A recent research shows that storing renewable energy as synthetic liquid fuels across multiple years can dramatically boost energy security, cut fossil imports, reduce costs, and reliably protect net-zero energy systems against unpredictable climate-driven shortages.
If the energy transition was a movie, weather would be the unpredictable villain—sometimes calm, sometimes chaotic, and always influential. As Europe and the world push toward net-zero systems powered by renewables, the big question arises:
How do we keep the lights on when the wind stops blowing, the sun hides for months, or a multi-year drought reduces hydropower?
Short-term fixes like batteries and demand shifting help for hours or days. But climate-driven energy droughts can last months or even years. That’s where this research steps in.
In the paper “The Liquid Buffer: Multi-Year Storage for Defossilization and Energy Security under Climate Uncertainty,” researchers from ETH Zurich and the University of Oslo propose a breakthrough strategy:
Use synthetic liquid hydrocarbons—made from renewable electricity—as a massive multi-year storage buffer for Europe.
It’s like creating an energy savings account that you can dip into during tough years.
Wind and solar power fluctuate not only daily or seasonally, but also year to year. For example:
These long-term mismatches can cause what researchers call energy droughts — prolonged periods where renewable generation is insufficient.
Europe already experienced a mini-version of this during the recent winters when low wind and high heating demand strained grids.
Most energy planning today assumes we only need to shift energy across hours or days. But the research argues that:
We must prepare for rare but extreme multi-year deficits caused by climate uncertainty.
However, direct modeling of 50,000+ potential climate years would be computationally impossible… until this paper introduces a smart, scalable method.
The authors create a stochastic (probabilistic) model that captures long-term climate uncertainty while staying computationally tractable.
Here’s the groundbreaking insight:
Instead of wasting renewable energy during surplus years…
Convert excess power → hydrogen → synthetic liquid hydrocarbons (like synthetic oil).
…and store these fuels for years
These multi-year liquid energy reserves become Europe’s strategic buffer against bad-weather years.
In the same way nations store crude oil in giant tanks and caverns, we can store renewably made liquid fuels—but now as a climate-friendly backup.
Why liquids? Because:
The authors call this giant reserve the Liquid Buffer.
That equals €13 billion saved per year across Europe.
In energy-systems research, shaving off even 1% is huge—so 4.1% is a big deal.
Why does it save money?
With multi-year storage:
This reduces exposure to geopolitical shocks and price volatility.
Today, much renewable energy gets wasted because it can’t be stored. With multi-year storage, this energy is saved, converted, and used in future years.
This sounds massive, but:
When considering combined oil and gas reserves, the EU currently holds four times that volume in its existing storage facilities.
So achieving this is realistic using existing approaches.
Additionally:
Unserved energy (power shortages) drops to 0.0035‰, well below the standard target of 0.02‰.
Meaning: Almost no blackouts — even in bad climate years.
Fuel imports are often unreliable during crises (as 2022 proved).
Multi-year storage provides “local insurance” against external shocks.
Here’s the intuitive flow:
Instead of curtailing:
The system:
Hydrogen gets all the attention—but for multi-year storage, liquids are better:
| Feature | Hydrogen | Synthetic Liquid Fuels |
|---|---|---|
| Energy density | Low | High |
| Storage cost | High (caverns needed) | Low |
| Infrastructure | Limited | Extensive & proven |
| Long-term storage | Challenging | Easy |
| Transport | Requires new pipelines | Ships, tanks, rails already exist |
This explains why the researchers see synthetic oil as the cornerstone of Europe’s climate-secure energy future.
To handle 51,840 climate years, the researchers developed:
This technique could become a new standard for energy security modeling.
Because surplus isn’t wasted anymore.
Electrolyzers run harder during good years.
Thermal plant operation drops by more than half.
Air-source heat pumps replace more expensive alternatives, thanks to improved winter electricity availability.
This research shows Europe can secure reliable supply without relying on uncertain fossil imports—even under extreme climate variability.
Expect growing investment in:
Synthetic fuel hubs may become the new backbone of the EU’s energy security.
In deficit years, the system allows temporary positive emissions.
In good years, DAC removes extra CO₂ to compensate.
This provides carbon flexibility and operational resilience.
Future studies may incorporate:
The modeling framework can adapt to these future insights.
To store and refine 525 TWh of synthetic oil, Europe will need:
Many of these already exist for fossil fuels — a major advantage.
Governments may:
This paper’s core message is powerful:
Climate uncertainty is not a barrier to renewable-based, net-zero energy systems.
Multi-year storage—especially through synthetic liquid fuels—can provide affordable, reliable energy security.
By converting surplus renewable energy into storable liquid fuels, Europe can:
The Liquid Buffer could become one of the key pillars of Europe’s long-term energy strategy — and a model for the world.
Energy Storage - A way to save energy now so we can use it later — like a battery for the whole energy system. - More about this concept in the article "Long Duration Energy Storage | Cracking the Code".
Renewable Energy - Energy from natural sources that constantly replenish, such as sun, wind, and water. - More about this concept in the article "Forecasting the Future of Renewable Energy: Smarter, Faster, Better!".
Wind Power - Electricity generated by turbines that capture the kinetic energy of moving air.
Solar Power (PV) - Electricity produced when sunlight hits photovoltaic panels and frees electrons.
Hydropower - Energy created from moving water, usually using dams or river flows.
Energy Drought - A long period (months or even years) when renewable energy generation is unusually low because of weather conditions. - More about this concept in the article "Energy Resources vs Droughts | Building Weather-Proof Power Systems".
Curtailment - When we waste renewable energy because the grid can’t use or store it fast enough.
Synthetic Liquid Fuels - Man-made fuels (like synthetic oil) produced using renewable electricity, hydrogen, and captured carbon.
Electrolysis - The process involves the application of electrical energy to separate water, yielding distinct streams of hydrogen and oxygen. - More about this concept in the article "Powering a Net-Zero Future: The Circular Economy of Solid Oxide Cells".
Hydrogen Storage - Saving hydrogen gas in special tanks or underground caverns so it can be used later for electricity or fuel.
Direct Air Capture (DAC) - Technology that pulls CO₂ directly from the air — like a giant air purifier for the planet. - More about this concept in the article "Powering Profit | Direct Air Capture in Volatile Markets".
Stochastic Modeling - A mathematical approach that handles uncertainty by analyzing many possible future scenarios.
Climate Uncertainty - The natural unpredictability in weather patterns from year to year, affecting renewable energy production.
Heat Pump - A device that moves heat from one place to another (like a fridge in reverse) to warm or cool buildings efficiently.
Thermal Generation - Electricity produced by burning fuels (like gas or oil) — typically used as backup when renewables dip.
Energy System Security - Ensuring a region always has enough energy, even during extreme weather or supply disruptions.
Leonard Göke, Jan Wohland, Stefano Moret, André Bardow. The Liquid Buffer: Multi-Year Storage for Defossilization and Energy Security under Climate Uncertainty. https://doi.org/10.48550/arXiv.2511.13513
From: ETH Zurich; University of Oslo.
