New fracking practices have increased the availability and decreased the cost of natural gas. This is having an enormous impact on energy systems around the world. There are numerous potential applications for natural gas including, but not limited to, use for transportation fuel, residential use, and electricity generation. Since the economic potential of exploiting this resource is so large it is likely that Canada, along with the US, will continue to ‘frack it all’ and reap the economic benefits on the global market. Other countries like China are joining in as well.
The largest increase in use of natural gas is for electricity generation. Natural gas fired power plants are appealing for many reasons. They can supply reliable base-load as well as peaking power. Also, they can be planned and built in less time than say, nuclear power stations, and for lower capital cost. Since fuel is available and cheap, natural gas power plants will continue to be built, and existing plants will continue to operate.
Consider though: combustion of natural gas emits greenhouse gases, and GHGs contribute to global warming. So, if we are going to use this fuel for electricity generation, we better ensure we use it efficiently.
How can we do this? Combined cycle power plants may be part of the answer.
Combined cycle power plants use a gas and a steam cycle to generate electricity from a single fuel source. High temperature waste heat from the exhaust gas exiting the gas turbine is used to generate steam which is passed through a steam turbine. For this reason, combined cycle power plants are more efficient than single cycle gas or steam power plants. Essentially, these plants give you more ‘bang for your buck’. Quite literally; since around 75% of lifecycle costs for natural gas power plants are the cost of fuel, efficient use of natural gas means cost savings as well as reduced GHG emissions.
Compared to single cycle steam or gas power plants, combined cycle facilities are more environmentally friendly and economically appealing. As we replace coal-fired power plants and build new generation capacity with natural gas power plants, combined cycle power plants are definitely a technology to consider. Sustainability of urban development globally needs many advances in many areas, combined cycle technologies is one such advance.
This is third in a series of blogs on energy issues written by 4th year energy systems students from the University of Ontario Institute of Technology in Oshawa, Ontario. (See blog by Dan Hoornweg introducing the series.)