Researchers at the Paul Scherrer Institute (PSI) in Switzerland have developed a practical strategy to reduce carbon emissions from road transport while keeping costs manageable.
Their plan relies on clever energy storage methods and increased use of carbon dioxide (CO2) from biogas plants.
The study was recently published in the journal Energy Conversion and Management.
Transport accounts for a large share of Switzerland’s carbon emissions—41% in 2022.
While electric vehicles are becoming common for passenger cars, heavy trucks face unique challenges.
Trucks powered by hydrogen are more practical than battery-powered ones due to their longer range, lighter weight, and faster refueling.
However, both technologies need renewable electricity to truly cut emissions.
A big hurdle is the seasonal availability of renewable energy. Solar power, for example, is abundant in summer but scarce in winter.
This raises a critical question: How can we ensure enough renewable energy for transport year-round while keeping costs competitive?
The PSI team proposes a two-step process to store excess renewable electricity produced during sunny seasons and make it available in winter when it’s needed most.
- Storing Energy as Hydrogen, Methane, and Methanol
During summer, when renewable electricity production exceeds demand, the surplus energy is used to split water into hydrogen and oxygen through a process called electrolysis. The hydrogen is then converted into two energy-dense fuels: methane (a gas) and methanol (a liquid). These fuels are much easier to store and transport than hydrogen because they take up less space and don’t require expensive infrastructure. - Releasing Stored Energy in Winter
In winter, the stored methane and methanol are transported to fueling stations. Methanol is more efficient for producing hydrogen through a process called steam reforming, while methane is ideal for generating electricity. This energy is then used to power electric and hydrogen-fueled vehicles.
Biogas plants, which process organic waste to produce biogas, play a key role in this system. They already produce CO2 as a byproduct, which can be captured and used to produce methane and methanol.
This makes the process both cost-effective and sustainable.
By combining biogas processing with hydrogen production, additional infrastructure such as tanks and pipelines can be integrated at biogas plants. The methane can even be transported using existing natural gas pipelines, making the system efficient and scalable.
The PSI researchers examined costs using data from the Werdhölzi biogas plant in Zurich. They calculated the size and cost of facilities needed to implement their system. While producing electricity and hydrogen this way is currently more expensive than using petrol, the gap isn’t insurmountable.
With incentives like CO2 certificates or carbon pricing, this system could compete with fossil fuels. Moreover, the benefits of reducing greenhouse gas emissions were not included in the cost analysis. In some cases, capturing and storing CO2 could even result in negative carbon emissions, offering a major environmental advantage.
The PSI plan highlights the need for more renewable energy storage systems to balance seasonal supply and demand.
For example, the expansion of solar power is limited because sunny summer months already produce more energy than the grid can use. By storing this excess energy, the installation of more solar panels becomes practical, creating a foundation for cleaner transport systems.
The proposed approach offers a way to make low-carbon transport a reality. While challenges remain—such as increasing renewable electricity production and scaling up storage systems—the concept shows great promise.
Emanuele Moioli, a lead researcher on the project, sums it up: “Our strategy reduces the cost gap between clean and fossil fuels and creates opportunities for sustainable transport. With more renewable energy and better storage, we can move toward a future of climate-friendly mobility.”
This innovative energy plan not only addresses the challenges of decarbonizing transport but also offers a sustainable way to balance renewable energy production and demand throughout the year.
Source: KSR.
