OREANDA-NEWS. June 27, 2012. Last week, with the launch of the steam turbine at Lietuvos energija’s new combined cycle gas turbine unit, full capacity was reached for the first time during testing. The 455 MW unit will be able to meet as much as one third of Lithuania’s total energy demand. It is planned that testing of the unit will continue until August, and full operation will begin this autumn. Once testing is completed, the construction contractors will hand over exploitation of the unit to the company’s team of specialists. The combined cycle unit has already generated 16 306 MWh of electricity.

“Since February, the unit has been being tested in different operating modes, and the aggregate performance of all of the systems has been being checked. Reaching full capacity is a crucial step in the testing. The gas and steam turbines, as well as all of the auxiliary systems, are now operating together successfully,” said Lietuvos energija CEO Dalius Misiunas.

The gas turbine had been tested previously. Upon testing the steam turbine, the combined cycle unit began operating full-cycle: heat from the gas turbine is directed into the boiler where steam is generated and then supplied to the steam turbine, which is mounted on the same shaft as the gas turbine. This is called the "single shaft" principle – when the same generator is driven by both gas and steam turbines. This process allows the unit to achieve an efficiency of 58%.

In an effort to ensure that the equipment operates without interferences and to identify potential factory defects or design/installation errors which are bound to occur in such projects, testing of the steam and gas turbines will continue. Failure of the current transformer which occurred during testing in March is an example. After extensive investigations, the manufacturer acknowledged that this was indeed a factory defect, and provided new equipment.

The purpose of the new combined cycle unit is to increase the Lithuanian Power Plant’s production capacity, reliability and efficiency, and reduce the cost of electricity generation. This unit, which will replace units 3 and 4 of the Lithuanian Power Plant, will require approximately 30% less gas to produce a kilowatt-hour. It is also environmentally superior – it will allow for the reduction of air pollution.

An agreement concerning the construction of the combined cycle unit was signed with Spanish concern Iberdrola Ingenieria y Construccion, S.A.U. in the end of April, 2009. General Electric was chosen as the main equipment supplier.