In the sun-drenched valleys of Spain, among the snowcapped peaks of the French Alps, and along the rushing rivers of Portugal, dozens of hydropower plants sit quietly during the day. Their turbines rest while the wind blows and the sun shines — and a new report says that energy is going to waste. But not for long.
A study from Ember, an independent energy think tank, reveals that Europe could add 25 gigawatts of clean wind and solar power simply by attaching it to existing hydropower sites across seven EU countries. That is enough clean electricity to power roughly 18 million European homes, without building a single new power line.
The technique is called hybridisation. It means combining wind, solar, and storage at the same grid connection point as a hydropower plant. Hydropower plants are especially good candidates because their grid capacity often sits idle during daylight hours, when the sun is strongest and wind patterns tend to favor turbines.
"By adding wind or solar at the same connection point as a hydropower plant, developers can get online faster and operators can use grid infrastructure more efficiently — on average doubling utilisation," said Elisabeth Cremona, Energy Infrastructures Lead at Ember.
The seven countries with the most potential are Austria, Bulgaria, France, Italy, Portugal, Romania, and Spain. Together, they are the EU's major hydropower markets. Ember researchers found that hybridisation could help integrate 18 percent of the new renewables Europe expects to add by 2030 without needing any new grid capacity at all. That is a significant shortcut at a time when countries are racing to cut reliance on imported fossil fuels.
But there is a catch. Of the seven countries studied, only Portugal and Spain have specific rules for hybrid energy projects. The other five lack clear regulatory frameworks, which slows down developers and creates uncertainty. Cremona argues that national governments need to pass new laws and treat hybrid projects as priorities.
"Grid scarcity calls for immediate solutions," she said. "National legislation, paired with faster, priority processing of hybrid projects, can remove barriers to renewable deployment and make better use of existing infrastructure."
The finding matters because grid congestion — too much clean energy trying to flow through too few wires — is one of the biggest bottlenecks slowing Europe's clean energy shift. Building new transmission lines takes years and faces local opposition. Hybridisation sidesteps that problem entirely by making smarter use of what already exists.
For everyday Europeans, this could mean lower electricity bills, cleaner air, and a more stable power grid — all without the years of construction that new infrastructure usually requires. The path forward depends on policymakers acting quickly to clear the regulatory roadblocks standing in the way.