In order to convert coal energy to usable electricity, the integrated gasification combined cycle technology is often used (Eden, 1981). It is one of the most thorough and environmentally sustainable methods which have been adopted in the conversion process. The electric power stations which make use of coal gasification technology is used in New Zealand. This technology has also been considered to be the best option in future because it will enable clean conversion of coal to electricity.
The principle behind coal gasification is the disintegration of coal using heat energy into its constituent chemical elements instead of direct combustion of the mined product. Steam is directed towards coal and regulated amounts of oxygen follow. The physical conditions of temperature and pressure are equally kept high during this process. As a result, the molecules which make up coal are broken down which is then followed by a series of reactions generated chemically. Finally, hydrogen, carbon monoxide and other gases are produced (Trinnaman, 2004). On the other hand, the stream cycle receives the surplus heat which has been generated during the process of combustion. This is synonymous to what happens in a combined cycle gas turbine. There is a high level of efficiency achieved using this technique than the traditional burning of coal to generate energy.