Taking a look at Combined Cycle Gas Turbines in the Energy Mix

CCGT is a marvel of technology, science and engineering - Combined Cycle Gas Turbines convert energy into electricity in a highly efficient process. It’s part of a combined cycle plant and a wider power grid that generates, transmits and distributes power to our homes and businesses.

Combined Cycle Gas Turbines are an efficient use of energy and its distribution where the gas turbine uses a process of combining highly heated compressed air and fuel to create a motion of power to a generator and in turn convert energy into electricity.

Understanding how CCGT works helps understand why it is considered more efficient: the key is the multiple use of heat engines (fuel/source may differ) in staged synchronisation with one another converting into mechanical energy and then electricity via a generator. This ensures a reduction in fuel costs and means capacity can be reached quickly when required. CCGT Plants are not a single-use scenario for the power grid - being online in relatively quickly (generally under one hour) means that beyond a constant state of power distribution they can also be used during peak demands. This tends to be the case where the reliability or timeframe of other resources can be an issue, for example where wind or solar are not guaranteed at a given point and leads into the area of energy storage. The type of fuel and specific process affects the efficiency of converting energy, from an average of 30% for a simple cycle gas turbine to as high as 64% for a combined cycle. The energy that is ‘wasted’ during the process is known as latent energy – the majority of which is actually thermal energy from combustion released via exhaust gases.

CCGT is a smart solution to utilising waste energy: the system capture the waste thermal heat to create steam from the exhaust gases. The high temperatures create the perfect conditions for steam via a steam turbine, creating more electrical power without needing additional fuel. The harvested energy created by the steam turbine(s) can actually account for up to half of the plant output.

With a shift towards ensuring renewable sources are utilised and reductions in CO2 emissions are met, it is inevitable that CCGT will continue to grow in importance in the wider Energy mix.

For cables supporting applications in CCGT plants, see our Transmission and Distribution page or talk to our technical team for a tailored solution.