Gas power generation (GPG) has increased significantly in the past few years, with gas overtaking coal in most countries outside southern africa.
Gas power generation (GPG) offers greater efficiency and lower CO2 emissions than coal, as well as other operational advantages.
Advantages of gas for power generation.
• Construction time:
Gas turbine power plant is far less complex that coal fired and hence has shorter construction times and typically less than 24 months with standard off-the-shelf designs being the norm for gas power stations.
• CO2 emissions:
Gas powered plant has approximately 40% less CO2 emissions per unit of power than coal, due partly to greater efficiency, but mainly due to the hydrogen content. This is a great advantage over carbon taxes.
• Capital costs:
According to a study done by the NREL, gas power capital costs are about 40% of the equivalent coal fired cost.
• Flexible output:
Rapid start-up, ramp-up and ramp-down times enable gas power systems to follow variable and rapidly changing generation patterns of renewable energy sources.
• Prefabricated modular design for significantly faster installation
• Competitive, reliable power generation
• A scalable solution that grows as you need it
• Re-deployable for use elsewhere
• Easy integration with renewable energy and storage systems
• Fuel flexibility
As an example consider how much gas would be required for base load generation of 1000 MW using a CCGT with the following parameters:
• Net heat rate = 6500 kJ/kWh = 6500 MJ/MWh = 6 500 000 MJ/GWh
• Calorific value of natural gas =9,8 kWh/m3 or 35,2 MJ/m3
• Gas required per annum at 90% duty cycle = 1 464 171 428 m3
• If MW = 250; 3.6 x 250 = 900 GJ/h