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New GE combined cycle power plant delivers both flexibility and efficiency; enables greater use of wind, solar and natural gas on grid

GE unveiled the FlexEfficiency 50 Combined Cycle Power Plant, engineered to deliver a combination of flexibility and efficiency in power generation. GE drew from the company’s jet engine expertise to engineer a single-shaft plant that will ramp up at a rate of more than 50 megawatts per minute, twice the rate of today’s industry benchmarks. By rapidly ramping up and down in response to fluctuations in wind and solar power, the technology will enable the integration of more renewable resources into the power grid, GE says.

The FlexEfficiency 50 Combined Cycle Power Plant. Click to enlarge.

The FlexEfficiency 50 Combined Cycle Power Plant is rated at 510 megawatts and offers fuel efficiency greater than 61%. The plant is the result of an investment of more than $500 million in research and development by GE; it is a key part of ongoing work to create and manufacture technologies around the globe that deliver cleaner, more efficient energy, the company said.

While power plants today can provide flexibility or high efficiency, this power plant will deliver an unprecedented combination of both. Operational flexibility at these levels will enable utilities to deliver power quickly when it is needed and to ramp down when it is not, balancing the grid cost-effectively and helping to deploy additional renewable power resources like wind and solar. A typical FlexEfficiency 50 plant will deliver enough energy to power more than 600,000 EU homes.

GE engineers were able to avoid the typical tradeoffs between flexibility and efficiency by approaching the plant design from a total equipment and control systems perspective. The FlexEfficiency 50 plant is engineered for flexible operation by integrating:

  • A next-generation 9FB Gas Turbine with a new four-stage hot gas path that operates at 50 Hz (the power frequency that is most used in countries around the world).

  • A 109D-14 Steam Turbine, which runs on the waste heat produced by the gas turbine. The steam turbine features a double flow side exhaust low pressure (LP) configuration and synchronous clutch.

  • GE’s advanced W28 Generator with water-cooled stator.

  • Heat recovery steam generator.

  • Mark VIe integrated control system that links all of the technologies.

The International Energy Agency concluded in a new report that large shares of variable renewable energy are feasible as long as power systems and markets are properly configured so they can get the best use of their flexible resources.

As our customers seek to increase their use of renewable energy, the challenge of grid stability sharpens. They are under added pressure to achieve higher levels of efficiency and lower emissions for natural gas power plants. The FlexEfficiency 50 plant creates an immense growth opportunity in a new segment for our gas turbine technology and is in lock-step with our commitment to build a cleaner energy future.

For years we have been working to develop technology that can, in the same breath, deliver breakthrough efficiency and deal head-on with the challenge of grid variability caused by wind and solar. The need for combined flexibility and efficiency is even more pressing today as countries around the world establish new emissions standards.

—Paul Browning, vice president thermal products for GE Power & Water

The FlexEfficiency 50 plant is the first product in GE’s new FlexEfficiency portfolio and part of GE’s ecomagination commitment to drive clean energy technology through innovation and R&D investment. The launch follows GE’s recent announcements of the world’s most efficient wind turbine, the highest reported efficiency for thin film solar and $11 billion in acquisitions that strengthen a portfolio supporting natural gas and power transmission.



"The FlexEfficiency 50 plant is the first product in GE’s new FlexEfficiency portfolio and part of GE’s ecomagination commitment to drive clean energy technology through innovation and R&D investment. The launch follows GE’s recent announcements of the world’s most efficient wind turbine, the highest reported efficiency for thin film solar and $11 billion in acquisitions that strengthen a portfolio supporting natural gas and power transmission." WOW


Now they are talking! This is a wise use of fossil fuels - as a backup to wind and solar instead of the other way around. Wind and solar should be "baseload" power since they are not particularly easy to turn on and off, up and down (not "dispatchable" in gridspeak). Then, use natural gas to supply the peaks and/or fill in when the wind dies. Or buy these CC plants now for baseload, and then convert to peaking power as more wind and solar comes on line.

Stan Peterson

I welcome the development of combined cycle "grid following" plants. For this to be useful, I suspect the output is small, to be able to react fast, only a few hundred megawatts at best. But then all the installed wind is tiny. But even so is highly destabilizing to the grid.

This is an example of throwing good money after bad, in the name of politically correct pseudo-Science. But Utility commissions having been brow-beaten into the ground, to erect "white elephant" wind mills.

They need an avenue to actually allow them to operate, without creating grid stability problems leading to blackouts, like they do. So it may prove to be an easy sell for such purposes.

Not that it was necessary in the first place. It is akin to amputating an arm to remove a hangnail, and then being offered a custom set of bandages developed expressly for auch hangnail amputations.


I high efficiency, high rate change gas turbine is very useful for places where they want to attach a lot of wind.

However, it increases the capital cost of building the grid (or rebuilding the grid).

Initially, you have a grid and generation for a certain population size. All is well, if rather carbon based.

Then, you are mandated to add a certain amount of wind power (or solar), both of which are intermittent and uncorrelated with each other or demand.

So you cannot close any of the old plant, because there will be days when there is essentially NO wind ( say < 5% of capacity).

With these, you can replace the "old" gas turbines with ones which can follow demand faster, but you still have to keep 100% coverage for when there is no wind.

So you can add quite a bit of wind into your grid, Ireland has 1300 MW of 5000, but you can't shut down any old plant, and you have the option of replacing older fossil generators with these faster ramping ones to reduce the chances of blackouts.

It is good, but it is not VERY good.

