Cambridge Energy News

The researchers, from the University of Cambridge, say their solar-powered reactor could be used to make fuel to power cars and planes, or the many chemicals and pharmaceuticals products we rely on. It could also be used to generate fuel in remote or off-grid locations.

Unlike most carbon capture technologies, the reactor developed by the Cambridge researchers does not require fossil-fuel-based power, or the transport and storage of carbon dioxide, but instead converts atmospheric CO2 into something useful using sunlight. The results are reported in the journal Nature Energy.

Carbon Capture and Storage (CCS) has been touted as a possible solution to the climate crisis, and has recently received £22bn in funding from the UK government. However, CCS is energy-intensive and there are concerns about the long-term safety of storing pressurised CO2 deep underground, although safety studies are currently being carried out.

“Aside from the expense and the energy intensity, CCS provides an excuse to carry on burning fossil fuels, which is what caused the climate crisis in the first place,” said Professor Erwin Reisner, who led the research. “CCS is also a non-circular process, since the pressurised CO2 is, at best, stored underground indefinitely, where it’s of no use to anyone.”

“What if instead of pumping the carbon dioxide underground, we made something useful from it?” said first author Dr Sayan Kar from Cambridge’s Yusuf Hamied Department of Chemistry. “CO2 is a harmful greenhouse gas, but it can also be turned into useful chemicals without contributing to global warming.”

The focus of Reisner’s research group is the development of devices that convert waste, water and air into practical fuels and chemicals. These devices take their inspiration from photosynthesis: the process by which plants convert sunlight into food. The devices don’t use any outside power: no cables, no batteries – all they need is the power of the sun.

The team’s newest system takes CO2 directly from the air and converts it into syngas: a key intermediate in the production of many chemicals and pharmaceuticals. The researchers say their approach, which does not require any transportation or storage, is much easier to scale up than earlier solar-powered devices.

The device, a solar-powered flow reactor, uses specialised filters to grab CO2 from the air at night, like how a sponge soaks up water. When the sun comes out, the sunlight heats up the captured CO2, absorbing infrared radiation and a semiconductor powder absorbs the ultraviolet radiation to start a chemical reaction that converts the captured CO2 into solar syngas. A mirror on the reactor concentrates the sunlight, making the process more efficient.

The researchers are currently working on converting the solar syngas into liquid fuels, which could be used to power cars, planes and more – without adding more CO2 to the atmosphere.

“If we made these devices at scale, they could solve two problems at once: removing CO2 from the atmosphere and creating a clean alternative to fossil fuels,” said Kar. “CO2 is seen as a harmful waste product, but it is also an opportunity.”

The researchers say that a particularly promising opportunity is in the chemical and pharmaceutical sector, where syngas can be converted into many of the products we rely on every day, without contributing to climate change. They are building a larger scale version of the reactor and hope to begin tests in the spring.

If scaled up, the researchers say their reactor could be used in a decentralised way, so that individuals could theoretically generate their own fuel, which would be useful in remote or off-grid locations.

“Instead of continuing to dig up and burn fossil fuels to produce the products we have come to rely on, we can get all the CO2 we need directly from the air and reuse it,” said Reisner. “We can build a circular, sustainable economy – if we have the political will to do it.”

The technology is being commercialised with the support of Cambridge Enterprise, the University’s commercialisation arm. The research was supported in part by UK Research and Innovation (UKRI), the European Research Council, the Royal Academy of Engineering, and the Cambridge Trust. Erwin Reisner is a Fellow of St John’s College, Cambridge.

Reference:
Sayan Kar et al. ‘Direct air capture of CO2 for solar fuels production in flow.’ Nature Energy (2025). DOI: 10.1038/s41560-025-01714-y

For more information on energy-related research in Cambridge, please visit the Energy IRC, which brings together Cambridge’s research knowledge and expertise, in collaboration with global partners, to create solutions for a sustainable and resilient energy landscape for generations to come. 

Researchers have developed a reactor that pulls carbon dioxide directly from the air and converts it into sustainable fuel, using sunlight as the power source.

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Hitting the current national 2030 quotas for solar and wind energy could reduce the volatility of electricity markets by an average of 20% across 29 European countries, according to a new study from the University of Cambridge.  

The intensity of spikes in power prices are predicted to fall in every country by the end of the decade if commitments to green energy are met, as natural gas dependency is cut.   

The UK and Ireland would be the biggest beneficiaries, with 44% and 43% reductions in the severity of electricity price spikes by 2030, compared with last year.

Germany could experience a 31% decline in electricity price volatility, with the Netherlands and Belgium seeing price spikes ease by 38% and 33% respectively.

The simulations conducted for the new study show that scaling up renewable energy minimises the market impact of fluctuations in natural gas price – increasing stability even when considering the reliance of renewable technologies on weather.

Some EU leaders and energy ministers have called for renewables targets on grounds of energy security as well as decarbonisation, particularly since Putin’s war on Ukraine stemmed the flow of Russian gas.

The study, published in the journal Nature Energy, calculates in detail how such aims would affect the volatility of wholesale electricity prices in energy markets across Europe.

“The volatility of energy prices is a major cause of damage to national economies,” said Laura Diaz Anadon, the University of Cambridge’s Professor of Climate Change Policy.

“Consumers are still reeling from sharp increases in electricity prices brought about by natural gas shortages following Russia’s invasion of Ukraine,” said Anadon. “We show that hitting renewables targets reduce the likelihood of such price spikes in the future.”

Daniel Navia, a researcher with the University’s Centre for Environment, Energy and Natural Resource Governance (CEENRG), said: “Meeting renewable energy targets is not only good for carbon neutrality, but we can see it is a boost to economic resilience”

“We had probably underestimated how costly energy price shocks are to our societies, and the last crisis has been a stark reminder.”

