Cleantech Maturity Levels: Mapping the Path to a Sustainable Future
Cleantech technologies are evolving at differing speeds. While renewable sources like solar and wind have achieved commercial maturity, others, like carbon capture and green hydrogen, remain in earlier stages of development. Advancing the maturity of these emerging solutions is critical to the progress of future sustainability and requires strategic investment to accelerate the decarbonisation of vital industries.
Cleantech refers to multiple products, services, and processes intended to reduce environmental impact across various industries. According to Cleantech for Europe, cleantech applications span agriculture and food (e.g., regenerative farming, bio-based fertilisers), energy (renewables, storage, smart grids), materials and chemicals (like alternative fuels), transportation and logistics (electric vehicles, low-emission ships and planes), resource and environmental management (carbon capture, circular economy), and enabling technologies such as AI and quantum computing.
Mature Technologies: Solar, Wind, and Energy Storage
Technologies like solar and wind power are now well-established pillars of the energy transition. Sophia Karagianni, Senior Policy Officer at Cleantech for Europe, believes that solar and wind are some of the most advanced cleantech technologies and have already played a considerable role in reducing emissions in the energy industry. Karagianni also highlights energy storage, particularly lithium-ion batteries, as a vital resource for balancing variable energy supplies. “Energy storage, especially lithium-ion batteries, is also crucial for balancing variable energy supply.”
According to the IEA, solar energy is growing faster than any other power source. By the end of 2023, global installed photovoltaic capacity reached 1.6 terawatts—an increase of nearly 450 gigawatts in just one year. Renewables now provide more than 30% of global electricity.
For energy storage, traditional pumped hydro remains the dominant method, but utility-scale battery deployment is accelerating. Over 28 GW of battery capacity is already installed, with forecasts projecting up to 1,000 GW by 2030.
Other cleantech solutions in the mature category include offshore wind, electric vehicles (with around 40 million in use globally), and geothermal energy, which uses the Earth's internal heat for power generation.
Mid-Stage Technologies: Tidal Energy, SMRs, Green Hydrogen
This category includes technologies that are beyond the prototype phase but not yet widely deployed. Some are being piloted at small scales, while others are entering early commercial use.
● Tidal and Wave Energy: Though relatively underdeveloped, these marine technologies harness ocean movement to generate power. The Rance tidal power station in France, operational since 1966, still produces around 600 million kilowatt-hours per year.
● Advanced Nuclear Reactors: Small Modular Reactors (SMRs) offer a more flexible and potentially safer alternative to traditional nuclear power plants. Currently, 80 SMR projects are underway globally.
● Green Hydrogen: While hydrogen is widely used in industry, over 99% is still derived from fossil fuels. Alternatives include blue hydrogen (natural gas with carbon capture), pink hydrogen (nuclear-powered electrolysis), and green hydrogen (produced using renewable energy). New low-emission hydrogen facilities are being developed across China, the EU, India, and the U.S. The IEA anticipates global hydrogen production to increase to 38 million tonnes by 2030 - enough to meet nearly half of the global demand.
Early-Stage Technologies: Carbon Capture, Green Steel, Solid-State Batteries
These technologies are in early development or pilot phases, and widespread deployment depends on advances in other cleantech areas like hydrogen and energy storage.
● Green Steel and Alternative Fuels: Producing green steel or sustainable aviation fuels requires low-emission hydrogen, making them heavily dependent on scaling green hydrogen production.
● Carbon Capture and Storage (CCS): Although CCS has drawn significant interest, current deployment is limited. Around 45 operational facilities worldwide use CCS to capture emissions at their source, typically reusing the carbon in nearby processes. Direct air capture—removing CO₂ directly from the atmosphere—is still largely experimental, with pilot projects underway in the U.S., EU, UK, Canada, and Japan.
● Next-Gen Batteries: Solid-state batteries could deliver greater energy density, improved safety, lower costs, and reduced reliance on lithium. While mainly aimed at electric vehicles, other technologies such as molten salt batteries are being developed for grid-scale energy storage. These systems must operate at high temperatures, posing technical and cost challenges.
The Road Ahead: Investing in Transformation
“The most impactful technologies will be those that can transform the economy while tackling climate change and resource scarcity,” says Natalia Ruiz. “This includes solutions for sustainable mobility, efficient renewable energy, industrial decarbonisation, and circular economy initiatives.”
Meeting the climate goals set in the Paris Agreement will require the world to secure a path to net-zero emissions by 2030, and cleantech will be crucial to this transformation. Bianca Dragomir highlights that we must reduce emissions 12 times faster than the current figures. Clean technologies aren’t just the backbone of climate action, they're essential to global competitiveness and future prosperity.
