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January 11, 2021
Paul Gipe

GE’s Haliade Offshore Wind Turbine--A Comment—or Two


Ok everyone, I’ll give in. I’ll say something about GE’s big new wind turbine that’s all the rage in the media.

Colleagues and friends occasionally force me out of isolation when some new super-duper wind invention catches the media’s eye. Typically it’s some crackpot new invention that will save the world—or so the promoter’s say. In this case it’s not some crackpot invention but a real manufacturer with potentially a real product.

I say “potentially” because I don’t follow, write about, or normally comment on offshore wind energy. This is all by way of preamble that I know nothing about offshore wind turbines.

Offshore wind is not a panacea. Sure, it’s useful. It has its niche. And there may be places where it can really make a difference, say offshore a major city with little hinterland where land-based wind turbines can’t be used. I devote a sidebar to it in my 2016 book because—invariably--someone would ask about it.

What I can say for certain is that GE knows how to write press releases and they know how to get press. Every time GE does something unusual it gets copy—and a lot of it. I am thinking of that really ugly clad tower design they hyped a few years ago that’s still standing in Tehachapi, California, marring an otherwise well-designed modern wind farm. Or that giant hemisphere they stuck on the nose of that very same experimental wind turbine and tower. Fortunately, GE had the good sense to get rid of that.

And GE needs good copy. Not so long ago there was talk of their imminent bankruptcy. In a moment of sheer genius they had bought into the coal power plant business just when everyone else was getting out. They bought Alstom’s fossil business from the French state so they could build turbine-generators for fossil-fired power plants, including dirty lignite plants. Now they’re telling France, “Ah, we may have made a mistake and we need to close part of the plant we just bought from you.” (Of course, that’s not exactly what they’re saying. They would never say that so explicitly.)

However, not all of GE’s acquisitions have been so disastrous. As part of the Alstom deal, GE got Alstom’s offshore wind business.

Now for a bit of history. In Catalonia during the 1990s there was a scrappy little cooperativa building wind turbines called Ecotecnia. They were making a name for themselves and were competing with the big boys of wind. But as the turbines grew bigger and bigger the cost of development grew beyond what the company in Barcelona could handle alone. They eventually sold out to the French (Alstom) in 2007.

What the French wanted was the turbine that Ecotecnia had under development, a direct-drive machine that eliminated the gearbox that often troubled big wind turbines. That’s the kind of turbine that Alstom could take offshore as France was pushing state-owned enterprises to get into what looked to be a lucrative new business now that nuclear was an albatross. Alstom had experience with special-purpose generators for the French nuclear navy and they hoped to parlay that into an offshore wind business with Ecotecnia’s novel turbine design.

Alstom installed the first “Haliade” machine based on this acquisition in 2012 long before GE came along in 2016.

Alstom’s Haliade machine was a giant for its day with a 150-meter diameter rotor rated at 6 MW. Because it uses a direct-drive, permanent-magnet generator, the nacelle doesn’t look like that on other wind turbines. Direct-drive generators require very large diameters—as much as 10% of the rotor diameter. This is reduced with the permanent magnets, but the diameter is still relatively large compared to conventional wind turbines and this is what gives the Haliade its unusual appearance.

A version of the Alstom design was erected in 2016 at the Danish wind test site at Østerild in the far northwest corner of the Jutland peninsula. And five of the 6 MW version were installed in the Block Island Wind Farm in 2016. (While small by European standards, Block Island was the first offshore wind farm and as far as I know still the only one in North America.)

The turbine under going testing in the Netherlands by GE Wind (offshore)—and the reason for all the media hype--is even bigger at 220 meters in diameter. That means the rotor sweeps nearly 40,000 square meters or four times more than the big Vestas V-112 that I used to illustrate rotor swept area in my 2016 book Wind Energy for the Rest of Us.

 

GE’s turbine at Rotterdam, Haliade-X, is twice the size of Alstom’s first version, Haliade-150. That’s a big jump. We don’t normally see a doubling of size in one fell swoop and it could be that GE has developed intermediate machines in the series that I don’t know about.

There are other big turbines. One is Enercon’s E-160. It too is a direct drive design but in the past Enercon has used electromagnets and not permanent magnets, which are sourced from China. Enercon also doesn’t do offshore turbines. Unfortunately, Enercon is going through some radical changes and its emphasis on sourcing content only from Europe may be changing. So who knows what’s in store. Enercon could jump in the offshore water too.

Much has been made of the power rating of GE’s Haliade-X’s at 13 MW as though this is something special. It’s the rotor that’s special not that 13 MW rating. The generator rating is comparable to other machines in that size class. Its specific power in W/m² is similar to the earlier version the Haliade-150 and not much more than the Vestas V-112 that I’ve written about. Importantly, the power rating is not outlandish. It looks like it’s within the mainstream of the industry for this application.

So yes, GE’s turbine is big, bigger than other turbines in its size class, but it’s about the same size as Siemens Gamesa’s 14-222, also a permanent-magnet, direct-drive turbine.

We don’t really know what it will cost to build and put these giants into the water and operate them. Consequently, we don’t know what the cost of electricity generated by these giant turbines will be. In the end, that’s the bottom line. And in all likelihood we’ll never know because the information will be private and confidential.

So I’d say the hype is premature, but as I noted up front, I don’t anything about these offshore turbines—so don’t ask.


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