Alstom's Haliade – the turbine that could change the game for US offshore wind
For a landmark pilot project to come in a year late and still be described as having gone “very smoothly” tells you something about the vagaries of fortune faced by the offshore wind sector as it strives to reach industrial maturity.
Turbine maker Alstom’s first 6MW Haliade 150 — the mightiest machine in the water, with 73.5-metre blades and a rotor sweep of almost 18,000 square metres — was supposed to be spinning at the Belwind 2 development off Belgium by the end of 2012. But weather window after weather window was slammed shut by storms roaring through the English Channel during the intervening 12 months, and the turbine was only finally assembled this past November.
A lot of people are counting on the Haliade. Despite the year-long travails suffered installing the offshore prototype, the turbine already seems to have earned a place as one of the battle-ready next-generation offshore models. An order for 240 of the turbines is cued up for a €2bn ($2.73bn) trio of EDF projects off France — Saint-Nazaire, Courseulles-sur-Mer and Fécamp — and another is in the offing for the developer’s 1GW bid for the country’s second round Tréport and Île d’Yeu/Île de Noirmoutier mega-projects.
“For our first installation offshore, we have had to manage the project in its entirety, like a full EPIC [engineering, procurement, installation and commissioning) project, not just deliver the turbine — and all in two years. It has been extremely challenging,” states Alstom vice-president for offshore wind Frederic Hendrick.
“But it was made more difficult by the fact that, with a full offshore project where you are installing 70 or 80 turbines, you will have some learnings on the first three or four that will lead you to get better and faster as you move on. But in our case, we just had one to install — all the learnings had to take place almost instantaneously.”
After the first deadline blew by Swire’s Pacific Osprey in a howling sea gale, attempts last April and July were frustratingly foiled by further high winds and waves, before the approach in the autumn by Fred Olsen Windcarrier’s Bold Tern jack-up eventually did the job — but not before it was battered about by the St Jude storm in late October.
“We just weren’t very lucky with the weather, given how small our weather windows were,” says Hendrick. “The first two sections of the [three-part] tower went up in no time — then the storm kicked off and we had to wait almost two weeks before we installed the last section. And then we had to wait again before putting up the nacelle and rotor.”
The project team did, however, make good use of the idle hours waiting for a break in the clouds, so that installation was eventually carried out “with no problems at all”.
“We spent a lot of time reviewing planning, digging deep into the details,” notes Hendrick. “When [Bold Tern] actually carried out the operation, it all went to plan.
“We accepted a challenge [to function as an EPIC contractor} and we suffered for it, but in the end we won through. And we can say [that] the biggest rotor turning at sea is ours. And do we have a better understanding of what a developer goes through on a project now? We do.”
After commissioning in 30 metres of water early this year, the Belwind demonstrator — a near “copy and paste” version of the onshore prototype tested at Alstom’s Le Carnet facility — will be studied closely as the company fine-tunes
That Alstom is expecting great things for the Haliade 150 can be seen in its ambitious plans for huge manufacturing complexes to build componentry at mass-production speed for the future roll-out.
Early last year, with money from French energy development agency ADEME, it broke ground on the first of four sprawling fabrication hubs for the Haliade, a 14-hectare plot near Saint-Nazaire harbour, where nacelle and generator factories are taking shape to supply components for 100 turbines a year.
Blades and towers are to be fabricated from 2015 some 250km away at Cherbourg, at a facility managed by partner LM Wind Power.
Alstom is throwing its considerable industrial weight behind the 6MW Haliade, with no plans on the drawing board for a 7MW model such as are being developed by Vestas, Samsung and Areva, according to Hendrick.
“The 6MW, we feel is a good compromise, in that it considers not just power output but logistics like the supply chains and installations vessels,” he notes. “When you consider the nacelle and rotor weight and the need to install them at a hub height of around 100 metres, there are very few about that can handle the job, and fewer still that can handle the 8MW designs we are seeing.
“We believe that the 6MW will be at the heart of the market for the next ten or 15 years. The game is not just to build the machines — although that is also going to be a challenge — it is also to install them and maintain them.”
The US Department of Energy and the UK Energy Technologies Institute look to share Alstom’s viewpoint: the former has backed the Haliade 150 with $4m to test the waters for a pilot project off Virginia, while the latter has an order pending for one of the machines to top its pilot PelaStar floater off southwest England.