Clean Energy in 2025: Top Trends and Cleantech Startups

From blockchain to solar kits, the latest scoop on clean energy trends and the visionary startups behind them. 

In January 2025, global temperatures reached 1.75°C above pre-industrial levels, the 18th month out of 19 in which temperatures surpassed 1.5°C above pre-industrial levels. In a period of La Niña, a usually cooling effect on the global climate, these record breaking temperatures highlighted the immediacy for action and innovative solutions to global warming.

That's where cleantech comes in; a growing industry making sustainable living more accessible and affordable, creating greenjobs, and heading up the shift towards net-zero emissions, cleantech startups are leading the way with practical and smart ideas to combat climate change, using clean energy solutions.

What is Clean Energy?

As the name suggests, clean energy is any type of energy that is produced from non-polluting sources and that doesn't contribute substantially to climate change. Clean energies typically include renewable or sustainable sources that limit the amount of environmental impact. 

Unlike traditional sources of energy, such as coal, oil and natural gas, clean energy sources impact global warming at a significantly lower scale than fossil fuels, either with zero or low carbon emissions. 

Overall, clean energy sources usually include the following characteristics:

• Sustainable or Renewable 
• Zero or Low Carbon Emissions
• Minimal Environmental Impact 

Aside from its reduced negative impact on the environment and climate change, clean energy is a vital part of improving public health, creating industries and generating jobs. 

Traditional energy sources, such as coal and gas, release harmful and toxic pollutants into the atmosphere. As such, the increased prevalence of particulate matter, nitrogen oxides and sulfur dioxides has been linked to asthma, bronchitis and heart disease. By implementing clean energy sources, it is possible to improve air quality, reduce the risk and incidence of air pollution-related deaths and lower healthcare costs.

In addition to improved air quality, cleaner water also promotes safer communities. Fossil fuel extraction for coal and natural gas results in polluted water supplies, with higher levels of heavy metals and toxic chemicals.

Some common examples of clean energy sources include:

• Solar Energy - Harnessing the sun’s light energy to generate electricity, through the use of panels.
• Hydropower - Using the powerful flow or fall of water to generate electricity.
• Wind energy - Exploiting the natural phenomenon of wind to power turbines for electricity generation. 
• Geothermal - Tapping into the natural internal heat of the Earth to produce power.
• Biomass - Converting organic waste, such as food, into energy.

What is Cleantech?

Before we dive into the latest trends and forecasts for clean energy startups, let's first pin down the basics. So, what is cleantech really? And why is cleantech garnering attention these days? 

Simply put, cleantech, an abbreviation of clean technology, refers to the innovative technologies that reduce negative environmental impacts and promote the sustainable use of resources. In general, clean tech is the technological part of sustainability; it capitalizes on smart solutions to solve environmental issues, without foregoing economic growth or performance. 

Now, you might be thinking, sowhat’s the difference between cleantech and greentech? 

Over the past few years, greentech has become a buzzword for the startup world but there’s a new kid on the block: cleantech. While greentech is a broader term generally used for personal or environmental choices, cleantech focuses on practical, scalable and innovative solutions that can be implemented commercially and broadly. 

Some concrete examples of cleantech include the following:

• Carbon Capture Storage (CCS)
• Electric Vehicles & Hydrogen Fuel Cells 
• Recycling Robotics
• Solar Panels & Wind Turbines 
• Vertical Farms & Precision Farming

In the drive towards net zero carbon emissions and sustainable living, cleantech is a must. So, with the basics under our belt, let's dive into the latest cleantech investments and trends!

Top Ten Trends for Cleantech in 2025

With a focus on creating scalable solutions that address the current environmental challenges, the following cleantech trends are leading the way in 2025:

• Advanced Renewable Energy Integration: As global demand for clean power continues to rise, technologies are evolving to seamlessly weave together solar, wind, and hydro into existing power grids. These Innovations focus on improving grid stability, load balancing, and storage capacity.
• Next-Gen Energy Storage: New breakthroughs in solid-state batteries, flow batteries, and other storage systems are solving the problem of renewable intermittency. This ensures a consistent energy supply, even when the sun isn’t shining or the wind isn’t blowing.
• Carbon Capture, Utilization & Storage (CCUS): Instead of allowing carbon to escape into the atmosphere, CCUS tech is capturing it at the source and repurposing it for use in concrete, fuels, or industrial processes, turning a once pollutant into a resource.
• Green Hydrogen Production: Hydrogen produced from renewable sources, like electrolysis powered by wind or solar, is gaining momentum as a clean fuel for heavy industry, aviation, and long-haul transport.
• Circular Economy & Sustainable Materials: Cleantech is embracing the "waste nothing" mindset by promoting the design of products with recyclable, biodegradable, or reusable components, in an attempt to reduce environmental footprints across the supply chain.
• Smart Energy Systems: From AI-powered grid management to energy analytics for buildings and factories, intelligent software is optimizing when, where, and how we use energy, helping cut costs and emissions.
• Eco-Friendly Mobility Solutions: The rise of electric vehicles, e-bikes, green public transit, and hydrogen-fueled transport is making sustainable travel more accessible, efficient, and emission-free.
• Water Tech & Clean Infrastructure: Innovative water solutions, like atmospheric water generators, advanced filtration, and wastewater-to-energy systems, are ensuring access to clean water in an increasingly warmer world. 
• Decentralized Renewable Energy: Cleantech is moving away from centralized grids. Rooftop solar, microgrids, and community-based power systems are empowering homes, communities, and neighborhoods to generate and control their own energy supply. 
• Clean AI and Green Data Centers: The tech that powers our digital lives consumes huge amounts of water and energy. In 2025, a growth in energy-efficient data centers, AI models optimized for low-power operation, and software tools to track digital carbon footprints is unfolding.