You get to reduce the carbon intensity of your electricity, but at huge capital cost.

(and high running cost, as you have to keep two sets of people employed to operate the fossil and renewable power sources.

richard schumacher

For less than $0.20 per kW-h delivered we can be carbon free. That is a small price to pay.


As innovative as these advances in traditional power plant adaptation are... we need to do better. This evolution provides the argument to do so. As mahonj points out the carbon reduction comes at a huge capital cost. And richard's prediction of $0.20/kWh is unrealistic.

We might consider these load following wind/solar schemes a first phase in the energy independence evolution. But we can lower the huge capital cost by implementing a simultaneous emphasis on distributed energy. As grids are converted to renewables with load following combined cycle plants - we need to begin installation of CHP appliances in the single and multiple family residential sector.

PHASE ONE: grid conversion to NG combined cycle, renewables, licensed nukes and thorium, AND NG-fueled CHP appliances in residences.

Without the CHP component we stay on the slow track married to century old transmission systems. GE(or other manufacturer) needs to hedge these investments with CHP/water heater appliances that will allow shut down old fossil plants.

Deterrence from the distributed path will only speed the introduction of Mills and Rossi-type disruptive technology. This is a plan to expand the entire energy portfolio by steady integration of new systems.


There is a lot of waste heat from all power plants. Why not use that heat for distilling ethanol or process heat for other plants. We waste more than half of our energy and then wonder why we do not have enough.


Right on Orbrid. Solar and Wind (and other intermittent power sources) have to supply base loads. Controllable power sources such as Hydro and quick ramping up Gas turbines such as these, have to be used for peak demands and periods with lower wind and solar power production.

Unfortunately, Hydro, Nuclear, Coal fired power plant engineers do not want to become second class-place power producers and continue to make Solar and Wind power integration as difficult as they can. Resistance to change is very deep in those groups.


Harvey, you're right about traditional power plant *owners* - not engineers. They resist seeing the opportunity in change. There is an estimated $2.5Trillion in distributed energy systems worldwide. Each CHP water heater/generator has to be manufactured, shipped, installed, tested and maintained. A HUGE new industry creating hundreds of thousands of new JOBS.

Old school central power plant owners have yet to grasp the enormous opportunity staring them in the face. Why? Entirely a lack of vision. Where centralized energy has been viewed a political power play - de-centralized energy is mistakenly seen as competition. But only for those who refuse to adapt.

Energy principles that embrace the new power structure will win and win BIG. They will have control of manufacturing and maintenance of millions of CHP systems. Add some after market subscription services (micro-grid backup, smart-grid energy swaps, etc) - you have a model for a robust worldwide business.

It's all about vision now.


I've always liked the idea of CHP, but improvements in air source heat pumps mean they aren't always the best option.

10kWh of gas in CHP - would give you 3kWh of electricity + 6kWh of heat (assuming 30% electrical efficiency and 60% heat recovery)

10kWh of gas to 60% efficient CCGT = 6kWh electric, say 5.5kWh after transmission. You would then have 3kWh for electric and 2.5kWh for a heat pump. With a COP of 3 that would give you 7.5kWh of heat

Although you arguably get advantages from CHP in grid loading and reliability so the case is by no means closed.


We have been investing in central plants for more than 100 years. Many coal fired power plants are more than 50 years old and still running. This makes money, it is proven to make money, to think that a large percentage will become distributed any time soon is not probable.

All I know is the plants in operation reject a LOT of heat. 10 miles down the road, there will be a process plant that will generate heat with coal or gas. Combine those two efforts and save energy. That is obvious, but in a go it alone attitude we continue to waste energy.


3Peace - the example you provide indicates 2.5kW
electric for heat pumped to 7.5kW (COP 3) heat dependent on air temperature differential. Thermal efficiency of a heat pump drops significantly as the outside temperature falls.

Our local CHP unit delivers 3kW electric at near zero loss, and 6 kW of heat for home heating and hot water. Likely best CHP applications are in cooler climates.

Added benefit of CHP is less load on grid, a LOT less maintenance on grid transmission systems. A LOT less environmental impact to landscape, wildlife, appearances, cost of easements and right of ways. A LOT less cost stringing and burying cable.

Distributed energy also delivers the lowest security risk of any energy system. If a central power plant is damaged - its grid goes down. Distributed energy provides thousands of sources combined into micro-grids to serve neighborhoods and communities. MUCH more secure. Of course the entire game changes with new fuels and catalysts providing CHP input energy.


The situation is very different in many places. Our area has 45,000 MW of Hydro installed and our average 24/7 use is around 22,000 MW. Peak loads are close to 40,000 MW. Another 40,000MW of Hydro power can and will be installed in the next 3 or 4 decades. Installed wind power is only 2,000 MW and increasing slowly. The total (on shore) wind power potential is 90,000+ MW. Our regional Hydro people refuse to invest into co-located wind power because it represents a major from Hydro plants. High quality winds are not currently harnessed but that could change if Hydro management is changed. Hydro/Wind combo are ideal where they co-exist, specially when you make wind the base load power.


Hydro-rich territories like Canada will continue to sell energy to those in need of a reliable, sustainable resource. But the value of that energy will decrease as localized renewables expand. Never-the-less, hydro, solar and wind will all function as territorial sources of income to their operators.

Much better to have a diverse portfolio of sustainable energy sources - than a single source. As for CHP, the Japanese Ene-FARM (SOFC) products are selling well and setting the table for western manufacturers:

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