Gardabani Combined Cycle Thermal Power Plant, Kvemo Kartli, Georgia
The 230MW Gardabani combined-cycle thermal power plant in the Kvemo Kartli region of Georgia was developed by the Partnership Fund (PF), Georgia's state-owned shareholding company, and its subsidiary the Georgian Oil and Gas Corporation (GOGC).
The combined-cycle thermal power plant has the capacity to produce 1.8TWh of energy annually and is the first of its kind in the country. It has the reserve capacity to supply the country's energy grid for 25 to 30 minutes in the case of a power failure.
Construction of the plant began in January 2013 and was commissioned in October 2016. The estimated cost of the project is $220m.
Gardabani combined-cycle power plant ownership and financing
The Lichterfelde gas-fired combined heat and power plant being developed by Vattenfall in Germany will replace the existing power plant.
The combined-cycle power project is implemented by Gardabani Power Plant, a company formed by GOGC and Partnership Fund. GOGC controls a 51% interest and provided $120m of long-term debt finance for the plant construction, while PF holds the remaining share and provided equity financing of approximately $100m.
Gardabani power plant location and construction
The gas-fired power plant is located on 3ha of a site about 40km away from Tbilisi. It consists of two GE 6FA gas turbines, one 85MW steam turbine, two waste heat steam boilers and two natural gas compressors.
The 6FA turbines are capable of operating at a net plant efficiency of 55% in combined-cycle operations. The turbines have a nominal syngas power rating of 92MW during single-cycle operations and 140MW during combined-cycle operations. The natural gas power ratings of the turbine during single-cycle and combined-cycle operations are 77MW and 118MW respectively.
The 6FA gas turbine has a single shaft bolted rotor and is connected to the generator through a speed reduction gear at the compressor end. This configuration allows for an axial exhaust, which helps in enhancing the plant arrangements for combined-cycle applications.
The 18-stage, axial flow compressor has an ISO base pressure ratio of 15.8:1 and airflow of 203kg per second.
The 6FA gas turbine also features a reverse flow, six-chamber, second generation Dry Low NOx 2.6 combustion system with six fuel nozzles per chamber.
Transmission of power from the Gardabani plant
The transmission infrastructure includes three 100MVA main transformers and two 10MVA assisting transformers. Electricity generated at the plant is transmitted to the national grid through a 110kV power transmission line.
Turkish company Çalik Enerji was awarded the engineering, procurement and construction (EPC) contract for the Gardabani power plant.
GE was awarded the contract to supply two 6FA turbines for the 230MW combined-cycle power plant. ILF Consulting Engineers was engaged to provide engineering services for the project.
Energy sector in Georgia
Georgia is self-sufficient in terms of electricity and about 80% of the country's electricity production comes from hydropower.
The country, however, faces a major hurdle for power generation during the winter season when the water flow in the rivers is lower. This seasonal shortfall of electricity has led to the establishment of gas-fired power plants as alternative to hydro energy.
In August 2011, the Government of Georgia formed the JSC Partnership Fund to develop power projects involving the private sector. The PF holds assets worth more than GEL 5bn (approximately $2.88bn) and owns major enterprises such as the Georgian Railways, Georgian Oil and Gas Corporation, Georgian State Electrosystem and the Electricity System Commercial Operator.