Over the last 20 years, the use of natural gas to generate electricity has been growing at a higher rate than many other energy sources. That trend is expected to continue as natural gas plants are eyed as for a prime role as load balancers as more renewable energy sources are added to electric grids.
Natural gas plants have several attributes that make them well-suited for this role as load-balancers. For example, they can quickly throttle electricity production up and down to meet changing loads.
Focusing in on this aspect of complementing renewable generation capacity, General Electric recently announced it had designed a new gas-fired combined-cycle power plant that could start up rapidly, and also offered higher efficiencies than traditional natural gas plants. GE is testing a pilot plant of this design at its facility in Greenville, South Carolina.
According to reports, the new plant can go from shut down to start in less than 30 minutes. Additionally, it can increase electricity generation by 50 megawatts a minute, which the company claims is twice the rate of current plants.
One of the key features of the new plant design is more efficient gas and steam turbines. The turbines use technology developed to improve the performance of jet plane turbines. This includes tightly integrated electronic control systems and the use of new materials. For example, the turbines use nickel-based super alloys, which are used in jet aircraft engines. The advantage of using this material is that it can withstand higher temperatures and this in turn allows the plant to throttle up faster without damaging turbine components.
The design improvements result in a plant that will have a base load fuel efficiency of 61 percent, which is higher than that offered by existing gas-combined cycle power plants.
According to GE, the new technology in the new plant could save some power companies $2.6 million a year under typical operating conditions and cut carbon dioxide emissions by more than 12,700 metric tons a year.
The current pilot plant offers a power frequency of 50 hertz, which is the frequency used in most parts of the world, but not North America. GE says it will announce a 60 hertz version for the U.S. market at a later date.