A gas turbine plant is one that uses natural gas to produce electricity. In most cases this is done by using heated steam to spin a turbine. This is the third most common way in which to produce electricity. The environmental benefits may be one reason why it continues to be in the top three. At the same time, renewable power plant electrical generation is a close fourth, and is likely to continue to gain momentum as the technology improves.
The natural gas turbine plant normally works by heating water in a boiler. This creates steam, which is then channeled through a smaller area to a turbine. The turbine spins from the pressure the steam creates, generating an electrical current through the use of electromagnets. This electricity is then transported by wires from the gas turbine plant to another location, most likely a customer of the plant. The method is generally only able to convert approximately a third of the heat created into electricity, meaning it is very inefficient.
One way to improve the efficiency of a gas turbine plant is to build a hybrid plant, using not only traditional steam, but also centralized gas turbines. This is called a combined cycle unit. First, the natural gas power plant uses the heat created from the burning of the fuel to turn a gas powered turbine directly. Then, the unused, or wasted, heat is used to generate steam to help turn another turbine. By combining these two processes, the efficiency can increase to as much as 60 percent.
Despite these advances in efficiency, the gas turbine plant is still a relatively rare method of generating electricity. Coal is the leader, probably because the source is so plentiful and cheap. Nuclear is next in line, probably because it is clean and cheap, once the plant is built. Still, there are some advantages to the gas turbine power plant.
These advantages often come down to cost and cleanliness. A gas turbine plant produces approximately 55 percent of the carbon dioxide produced by a coal plant to generate the same amount of electricity. Further, there is no mercury produced, and only one pound of sulfur dioxide. A coal plant, by comparison produces nearly 2,600 pounds of sulfur dioxide and trace amounts of mercury, per billion BTU of energy output.
There are some disadvantages to a natural gas turbine plant as well. In most cases, the price of natural gas can be quite volatile, especially during the winter months when the fuel is in higher demand due to space heating. For this reason, coming up with a cost, both for the utility company and consumer, can be a difficult thing. This can lead to very large disparities in budgeting, and wide fluctuations in price.