Financing cleantech startups are a particular set of visionary investors; simultaneously conscious of the earth’s climate situation and seeking scalable solutions that can generate economic growth, cleantech investors are somewhat of a niche.. 

At Angel’s Partners, you can filter searches to explicitly look for investors actively prospecting cleantech startups. With a database of over 120,000 investors, it's never been easier to search, contact and connect with cleantech investors!

Top Ten Cleantech Startups in 2025

Leading the way in this game-changing sector are startups using AI, nuclear reactors and even blockchain to produce original solutions to the climate crisis. We’ve pulled together ten standout cleantech startups offering innovative solutions to advance clean and sustainable energy:

• Preflet (Germany) – Intelligent Energy Management for Buildings

Preflet has developed a platform that provides commercial building owners with detailed analytics on energy consumption, costs, and carbon emissions. By integrating with smart meters and building systems, Preflet can identify inefficiencies and suggest actionable improvements, facilitating immediate energy savings and supporting decarbonization efforts.

• Found Energy (USA) – Transportable Renewable Energy via Aluminum Fuel Packs

Found Energy utilizes aluminum scrap to create modular fuel packs that generate hydrogen and steam through a corrosion process. Each pack can produce significant energy on demand, offering a cost-effective and environmentally friendly alternative to traditional fossil fuels, especially in areas lacking renewable infrastructure.

• Elyos Energy (UK) – AI-Driven Energy Optimization

Elyos Energy offers a platform that leverages machine learning to optimize energy consumption and manage demand response. By analyzing real-time data, it enables businesses to reduce energy usage during peak periods, lower electricity costs, and participate in grid flexibility programs.

• FusionOne (Canada) – Converting Plastic Waste into Green Hydrogen

FusionOne has developed the HydroPlas reactor, which thermally decomposes plastic waste in an oxygen-free environment to produce hydrogen-rich syngas. This syngas is then purified into green hydrogen, providing a dual solution for waste management and clean energy production.

• MoltexFLEX (UK) – Modular Nuclear Reactors for Consistent Energy Supply

MoltexFLEX designs compact nuclear reactors that produce high-temperature thermal energy, which is stored in thermal tanks for on-demand electricity generation. These reactors are passively safe, require infrequent refueling, and complement renewable sources by providing consistent power when needed.

• Tornasol Energy (Spain) – User-Friendly Solar Energy Kits

Tornasol Energy offers plug-and-play solar kits that are lightweight and easy to install on various surfaces, such as balconies and rooftops. These modular kits allow users to generate renewable energy without complex installations, promoting wider adoption of solar power.

• GKN Hydrogen (Italy) – Safe and Sustainable Hydrogen Storage

GKN Hydrogen provides metal hydride-based storage systems that safely store green hydrogen at low pressures. These systems are recyclable, produce no operational waste, and are suitable for various applications, including backup power and off-grid energy supply, supporting a decentralized energy infrastructure.

• Gideon One (Thailand) – Blockchain-Based Energy Trading Platform

Gideon One has developed a platform that facilitates transparent and secure electricity trading using blockchain technology. By collecting data directly from meters, it enables real-time tracking of energy production and consumption, enhancing market efficiency and reducing energy waste.

• WatGen (Chile) – Mobile Renewable Power Solutions

WatGen is a solar-powered mobile energy unit that delivers high-efficiency power suitable for industrial applications. With substantial energy storage capacity, it serves as a clean alternative to diesel generators, particularly in construction and remote operations.

• Saiflow (Israel) – Cybersecurity for Energy Infrastructure

Saiflow offers a cybersecurity platform designed to protect electric vehicle charging stations and energy networks from cyber threats. It provides real-time monitoring, malware detection, and network segmentation, ensuring the security and reliability of modern energy systems.

Whether it’s harnessing the power of natural energy sources, or incorporating AI and machine learning into smart systems, cleantech is revolutionising the way we produce, use and dispose of energy.