First kilowatts for Haliade 150

Alstom has started the certification tests of its offshore wind turbine 

The Alstom offshore wind turbine has just produced its first kilowatts at the Carnet site, near Saint-Nazaire, in the Loire-Atlantique (France). In preparation for its certification, the Haliade 150 is undergoing a series of tests on land, before the placing of a second turbine in the North Sea, off the Belgian coast, end 2012 for a second campaign of offshore tests. With 6 MW and its 150 m rotor, the Haliade 150 is the largest offshore wind turbine in the world.

Onshore and offshore product certification tests
The tests permit validation for the various simulations (stress, temperature, life span) that went into the design process of the Haliade 150 making it possible to refine and perfect its operating capacity. The tests will be conducted over a period of around 18 months.

Analysis of the turbines power curve which determines its capacity to produce electricity efficiently   according to the wind is central to this certification procedure. A measuring  tower, permitting  precise  measurement of the meteorological conditions under which the tests are conducted, has been installed next to the wind turbine and a hundred sensors placed on different parts of the machine.

During the pre-validation phase in progress, the wind turbine produces its first low-wattage kilowatts (0.5 MW - 1/12th of its rated power) to test the blade rotation system and the transfer of the electricity produced by the generator to the high-wattage network via the electric sub-station.

This phase will be followed by a validation phase to gradually step up the wind turbines electricity production from 0.5 MW to 6 MW fully in line with the technical specifications defined for the turbine. The objective of this crucial phase is to guarantee a minimum operating time of 280 hours without stopping. A series of measurements are taken of the wind, vibrations, the temperature of the magnets and the air-gap cooling system . To be validated, the wind turbine has to be tested three times at 20m/s wind points during 10 minutes each time.

The Carnet site, located on the banks of the Loire estuary, was chosen for its geological characteristics very close to the submarine environment in which the wind turbines will be installed. The 25 metre sub-structure (known as the jacket) was installed on pillars driven more than 30 metres into the sea bed on which the 75 metre high tower was then gradually mounted. In all, the nacelle rises more than 100 metres above ground. The wind turbine and its support structure have a total combined weight of 1,500 tons. 
All the electrical equipment installed in the tower (converters, transformer, low-voltage electricity network, computer systems and calculators) will undergo advanced validation tests. The generator will be subjected to tests that measure the operating temperature, vibrations, current and voltage. Then, the turbines different mechanical components will be subjected to vibrations, stresses (notably for the blades) and reaction times. This phase of the validation tests will be completed by analysis of the turbines overall performance and its piloting software parameters.

The offshore tests will permit testing of aspects of maintenance and connection under real operating conditions. Alstom and Belwind NV, the Belgian leader in offshore wind turbine energy production, have signed an agreement to install the Haliade 150 in the Bligh Bank farm located 45 km off the Belgian coast, near the port of Ostend where it will be operated by Belwind under concession. The Haliade 150 will be connected to the electricity station of the first phase of the field. This agreement is valid for 10 years and renewable for a further 5 years.

Leading edge technology for the largest wind turbine
Each of these next generation wind turbines will be able to supply the equivalent of the electricity consumption of about 5,000 households.

To meet the severe challenges posed by the marine environment, Alstom has developed a 6MW wind turbine which is simple, robust and efficient, to improve the competitiveness of offshore wind power. Simple, this wind turbine will function without a gear box (by direct drive) and is fitted with a permanent magnet alternator, to reduce operating and maintenance costs. Robust, the Haliade 150 is fitted with Alstom PURE TORQUER technology which protects the alternator by diverting unwanted stresses from the wind to the turbines tower, thereby optimizing performance. Lastly, the Haliade 150 offers greater efficiency with its 150 metre rotor (the 73.50 metre blades are the longest in the world) ensuring an improved load factor.

A first wind turbine built like a series turbine
The first nacelle for the Haliade 150 was assembled at Saint-Nazaire, in a temporary pre-series workshop which will produce about 40 units over the next three years. The second unit is currently being assembled here. About 40 Alstom engineers and operators are employed on these assembly operations.

The assembly begins by the turbines central block which forms the interface between the tower and the nacelle. This block contains the direction drive system (which includes a direction bearing) that permits adjustment of the nacelles position in relation to the tower, allowing the turbines nacelle and blades to be instantly re-directed to capture the wind. To facilitate maintenance operations, the central block is equipped with a helipad so that response personnel can be winched up into a helicopter.

At the same time, the intermediate block is fitted to the permanent magnet generator which will be driven directly by the blades rotation to produce electricity. These two blocks - central and intermediate - are then fitted together to receive the turbine rotor to which the 3 blades are also in turn fitted. This 150 metre diameter rotor is connected to directly drive the generator rotor. The nacelle represent a total weight of 360 tons .

The pre-series workshop at Saint-Nazaire will play an important role in the future production process of the offshore wind turbines. A certain number of rules and procedures will be applied right from the first units and subsequently implemented for commercial production. Pre-series production is planned for 2013 and series production will begin in 2014.

A new industrial sector for French and European markets
Alstom will be creating four factories in France dedicated to the production of components for offshore wind turbines and their assembly in the port zones of Saint-Nazaire (Loire-Atlantique) for nacelles and alternators, and Cherbourg (Manche) for blades (in partnership with LM Wind Power) and towers.  With capacity for 100 units per year each, these four factories will be operational in 2014 (for the nacelles and alternators) and in 2015 (for the towers and blades). An engineering and R&D centre employing 200 people and dedicated to offshore wind power, will also be established in the Pays de la Loire region.

These French sites will be the first Alstom sites in the world dedicated entirely to offshore wind power and will permit the creation of 5,000 permanent qualified jobs, including 1,000 direct jobs. They will initially manufacture the 240 wind turbines that will be installed in the French wind farms of the North Atlantic from 2016 onwards. Alstom is the exclusive supplier of the consortium led by EDF Energies which won 3 of the 4 fields attributed by the French government in April. This consortium includes Dong Energy, the Danish energy specialist and world leader in offshore wind turbines, as well as the developers Nass & Wind and wpd Offshore.

This industrial plan will also serve the needs of the European market: with planned capacity of 40 GW by 2025, the European offshore wind turbine market is mainly concentrated in North Europe (United Kingdom and Germany).   

Press contacts
Christine Rahard, Isabelle Tourancheau - Tel +33 1 41 49 32 95 /39 95
christine.rahard@chq.alstom.com, isabelle.tourancheau@chq.alstom.com