What is the Difference Between Gas Turbines and Steam Turbines?

Steam turbines and gas turbines are the two pillars of a power plant. Both of them use the principle of thermodynamics and together they perform at ideal efficiency. 

The main work of both gas turbines and steam turbines is to transfer mechanical energy into electrical energy. Both have two different apparatus and two different mechanisms of working. But the motto is power supply.

Nonetheless, there are some major differences when it comes to steam and gas turbines. For example, the thermal efficiency of gas turbines is 20 to 26% lower when compared to steam turbines. Now, let us dig a little deeper into the differences between gas and steam turbines one by one.

Gas Turbines

For starters, gas turbines receive power from a combustion reaction. The fossil fuels provided combines with the compressed air and combust which produces exhaust gases that are extremely hot. These gases contact the turbine blades which cause them to rotate and produce electricity. The air that is ingested into gas turbines produces a very loud noise. This noise is controlled by the inlet silencers of the turbine. When the air comes out of the combustion engine, it makes the same loud noise which is then controlled by exhaust silencers. 

Further, the essential components in the gas turbines include the upstream air compressor, the combustion system wherein the reaction occurs, and the turbine blades that rotate when the hot gas makes its way into the posterior area. 

Turbines like MDA turbines along with steam turbines are the basic elements that produce electricity and energy. However, both require different apparatus and operating conditions that provide maximum performance. 

The air in the combustion system can be as hot as 1,500 degrees Celsius that is comparatively hot by a huge margin than the air in a steam turbine engine. The benefit of gas turbines over steam turbines is since the core is not water as the central process, the risk of the process being interrupted due to internal freezing is minimum. On the other hand, since gas turbines use fossil fuels as the core component, the process creates harmful pollutants such as nitrogen oxide

Steam Turbines

When it comes to steam turbines the main difference between gas and steam turbines is the fact that steam turbines are powered by expanding steam. The fuel is used to heat the water which is condensed that is provided in a boiler. One of the alternatives to fuels is renewable thermal energy is also possible for this heating; however, it is very time-consuming.

The heated water turns into steam which turns the blades of the steam turbine to create power. The internal temperatures reach up to 500 to 650 degrees Celsius, which is less than half of the temperature of gas turbine reactions.

This water-based cycle is called the Rankine Cycle. Unlike gas-powered turbines, steam turbines do not have any air compressor or combustion system, but instead, have a boiler and rotors that transfer thermal energy into mechanical energy and a casing area that makes sure the steam comes into contact with the blades under pressure. 

The centrality of water means there is a risk of freezing of water internally, but steam-powered turbines allow for a clean and safe alternative for the creation of energy if renewable energy is initially used to heat the turbine’s cycling water.

To sum up, the difference between gas turbines and steam turbines is explained in the table below: 

Gas turbinesSteam turbines 
The essential components are the compressor and combustion chamber The essential components are accessories and a steam boiler 
The sum total mass of gas turbine per kilowatt is less developed The sum total mass of steam turbine per kilowatt is more developed 
The installation of a gas turbine requires minimal space The installation of a steam turbine requires more space as compared to gas turbines 
Cost-efficient with respect to installation The cost maybe more with respect to installation 
The ignition of gas turbines is relatively easyThe ignition of steam turbines can be a difficult process 
Control of gas turbines is easyControl of steam turbine is hard 
Dependence on water supply is less Dependence on water supply is more 


To conclude, there are pros and cons to both the turbines, howsoever they are used in different fields and have a different area of expertise even though the core reason for their existence is power supply. Gas turbines are used in aircraft as well unlike steam turbines which predominantly rules over inducing electrical energy.