Feeding output from wind and solar projects in the European Union to the grid through underused connections at hydroelectric power plants is a cost-effective way to deliver power and avoid worsening bottlenecks on power networks, energy analysts Ember said in a report on Tuesday.
Ember said that the capacity of grid connections at hydropower plants is typically underused, making it possible to use them to deliver wind and solar power at no extra cost, a technique referred to as hybridization of hydropower.
The report looked at seven EU member states that have 93 gigawatts of the EU's total 131 GW of hydropower capacity. The countries were Austria, Bulgaria, Portugal, Romania, France, Italy and Spain.
The seven countries studied will add an estimated 138 GW of wind and solar from now to 2030, according to grid operators, representing a 50% increase in capacity of these energy forms.
Ember's analysis found that about 25 GW of this, roughly 18% of the total, can be delivered to the grid via existing hydropower plant grid connections with no disruption to hydropower dispatch.
That would offer major efficiencies in terms of cost and construction time. The figure varies by country, with 77% of planned renewables additions able to enter the grid via hydropower facilities in Austria, but only 7% in Bulgaria.
"Hydropower assets in Europe are especially suited to hybridization because they typically leave substantial grid capacity unused for much of the day," Ember said.
Analysts noted that by integrating wind and solar behind the same grid connection point, "operators can maximize utilization of existing grid infrastructure while staying within injection limits."