Serbian oil company NIS has started building a 200 megawatt (MW) gas-fired cogeneration plant, the biggest in the Balkan country so far, that will supply its Pancevo oil refinery and Serbia’s energy market.

The plant is a joint venture between NIS, majority owned by Russia’s Gazprom Neft, and Gazprom Energoholding, a subsidiary of Russian gas giant Gazprom. The two firms hold 49 and 51 percent stakes respectively, according to Reuters.

The plant will be built by China’s Shanghai Electric Group at an estimated cost of 180 million euros ($203.56 million), with a target completion date in the last quarter of 2020.

It will burn natural gas to produce power, which will also be used for district heating energy for the town of Pancevo.

One of the biggest contributors to Serbia’s budget, NIS operates two refineries, plus fields in Serbia, Bosnia, Hungary, Romania and Angola.