Environmental Engineering Reference
In-Depth Information
Condenser
Pump
Steam turbine
Boiler/
heat exchanger
Electric
generators
Gas turbine
This simple diagram shows how a gas turbine generator generates electricity.
The waste heat is used to make steam to generate additional electricity via a
steam turbine.
used to make steam, which can turn a steam turbine to make additional
electricity.
Transport
Gas also has some important drawbacks, one of them being the relative
difficulty of its transporting it. At the point of actual electricity gen-
eration, gas-fired power plants are cheaper and quicker to construct than
coal-fired power plants, and much cheaper and quicker to build than
nuclear reactors. But transporting a gas is more complex and expensive
than transporting a solid such as coal, or a liquid like oil.
Granted, a pipeline for gas may be no more expensive, in absolute
terms, than a pipeline for oil. But the pipeline for gas is more expensive
relative to the lower energy density of the gas, compared to oil's high
energy potential. And shipping gas is more expensive in absolute terms
than shipping oil or coal, because the gas has to be cooled into a liquid
that is 1/600th of its gaseous volume before eventually being re-gasified at
its destination. This is why gas deposits are described as “stranded” more
often than oil or coal deposits: it is not that gas is necessarily found in
more remote places than oil or gas: it is just that getting gas to its destina-
tion is more of a problem than for oil and coal.
