Estonian company WiSo Engineering to build largest hybrid plant in Estonia

One of the largest solar parks in the Baltics at Kirikmäe will soon be supplemented with a 55 MW battery storage system with a storage capacity of 250 MWh, to be constructed and placed on the electricity market by the Estonian company WiSo Engineering. As a result of the construction work, the highest-capacity hybrid plant in Estonia with a capacity of 77.5 MW will become operational at Kirikmäe thanks to the combined effect of the solar park and the battery storage system.

The new battery park will be constructed in the proximity of the existing Kirikmäe solar park built by WiSo Engineering and integrated as a whole with the production unit. This hybrid solution allows for storing the electricity produced in the solar park and to supply it to the market as needed by the electricity system and electricity market.

Risto Virveste, CEO of WiSo Engineering, noted that the hybrid capacity of existing solar parks holds substantial potential for growth in the energy sector. The energy infrastructure construction company that has formerly focused on the construction of solar parks therefore considers battery storage parks as its new focus in addition to solar parks in the changing market conditions.

“WiSo Engineering alone has built dozens of large-scale solar parks in the region in the last few years. In order for solar parks to efficiently participate on the market, ensuring the hybrid operation of these parks is becoming ever more important in order to ensure the flexibility and stability that the energy system needs,” said Virveste.

Nearly 700 MWh of battery storage capacity in the portfolio

Hertz 1, the largest battery storage plant in Estonia, with a total output capacity of 100 MW and a total storage capacity of 200 MWh has already been completed, with WiSo Engineering involved in the project. However, the Hertz 1 battery storage plant at Kiisa merely constitutes the first stage. Hertz 2, a second battery storage park of the same size and capacity, will be completed already this spring with the contribution of WiSo Engineering. This means that the two parks in total will account for an integrated capacity of 200 MW and 400 MWh, thus becoming one of the largest battery storage park complexes in the entirety of Continental Europe.

Active preparation work is meanwhile being performed at Kirikmäe hybrid plant in order to commence construction activities. The work performed by WiSo Engineering includes design work, preparation and construction of the access roads and the construction site, as well as the installation of the battery containment equipment for the battery storage plant along with the accompanying equipment and the related electrical work. WiSo will then conduct the electricity network and market testing required for the connection of the battery storage park with the electricity network in order to appropriately integrate the system with the energy system and render it operational. In short, the sphere of responsibility of WiSo Engineering includes everything from the preparation of the construction site to placing the battery storage park on the market.

The plant will be completed already in the second half of the year, with operation immediately commencing on various energy markets. Upon completion, the hybrid system will allow for storing solar power and providing important services with regard to grid stability, e.g. arbitrage and various frequency markets. By the end of the year, the portfolio of WiSo Engineering in relation to battery storage construction activities will reach 700 MWh, which means WiSo will be one of the companies with the most extensive experience in battery storage solutions in Estonia.

The battery storage system of Kirikmäe hybrid plant is being developed by the international investment fund Mirova and the Estonian energy company Evecon via the joint venture Baltic Renewable Energy Platform (BREP).

According to Karl-Joonatan Kvell, CEO of Evecon, WiSo Engineering has proven itself as a reliable partner for the implementation of large-scale projects and is in possession of the required knowledge and experience. “Such competence and reliability is of vital importance when our aim is to create strategic storage solutions with respect to the Baltics and the European energy system,” said Kvell.