Energy breakthrough: How long-duration storage could solve the renewable puzzle
Not just more solar or wind
long-duration energy storage is the real game-changer in clean energy: Turns out it isn’t just more solar or wind — it’s storage that lasts beyond sunset, storms, and grid shocks.
This solution offers a number of benefits: it raises reliability of energy and system flexiblity, while reducing overall cost.
In other words, it’s not just simple energy storage: It ramps up overall value.
What is long-duration energy storage (LDES)?
LDES refers to technologies that can store energy for extended periods, typically 8 hours or more, and release it when needed.
These solutions are vital for balancing intermittent renewable sources like solar and wind, ensuring grid stability during low production periods.
For instance, pumped hydro stores energy by pumping water uphill and generating power as it flows down.
Why is LDES important for the energy transition?
As countries shift to low-carbon power systems, renewables are expected to dominate electricity generation.
However, solar and wind are variable, creating mismatches between supply and demand.
LDES addresses this by storing excess energy for days or weeks, improving reliability, reducing costs, and cutting emissions.
IRENA reports show LDES could enable up to 90% renewable integration in grids, delivering system-wide savings.
Why LDES is gaining greater attention
Among policy makers, LDES is gaining greater attention.
For example, the EU’s Electricity Market Design requires member states to evaluate flexibility needs, prioritising non-fossil solutions like LDES.
The European electricity market is the largest integrated electricity market in the world, using 11.3 million km of power lines and cables across the EU alone — enough to encircle the Earth 282 times — to bring electricity to 266 million customers.
An integrated EU energy market is the most cost-effective way to ensure secure, sustainable and affordable energy supplies to EU citizens.
Common energy market rules and cross-border infrastructure allows energy to be produced in one EU country and delivered in another.
The EU internal energy market saves consumers €34 billion annually and, with deeper integration, this could rise to €40-43 billion by 2030.
The European Commission seeks deeper electricity market integration in the continent, ‘White Paper’ onis due for publication in early 2026.
The session highlights real-world deployments, such as Ireland’s 2.8 GW LDES need for an 80% renewable grid by 2030.