Natural Gas: The Preferred Fuel for Electricity Generation
The world’s energy diet has undergone a dramatic change since the 1990s as more and more countries are shifting to natural gas as the preferred fuel for electricity generation. Coal and nuclear energy were the preferred sources for power plants. However, environmental, technological and economic factors have resulted in natural gas gaining the upper hand.
Falling prices of natural gas was the driver for this sentiment. But environmental considerations including expected carbon legislation in Europe and US are helping speed up the migration from coal to natural gas for power generation. While nuclear power is cleaner than natural gas, the prohibitively high costs of setting up a nuclear power plant have discouraged most countries. This in turn has led to more companies and countries opting for natural gas.
The statistics say it all. Coal-based facilities in the US are expected to slip from 18 percent in 2009 to 10 percent in 2013. In Europe, new capacity building was 24 percent for natural gas and 8.7 percent for coal in 2009.
Coal Vs Natural Gas
Efficiency: Over the years increasingly sophisticated technology has pushed up the efficiency rates of natural gas run power plants. Until 2000, the efficiency of coal and natural gas based plants were more or less on par and was estimated to be between 32 and 34 per cent. What this means is that out of the total fuel used, only around one-third was converted to electricity; the rest of the fuel was simply blown out as unused heat. The consequences of these statistics for a resource-starved planet were rather grim.
However, post-2000, new technology was introduced in natural gas power plants. The “combined power” natural gas power plants began to operate with higher rates of efficiency. Today, the average efficiency of a natural gas based power plant is 44 percent in the US. The efficiency of coal based plants remains stuck at 32 to 34 percent and it takes 60 percent more coal than natural gas to produce one kilowatt-hour of electricity.
Economy: Coal is still the cheapest fuel available. That is why India and China are still dependent on coal to a great extent for their power generation. But in a world that is demanding greater environmental accountability, the costs of running coal plants are likely to keep on rising. For example, in western developed countries, environment regulations ensure that coal based plants have to install pollution control measures to clean up the mercury and other toxic elements left behind in their exhausts. In addition, coal extraction and transportation costs are also on the rise. A report by Barclays Capital estimates that 42 Gigawatts of coal based plants that use antiquated technology will close down by 2015.
Environment: Power generation is an extremely polluting business. In its 2002 report “Cleaning up Air Pollution from America’s Power Plants”, the Pew Charitable Trusts (PEW), estimated that power plants in the US account for 67 percent of sulphur dioxide emissions, 40 percent of carbon dioxide emissions, 25 percent of nitrogen oxide emissions, and 34 percent of mercury emissions. Coal fired power plants are the greatest contributors to these types of emissions. As one of the cleanest fuels, natural gas rates much higher than coal. In fact, according to World Watch Report 184, natural gas combined cycle power plants emit half as much carbon dioxide as modern super critical coal plants. It also eliminates mercury emissions.
These figures hold great significance for India as well. Given that coal is more abundant than natural gas in the country, we have focused more on coal based power plants. At the same time, we have also pledged to reduce carbon emissions by 20 percent from 2005 levels by 2020. With the development of a natural gas infrastructure, the shift to natural gas power plants like the proposed Cheemeni power plant at Kasaragod in Kerala can help achieve these environmental targets.