Engineers in Germany have found a way to overcome the fickle nature of wind power generation – they are building a hybrid wind-hydro power system: a wind turbine that will be storing water for hydroelectricity.

Reports on Quartz stated that the hybrid power system will store water inside wind turbines and allow the towers to act like massive batteries once the wind stops blowing.

It said it is the first major example of the two technologies being physically integrated to supply reliable renewable energy, and that the four-turbine project was announced by General Electric this month.

According to GE, the turbine will store energy from the spinning blades by pumping water about 100 feet up inside the turbine structure itself.

Also, basins around each base will store another 9 million gallons. When the wind stops, water flows downhill to generate hydroelectric power.

The report explained that German firm Max Bögl Wind AG had in March approached GE Renewable Energy to collaborate on the first wind farm with an integrated hydropower plant.

The four-turbine pilot project will be connected to the grid by the end of 2017, and the hydropower plant should be operational by the end of 2018.

The wind farm is located in Germany’s Swabian-Franconian forest and will feature the tallest turbines in the world at 809 feet (246.5 meters).

At full capacity, it should produce 13.6 megawatts, along with another 16 megawatts from the hydroelectric plant.

According to the report, Germany is in the midst of its ‘energiewende’ or energy transition, as it attempts to virtually eliminate fossil fuels.

Germany also said it aims to draw 45% of its energy from renewables by 2030 and reach 100% by 2050.

Agora Energiewende, a German clean energy think tank in 2015 reported that Germany’s average renewable mix was 33%.

However, GE said the wind farm is the first major project that integrates water storage in the turbines themselves.