Existing hydropower plants in seven of the European Union’s largest hydro markets could accommodate up to 25 GW of additional wind and solar capacity without requiring new grid infrastructure, according to analysis by energy think tank Ember.
The report examines hydropower assets in Austria, Bulgaria, France, Italy, Portugal, Romania and Spain, which together account for 93 GW of the EU’s 131GW of installed hydropower capacity. It concludes that hybridising existing hydro plants by adding wind or solar generation behind the same grid connection could provide 18% of the renewable capacity these countries plan to install by 2030.
Ember argues that sharing existing grid connections offers a way to continue renewable deployment as grid constraints increasingly delay new projects across Europe. The report estimates a gap of more than 120 GW between available grid capacity and anticipated renewable growth by 2030, with connection shortages already affecting several countries.
The study found that many hydropower plants make limited use of their existing grid connections because they operate primarily during periods of peak electricity demand. Reservoir and pumped storage plants included in the analysis have an average capacity factor of 19%, leaving significant spare connection capacity that could be used by solar or wind generation. According to Ember, hybridisation could increase average grid connection utilisation to 36% with solar and 31% with wind without changing the dispatch behaviour of existing hydro plants.
The report excluded hydropower facilities located near protected areas from its assessment and found that around 28% of large hydropower capacity across the seven countries remained suitable for hybrid development after environmental screening. Austria and Italy had the highest eligible shares, while Bulgaria had the lowest.
Hybridisation potential varies considerably between countries. Austria could meet around 77% of its planned renewable additions through hydro hybridisation, while Bulgaria could meet around 7%, reflecting differences in both renewable deployment targets and site availability.
The report also highlights a lack of dedicated regulation for hybrid projects across most of Europe. Among the seven countries assessed, only Portugal and Spain have established specific regulatory frameworks to support hybrid renewable developments. Ember says wider adoption will require national legislation, streamlined permitting and faster grid connection procedures.
Elisabeth Cremona, energy infrastructures lead at Ember, said hybridisation offers “an immediate, zero-intervention solution” for countries facing grid bottlenecks by allowing wind and solar projects to share existing hydro grid connections rather than waiting for new network capacity.
