The second law of thermodynamic is a natural law, indicates that, although the net heat supplied in a cycle is equal to the network done, the gross heat supplied must be greater than the network done.
In other way, no matter what, there will always be losses in any thermodynamic system which we are reliant upon in generating our electricity, using boilers to produce steam and run turbines. One tonne of black coal will produce 27 GJ of energy that transferred to steam as heat energy and about 2.4 tonne CO2-e.
1 KWh =3.6 MJ, that means the 27 GJ should produce 7.5 MWh, but more likely you would get one third at the end, because two third of the 27 GJ would be lost in the system in form of heat and friction losses. So we burnt one tonne of coal to get one third of energy and emit 2.4 tonne co2-e. as a carbon manager, it is important to be familiar with energy numbers and how they make sense, as I always say, energy is the currency of carbon.
Industrial countries have become increasingly energy conscious with the recognition of dangers to their energy supplies and the rapid increases to their own energy demands. The unpopular use power plants based on fuels which are polluting the environment such as coal and others with poisonous waste such as nuclear; the continued increase in the price of fuels and the subsequent effect on the cost of doing the business and general cost of living is of economic importance to all nations. This general concern has led to continuous assessment of the energy problem with the view to improving the efficiency of utilisation of established form of energy and to seek new sources.