As reported in Part 1 of this blog, Forecast International’s team of industrial and marine turbine specialists was given the opportunity to tour a facility that operates two General Electric 7HA.01 gas turbines and a General Electric steam turbine. The Towantic Energy Center, located in Oxford, Connecticut, is a prime example of what is currently state-of-the art for this type of powerplant. Questions asked by Forecast International’s team were readily answered by the plant manager, and much was learned in the process.
In terms of efficiency, TEC’s combined-cycle plant runs at over 60 percent. Efficiency is not the only impressive aspect of these large turbines. Maintenance and inspections are generally conducted biannually, whereas other turbines may demand more frequent attention. The 7HA.01 was not the only topic of conversation. How power was distributed and sold was also discussed.
The process of generating electricity is ongoing, and there are many companies supplying power. A turbine’s efficiency and total output is dependent mainly on the ambient conditions at a particular site. It is therefore necessary to submit potential power production information daily to a central authority. That authority then allows market participants to lock in a fixed price for the following day. This is known as a wholesale energy market, and it is how power is sold in New England.
Baseload, or the minimum level of electricity demand on a particular grid, is first allotted to coal and nuclear facilities. Natural gas plants can be baseload power producers, or “peakers,” that provide power when there is high demand. Gas turbines are also handy in supporting renewables, such as wind and solar, that produce intermittent energy.
Combined-cycle plants are not perfect
The Towantic plant that Forecast International visited does have its drawbacks. It is located within earshot of residential housing – when steam is released, the noise can be significant. In order to mitigate that sound, noise dampeners will be installed. Another issue is the aesthetics of a power plant – it is generally not attractive to the eye. Short of rendering the plant invisible, great care was taken in choosing a design and colors that lessen its visual impact.
The opportunity to visit such a modern powerplant was a memorable learning experience. Forecast International thanks the Towantic team for its guidance and cooperation.
Be sure to visit Forecast International power systems analysts Carter Palmer and Stu Slade at Power-Gen International on December 4th through 6th, Booth 1360
As an analyst for Forecast International’s Industrial & Marine Turbine Forecast, author Carter Palmer specializes in examining key gas turbine programs for electrical power generation, mechanical drive, and marine propulsion applications.