Aliaga Cakmaktepe is the world’s largest gas-fired power plant based on combustion engines. It is located in the Aliaga Industrial Area near Izmir in Turkey. The plant was inaugurated in September 2010 after four years of construction. It is owned and operated by the Turkey-based company Cakmakpete Energy.
The plant is currently operating six gas-engines. It is expected to become fully operational by January 2011, when the transmission lines are connected to the grid. With a generating capacity of 270MW, the plant will supply power to 350,000 households.
Electricity produced at the plant is sold to the state-owned Turkish Electricity Trade and Contracting Corporation (TETAS), which, in turn, sells it on the spot market on balancing method.
Aliaga plant
The plant features 28 Wartsila 20V34SG combustion engines and two steam turbines. Each engine has a rated capacity of 35MW.
The 34SG is a natural gas-fired, lean-burn, medium-speed engine with a high efficiency rating and low carbon emissions. It is the highest efficiency spark ignited gas engine available in the industry today. It has efficiency levels of up to 47% with a start-up of around 10 minutes.
Development
The combined cycle power plant was developed in three phases with pre-planned engine specifications. The first phase, consisting of four combustion engines, was contracted in 2006. The remaining 22 engines were developed in the second and third phases, which were contracted in 2008.
Finland-based Wärtsilä is also carrying out the maintenance work on four engines under a 10-year agreement with TETAS. These engines are a part of the project’s first phase.
Wärtsilä had subcontracted the logistics company Canship to transport 21 generators to the Aliaga Cakmaktepe Power Station. The subcontract called for offloading the engines from the vessel at Petkim Port, transport and install them at the power station.
The remaining seven engines were directly shipped to Turkey from the manufacturer’s site in Finland.
Technology
The Wärtsilä 20V34SG engine is a four-stroke, spark ignited gas engine that works on the Otto Process and the lean-burn principle. It has a ported gas admission and a pre-chamber with a spark plug for ignition. It operates at a rate of 720rpm or 750rpm on 60Hz or 50Hz, to generate 8,700KW-9,000KW of mechanical power.
The lean-burn gas engine regulates the rate of NOx formation in the internal combustion engine. The peak temperature is reduced by letting more air inside the gas cylinder. This process is controlled by the gas admission system which has valves on the top of the inlet valve that is electronically controlled to fill the correct amount of gas inside the cylinder.
The 34SG engine is controlled by an engine control system and a computerised distributed control system mounted on the engine. The electronic modules communicate via CAN ducts and are dedicated to certain functions.
The main control module is the core of the engine that keeps it operating at optimum capacity even during varying temperature and gas conditions.
Turkey power market
Electricity generation in Turkey has been dominated by conventional thermal and hydro generation sources. It is the sixth largest power market in Europe and is growing at an annual rate of 8%.
According to the Turkish Electricity Transmission Company, the country will need 20GW-30GW of additional capacity by 2016. In addition, Turkey will have to increase its name plate capacity to 40,000MW by 2020.
While the increased dependence on fossil fuel has brought the nation under criticism for damaging the environment, Turkey has also opened avenues to foreign investors in the energy sector due to abundance of natural resources.
The sector has witnessed an investment of more than $10bn in 2010.
The other major reason for the growth of the energy sector is the structural change of the regulatory market through the establishment of an Energy Market Regulatory Authority (EMRA).