"It's not a low-carbon technology, but it could be part of a low-carbon system."

There are no technology solutions to the climate change problem. There are, however, systems solutions. (GW)

A Gas Power Plant to Make Renewables More Practical

GE says its new gas-plant design can address the sudden drops that occur with renewable forms of energy.

By Rob Edwards
Technology Review
May 27, 2011

General Electric announced on Thursday that it's designed a gas-fired combined-cycle power plant that can start up rapidly. The goal is to help electricity grids adapt to the variability of renewable energy.

With a small but growing proportion of electricity in Europe being supplied by wind and solar power, grid operators need new ways to deal with fluctuations in supply. The supply from solar drops dramatically at night, while wind installations only provide power when the wind is blowing. GE's new plant can ramp up electricity generation at a rate of more than 50 megawatts a minute—twice the rate of current industry benchmarks. The plant can start from scratch in less than 30 minutes.

GE is testing a pilot plant at its facility in Greenville, South Carolina, but the plant won't come into operation any earlier than 2015.

The plant will have a base load fuel efficiency of 61 percent, higher than other gas combined-cycle power plants. A base load power plant is one that's dedicated to providing a continuous supply of energy. Nuclear and coal plants commonly provide base load power. Such plants offer relatively cheap energy, but they can take hours or days to start up, which isn't fast enough to meet fluctuations in supply from renewables.

GE's 510-megawatt plant design is the result of a $500 million investment by the company. It features new, more efficient gas and steam turbines, as well as a new integrated electronic control system.

Paul Browning, vice president of GE Thermal Products, said at Thursday's announcement that the plant uses nickel-based super alloys, which are used in aircraft engines, because they can withstand the high temperatures inside the plant. The new turbines can ramp up quickly, much as a jet engine can ramp up quickly to provide thrust for takeoff.

GE estimates that the new technology could save some power utilities $2.6 million a year under typical operating conditions. The company also says the plants could cut annual carbon-dioxide emissions by more than 12,700 metric tons, with an annual fuel savings of 6.4 million cubic meters of natural gas.

The new plant has a power frequency of 50 hertz, meaning it can be built in Europe and many other parts of the world, but not in North America. GE says it will announce a 60 hertz version for the U.S. market at a later date.

Jim Watson, director of the energy group at Sussex University, says he's impressed by the enhanced flexibility of the plant. "This is just the kind of plant we need," he says. "It's not a low-carbon technology, but it could be part of a low-carbon system."

Copyright Technology Review 2011.