Green energy for a sustainable future
At Enefit Green we contribute to the continuous development of the automated and digitalized production process. Our production portfolio includes a hybrid renewable energy production solution on Ruhnu Island and the Keila-Joa hydroelectric power plant.
We built a unique renewable energy solution on Ruhnu Island in 2018.
Previously, all the electricity needed on the island was generated with a diesel generator that emitted 500 tons of carbon dioxide per year. Enefit Green now produces at least 50% of the electricity consumed on the island from renewable energy sources, thus having halved its carbon dioxide emissions.
The annual electricity consumption of Ruhnu Island is approximately 600 megawatt-hours. The population is about 60 people, which multiplies during the summer holiday and tourist season. The area of the island is approximately 12 km2 and it is located 95 km away from Pärnu as the crow flies.
Solar panels
200 kW
Electric wind turbines
50 kW
Battery bank
180 kW and 220 kWh
Biodiesel generator
160 kW
Ruhnu Island is supplied with electricity by a unique solution consisting of solar panels (200 kilowatts), wind turbine (50 kilowatts), battery bank (180 kilowatts and 220 kilowatt-hours) and a biodiesel generator (160 kilowatts) driven by smart automation.
The solution includes a battery bank that allows storing energy generated from wind and sunlight for a time when the weather does not favour electricity production. In order to ensure electricity supply in all seasons and in all weathers, the island has a diesel generator that partly uses biodiesel.
The total capacity of the energy solution on Ruhnu is 590 kilowatts, which is enough to cover the electricity need of the entire island.
Although Estonia has no natural conditions for large-scale hydropower production, it is still quite reasonable to use the resources available.
Estonia has an estimated theoretical hydropower potential of up to 30 MW, of which 10 MW is realistically usable.
Enefit Green produces hydropower at its Keila-Joa Hydroelectric Power Plant.
The fully automated hydro plant is remotely operated. The site has an operations manager who ensures the operation of the plant based on regular inspections. The hydroelectric power plant located on a natural river plateau does not inhibit fish migration.
The plant has an asynchronous generator and a Kaplan turbine with adjustable operation and control blades with a nominal flow rate of 5.5 m3/s and an operating pressure of 8.7 m. The diameter of the turbine is one metre.
The manor mill in Keila-Joa has been recorded in historical documents since the 16th century. Electricity generation in Keila-Joa started in 1928.
The mill building under heritage protection was renovated in its original form in 2006 and new hydropower production equipment was installed.
During the renovation, all the facilities of the hydroelectric power plant were renovated, the mill building under heritage protection was restored and new hydropower production equipment was installed.
During the renovation work, the nominal capacity of the power plant was increased from 250 kilowatts to 365 kilowatts and its annual output to about 2.5 gigawatt-hours.