If successful, the monstrous energy generator could provide a cleaner alternative if renewables fail- but will it really?
It is very safe to say that the Harriet gas turbine is nothing like any other energy generator that the world has ever seen. A product of big efforts and lots and lots of money, the invention is now referred to as the Holy Grail in the power business.
We announced the construction of the gas turbine back in 2011, when many were skeptical that it would ever be realized. However, when the guys at General Electric (GE) talk, they mean business and they do anything but sell hot air (well, figuratively, because in fact this is really what they do).
Now, let’s first look at what US$1 billion in a form of a gigantic machine looks like, and what it could do.
The 9HA Harriet gas turbine burns a huge variety of natural gases, including shale gas and even liquid natural gas. It does not directly generate electricity as such, but actually produces an incredibly powerful blast of hot air, which can reach the speed of a hurricane that falls under a Category 5 in just a few seconds. The steam generator can easily provide power to 600,000 homes, running an entire 600 MW steam power plant.
The blades are made out of superalloy monocrystals, and have thermal barrier coatings, which make them resistant to temperatures as high as 2,900° F (1,600° C). Once these generate the hot air flow, it is directed via unique variable stator vanes, which are developed for supersonic jet engines. Here is a demo video, which shows how the technology works.
But this is not all. Because the Harriet turbine is bigger and more powerful than any other gas turbine ever built, there are no existing facilities or conditions that can accommodate the testing of such monster. So, in order to be able to do so, GE had to invest yet another US$185 million (on top of the US$1 billion) to build an appropriate test bed. Located in Greenville, South Carolina, it has its own gasworks, and a railway network that can transport the huge instrument.
The results from the testing will be used to improve the technology and make it fit to meet the needs of the Apparently, there are already 15 customers, who have already ordered it from the U.S, Europe and Japan.
But does Harriet really have any benefits for the environment, or is it just a demonstration of what a lot of money can build?
Patrick Chardonnal, one of two deputy directors at EDF’s production and thermal engineering division, says “The combined gas-steam thermal power plant allows us to face the lulls of electricity generated by wind and solar energy sources, when there is simply no wind or no sun.” He also says that “Substituting the old coal power plant with a gas plant not only allows us to be both much more efficient in terms of speed of production of electricity… it also helps us reduce the impact on the environment.”
The combined cycle efficiency is over 61 percent, and the turbine emits very low amount of emissions. When compared with a modern coal-fueled power plant, emissions of CO2 will be cut in half, while the levels of nitrous oxide are 10-times lower. The turbine produces a lot more electricity than any other turbine around.
OK, yes, the turbine is huge, and is definitely better than coal power plants when it comes to finding back up energy provider to the grid, when renewables do not generate enough. But imagine how many tidal turbines, or solar plants, or wind turbines could have been built with US$1.2 billion. Or why not even fund research and development of new energy storage systems, like Tesla did? If GE invested in those instead, maybe we would not need to worry about renewables under-performing. Maybe?!
Image (c) GE