With a power generation capacity of over 1,250MW, the newly inaugurated plant is claimed to be the largest greenfield thermal power plant project in Russia since 1990, and will have an estimated annual production of 9.8TWh..

The plant’s first combine-cycle unit entered commercial operation in March 2013 and has been certified to exceed 420MW, while the second and third units are scheduled to be completed and commissioned in 2013 and 2014 respectively.

Fortum vice president and Russia Division head Alexander Chuvaev said Nyagan GRES will add the most efficient power generation facility to the gas- and oil-rich region of Russia.

"With Nyagan 1 in production since March, we are reaching the halfway mark of our investment programme that will nearly double our electrical capacity in Russia when finished next year,” Chuvaev added.

Fortum CFO Markus Rauramo said, "The Nyagan power plant represents the most significant part of Fortum’s investment programme in Russia, making the site an important landmark for our company.”

The company is currently running a €2.5bn investment program in Russia, which comprises eight gas-fired units, four of which have already been commissioned.

Construction of all units is anticipated to be finalized by the end of 2014.