The Cambridge researchers used the University’s high performance computing facilities to model a wide range of factors – from fluctuations in weather patterns and energy demands to fuel capacity – to map the current and future grids of all 27 EU nations plus the UK and Switzerland.

They assessed electricity markets in 2030 based on the commitments to renewables as stated in each nation’s national energy and climate plan.

“The UK in particular is projected to see major benefits to its energy market stability from renewables,” said Anadon.

“The UK has struggled with its exposure to gas prices due to a lack of energy storage and limited connections to the European grid. This has led to more hours where electricity prices are set by natural gas.”

The research also suggests that wholesale prices of electricity could fall by over a quarter on average across all countries in the study by decade’s end if they stick to current national renewables targets.

Again, populations in the UK and Ireland stand to gain significantly, with electricity prices predicted to fall by around 45% by 2030, compared with the current situation.

Several of the Nordic nations could see over 60% reductions in electricity costs by 2030, while in Germany the price is predicted to fall by 34%, with Belgium seeing a similar drop of 31%. The study suggests the Netherlands could see the price of electricity fall by 41%.

While the study’s authors caution that trends in electricity prices depend on factors that are “impossible to predict”, they say their results are in line with recent outputs by institutions such as the International Energy Agency.

In fact, Navia and Anadon say their modelling may even underestimate the potential for electricity price stability across Europe, as the projections were calculated using data from 1990-2021 – before the energy crisis created by Russia’s attack on Ukraine.

“It makes sense to think about renewables as a security investment, and if we lose the momentum towards green energy, we are clearly harming the climate, but we also exposing ourselves to unknowable risks down the line,” said Anadon.  

The new study also charts the effects on electricity prices if countries overshoot on renewables. If Europe exceeds its renewable energy goals by 30%, electricity prices could become 50% less sensitive to natural gas, compared to just meeting renewables targets.

However, the study suggests there are tipping points where renewables cause the price of power to fall so far that it stops providing sufficient return on investment, and the green energy industries may stall. 

Added Navia: “If we are to fully utilise solar and wind as a security tool, Europe might have to rethink how its energy markets are designed, and what incentives it can offer the private sector to maintain the societal insurance value it gets from renewable energy.”

National targets for solar and wind power will see reliance on natural gas plummet, reducing electricity price volatility across Europe, with major beneficiaries including the UK and Ireland, the Nordics, and the Netherlands.

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The researchers, from the University of Cambridge and the University of California, Berkeley, developed a practical way to make hydrocarbons – molecules made of carbon and hydrogen – powered solely by the sun.

The device they developed combines a light absorbing ‘leaf’ made from a high-efficiency solar cell material called perovskite, with a copper nanoflower catalyst, to convert carbon dioxide into useful molecules. Unlike most metal catalysts, which can only convert CO₂ into single-carbon molecules, the copper flowers enable the formation of more complex hydrocarbons with two carbon atoms, such as ethane and ethylene — key building blocks for liquid fuels, chemicals and plastics.

Almost all hydrocarbons currently stem from fossil fuels, but the method developed by the Cambridge-Berkeley team results in clean chemicals and fuels made from CO2, water and glycerol – a common organic compound – without any additional carbon emissions. The results are reported in the journal Nature Catalysis.

The study builds on the team’s earlier work on artificial leaves, which take their inspiration from photosynthesis: the process by which plants convert sunlight into food. “We wanted to go beyond basic carbon dioxide reduction and produce more complex hydrocarbons, but that requires significantly more energy,” said Dr Virgil Andrei from Cambridge’s Yusuf Hamied Department of Chemistry, the study’s lead author.

Andrei, a Research Fellow of St John’s College, Cambridge, carried out the work as part of the Winton Cambridge-Kavli ENSI Exchange programme in the lab of Professor Peidong Yang at University of California, Berkeley.

By coupling a perovskite light absorber with the copper nanoflower catalyst, the team was able to produce more complex hydrocarbons. To further improve efficiency and overcome the energy limits of splitting water, the team added silicon nanowire electrodes that can oxidise glycerol instead. This new platform produces hydrocarbons much more effectively — 200 times better than earlier systems for splitting water and carbon dioxide.

The reaction not only boosts CO₂ reduction performance, but also produces high-value chemicals such as glycerate, lactate, and formate, which have applications in pharmaceuticals, cosmetics, and chemical synthesis.

“Glycerol is typically considered waste, but here it plays a crucial role in improving the reaction rate,” said Andrei. “This demonstrates we can apply our platform to a wide range of chemical processes beyond just waste conversion. By carefully designing the catalyst’s surface area, we can influence what products we generate, making the process more selective.”

While current CO₂-to-hydrocarbon selectivity remains around 10%, the researchers are optimistic about improving catalyst design to increase efficiency. The team envisions applying their platform to even more complex organic reactions, opening doors for innovation in sustainable chemical production. With continued improvements, this research could accelerate the transition to a circular, carbon-neutral economy.

“This project is an excellent example of how global research partnerships can lead to impactful scientific advancements,” said Andrei. “By combining expertise from Cambridge and Berkeley, we’ve developed a system that may reshape the way we produce fuels and valuable chemicals sustainably.”

The research was supported in part by the Winton Programme for the Physics of Sustainability, St John’s College, the US Department of Energy, the European Research Council, and UK Research and Innovation (UKRI).

Reference:
Virgil Andrei et al. ‘Perovskite-driven solar C2 hydrocarbon synthesis from CO2.’ Nature Catalysis (2025). DOI: 10.1038/s41929-025-01292-y

Tiny copper ‘nano-flowers’ have been attached to an artificial leaf to produce clean fuels and chemicals that are the backbone of modern energy and manufacturing.

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