Gas turbine - combined cycle (GTCC) power plants produce electricity using a combustible fuel, a gas turbine and a generator. Also included is a steam turbine and generator using heat recovered from the gas turbine's exhaust gas via a heat recovery steam generator (HRSG). In addition to producing electricity, useful heat can also be recovered from the steam turbine extraction port and back pressure port, and this recovered "waste" heat can be provided to a heating load. In this latter case, the GTCC power plant would be operating in a Combined Heat & Power (CHP) or cogeneration mode. The energy performance of a gas turbine – combined cycle power plant is influenced by a number of factors such as the type of fuel, the gas turbine power capacity, minimum capacity, availability, heat rate and heat recovery efficiency. Other factors include the steam turbine operating pressure, superheated temperature, back pressure and efficiency. And the energy performance of a gas turbine – combined cycle power pant will also be influenced by the use of duct firing on the gas turbine, the presence of an extraction port on the steam turbine and the return temperature. Refer to the Gas Turbine - Combined Cycle Schematic for more information.

Software & Data
The RETScreen Software Gas Turbine - Combined Cycle Model can be used worldwide to evaluate the energy production and savings, costs, emission reductions, financial viability and risk for central-grid, isolated-grid and off-grid gas turbine - combined cycle projects, ranging in size from large scale natural gas-fired multi-turbine central power plants, to distributed power systems located at industrial facilities. In addition, landfill gas production can be estimated using an advanced landfill gas tool, and a biogas tool is provided to calculate the amount of biogas produced by the biological decomposition of various wastes. The software (available in multiple languages) also includes product, project and climate databases, and a detailed user manual.

Click here to download RETScreen 4 (36 MB).

Case studies / Templates
Heating & power - Gas turbine - combined cycle - 8,200 kW - Landfill gas / UK
Power - Gas turbine - combined cycle - 126,000 kW - Natural gas / Japan
Power - Gas turbine - combined cycle - 260,000 kW - Natural gas / Canada