GE Uses Flex Technology to Make Inroads with Efficiency and Renewables

Back in May, I wrote about GE’s new FlexEfficiency 50 power generation technology. This groundbreaking system really extends the state of the art with a high efficiency combined-cycle gas turbine system that has breakthrough efficiency and agility. The agility, which is the ability of the system to quickly respond to changes in demand, makes it ideally suited for integration with renewables, either through the grid or directly as part of an Integrated Renewable Combined Cycle (IRCC) Power Plant.

Yesterday, in Belfort France, GE announced the first commercial grid-connected FE50 project, undertaken in partnership with Electricite de France (EDF). When it comes online, it will be the world’s most efficient combined cycle power plant.

According to the press release:

The new combined-cycle plant will be located at Bouchain, an existing EDF power plant site in northern France, and will produce 510 megawatts, enough electricity for 600,000 French households. The FlexEfficiency 50 plant is the result of GE’s $500 million investment in research and development to deliver cleaner and more efficient energy.

The plant is expected to achieve greater than 61 percent efficiency at base load, which will conserve natural gas and reduce the production of greenhouse gases. Its operating flexibility will enable the plant to respond quickly to fluctuations in grid demand, paving the way for greater use of renewable resources such as wind and solar.

To put this in context, traditional steam powered electric generation plants, including most coal plants, achieve roughly 33 percent efficiency. Combined-cycle gas plants broke through the 50 percent barrier bringing significant improvements in emissions as well. GE’s new technology takes advantage of technology originally developed for its jet engine business, enabling higher operating temperatures which allow systems that exceed 60 percent efficiency. What’s more, when these systems are combined with renewables, they can achieve efficiencies approaching 70 percent.

This is exactly what will be seen in another planned project announced in June at Power-Gen Europe in Milan. In that project, GE will be partnering with Turkish developer MetCap Energy, to produce the first Integrated Renewable Combined Cycle (IRCC) Plant called Dervish (as in whirling turbines). This plant will combine a 510 MW FlexEfficiency Combined Cycle system with 22MW of Wind power and 50MW of concentrated solar thermal, to be provided by eSolar. Rated at 530 MW, this plant will provide enough electricity to power 600,000 homes in Istanbul at 69 percent efficiency.

In a subsequent announcement in November, the Dervish project size was roughly doubled with the addition of another FlexEfficiency 50 plus an additional 50MW of solar for a total of 1,080 MW.

Much of the innovation behind the FE50 comes from GE’s Jet Engine Divisions both in terms of high temperature gas turbine materials that enable higher efficiencies but also a new type of brush seal that is used on both gas and steam turbines, helping them to withstand temperature transients without leaking and thereby contributing to the agility that I mentioned earlier. The plants also have zero liquid discharge.

Meanwhile, back in France, the EDF plant will be the first of its kind to reach commercial operation, in 2015, with ground being broken in 2013. It will be joined by the Dervish plant plus two other plants that are being planned with Harbin Electric in China, plus two more with Toshiba Electric, elsewhere in Asia for a total of seven thus far.

I spoke with Paul Browning, President and CEO of GE Energy’s Thermal Products business about the progress of this new technology right after the announcement. I asked Paul about the difference between having the renewables integrated directly at the plant and to having them integrated through the grid. He said, basically, that “it depends on your point of view. If you’re a customer that just wants clean electricity, it doesn’t really matter much. If you’re the grid operator, then the fact that the solar and wind power is being firmed by the gas, you’re going to see a more reliable source of power when compared to standalone wind or solar. But if you’re the power plant owner, and if the sun is shining or the wind blowing, you’re going to see those higher efficiencies due to the contribution of the renewables.”

When I asked what GE was doing on the renewable side, he said that GE has now invested in eSolar of Pasadena, California. "They have a new generation of concentrated solar thermal technology (CST), a tower-based technology with an array of mirrors that focuses sunlight on a boiler at the top of a tower that produces steam. We use that steam to drive the steam turbine in our combined cycle power plant [as the second cycle, after the gas turbine cycle]. We really like that because when you integrate solar thermal with the combined cycle power plant, you’ve already bought the steam turbine, you’ve already bought the generator, the switchyard, etc., so you don’t have to pay twice for that piece of it, which makes solar thermal very inexpensive when it’s integrated with a combined cycle power plant. We also like the fact that the solar peak tends to be coincident with the demand peak for air conditioning ” (i.e. when the sun is shining).

GE also recently announced a smaller cousin of the FlexEfficiency 50 called the Flex Aero in the 50-60MW range.

Browning also assured me that GE does have plans to bring FlexEfficiency technology to the 60Hz (US) market. “We have not announced any timing on that yet, though we have announced our intention to do that.”

[Image Credit: GE Flexibility]

RP Siegel, PE, is the President of Rain Mountain LLC. He is also the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water.  Like airplanes, we all leave behind a vapor trail. And though we can easily see others’, we rarely see our own.

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