups include Fervo Energy, e-Zinc, CarbonBuilt, and Electric Hydrogen. These companies focus on practical, scalable solutions that reduce emissions and improve energy efficiency across industries.
Top European cleantech startups include HiiROC, Hydrogenious Technologies, Krajete, and Hystar. They focus on scalable, practical technologies to make renewable energy and green Hydrogen more accessible and reliable.
Cleantech startups reduce greenhouse gas emissions by developing renewable energy, green Hydrogen, energy storage, and carbon capture technologies. They make clean energy more efficient, affordable, and widely deployable, helping industries and communities transition from fossil fuels to low-carbon solutions.
Startups like CarbonBuilt, Climeworks, and others focus on capturing and permanently storing CO2. They create products or processes that lock carbon in solid materials, underground reservoirs, or industrial applications, helping lower atmospheric CO2 levels while maintaining economic feasibility.
