Power stations that use gas turbines as their primary energy conversion system have in recent years become one of the mainstays of the power generation industry in the developed world and have also made inroads in the developing world. These high-technology engines can burn a range of liquid and gaseous fuels but most commonly they are fired with natural gas and their success depends primarily on its cost and availability.
The current prominence of gas turbine technology is a striking position to have achieved for a technology that until the late 1980s played a small part in global power generation. Several factors have conspired to bring about its success. First was the recognition of natural gas as a valuable fuel rather than a by-product of oil production, which was best disposed of by flaring at the well head. Though some natural gas is still flared, the fuel is now a vital part of the global energy economy, particularly through its use for power generation.
The cost of natural gas was a second factor in its initial rise in popularity.
This was particularly true in the early 1990s when it was cheap in many developed markets. Since then the price of natural gas has become one of the most volatile among power plant fuels and the economic viability of gas turbine power generation has waxed and waned with its cost.
A third, and perhaps the overriding, factor in the success of gas turbine technology has been the development and continual rise of the gas turbine combined cycle plant. Combined cycle plants are one of the cheapest types of power- generating facility to install and the best modern examples can demonstrate energy conversion efficiencies of 60%, higher than any other large-scale fossil fuel–fired power plant in operation today. This, together with the fact that the combustion of natural gas produces significantly less carbon dioxide and less of most other pollutants than coal combustion, has made the gas turbine an attractive addition to the armory of electricity-generating technologies.
The role of gas turbines may become more important still. The International Energy Agency (IEA) suggested in 2011 that the world could be entering a golden age of gas, a development that would benefit gas-fired power generation significantly. The IEA proposition depends on the coincidence of the pressing global need to reduce carbon dioxide emissions,1 the concomitant rise in the use of fluctuating sources of renewable generation such as wind and sun, and the sudden improvement in natural gas availability brought about by shale gas exploitation.
The ability to exploit shale gas economically has led to a sharp rise in the availability of natural gas in the United States and a consequent fall in the cost of the fuel. The trend is expected to spread to other regions as shale gas explo- ration expands. At the same time, the flexibility of combined cycle power plants burning natural gas makes them an ideal alternative source of power to help balance the varying generation from renewable sources. Thus, the use of wind power and solar power, together with gas-fired combined cycle power plants, is seen as a compelling combination for the future of power generation in many regions of the world.
Taken together all these factors could see the use of natural gas as a source of electricity double between 2008 and 2035. Based on figures from the U.S. Energy Information Administration it could account for 24% of global electricity generation in 2035. While this would be lower than the proportion of generation from coal, it would represent slightly more than the total from all renewable sources.