Warta says his opinion was merely strengthened after a visit to the renewable energies exhibition at the Hannover Industry Trade Fair in April. "Qualified people from at least six wind companies could give no satisfactory technical answer to the problem of the intermittency of wind energy generation," he claims. "What's the point of installing wind power equivalent to 30% of energy demand, if backup power generating plant equivalent to 100% of energy demand still has to be built to ensure security of supply?"
His lack of understanding of the fundamentals of modern power supply structures is fortunately not typical. Unlike GEC-Alsthom, a Franco-German conglomerate, other power station construction companies appear to be keeping up with market development. Nonetheless, their main strategy seems to be to continue supplying existing wind turbine manufacturers with components rather than striking out on their own or buying into an established wind company. Siemens Kraftwerk Union is not alone when it explains that it simply lacks know-how for full scale wind turbine manufacture. Instead, it is aiming to set an industry standard for a 750 kW direct current generator system.
Like Siemens, Asea Brown Boveri (ABB), is more interested in supplying components than building wind turbines, though it was deeply involved in the installation of a turnkey 6 MW wind farm of Austrian Floda machines on the Golan Heights in Israel in November 1993. But after that experience its wind department has been all but disbanded. "I would describe ABB's response to the developing wind energy business as active market-watching," says Hanning Kempe from the company's power generation division in Zurich. "Research is being conducted on the feasibility of wind energy projects and we are considering possible options for a future engagement," he says. "However, current wind activities are restricted to the production of components such as generators, with which we have a 30% market share, transformers, medium voltage switchgear and control systems. Research is mainly concentrated on generators."
Deutsche Babcock, in Oberhausen, sings the same melody, but with a different theme. Unlike Siemens, it has a subsidiary, Balcke-Dürr in Ratingen, perfectly capable of building wind turbines. "The company manufactures energy plant and also cooling towers which have large fans and the aerodynamic know-how associated with these fans would lend itself quite easily to the construction of wind turbines," says Günther Holtmeyer from Deutsche Babcock's new technology department. The Deutsche Babcock company has therefore regularly examined whether it should start up a wind turbine section. However, the conclusion each time has been that this would only harm the business dealings of two other Deutsche Babcock subsidiaries already supplying the wind industry with components -- Flender, which supplies gearboxes, and Loher, which produces generators. These two firms are already linked in the Flender ATB Loher Group.
At the moment, both Flender and Loher are considered neutral suppliers. But if their sister company began wind turbine production, Flender and Loher customers could fear that know-how associated with production of their products would flow back to Balcke-Dürr, now a competitor. "Assuming we get a good price for our turbine components, it is probably more to our advantage to stay as a supplier than start production of the whole machine," sums up Holtmeyer.
Loher already feels it is playing a significant role in wind. The Ruhstorf-based division of the Flender ATB-Loher Group is this summer delivering its first generator for megawatt scale wind turbines, a 1.2 MW asynchronous generator for a prototype wind turbine being developed by German company Autoflug. Loher has been supplying generators to the wind business for over ten years, initially for the MAN Aeroman machines. The company's Gotthard Christoph says: " We can supply turbine generators from 7.5 kW up to 6000 kW with 50 or 60 Hz, although no-one has yet asked for a 6 MW machine." In July, though, the company received an order for 12, 1 MW generators from a wind company. "Now we can really start talking about series production," says Christoph. The Flender ATB-Loher Group employs 3200 people and clocked up sales in 1994 of DEM 400 million.
Taking a lead
Siemens KWU, in contrast, is not content to simply follow and service the market. It wants to be in a position to determine what is built. The company is currently developing an innovative generator and control system for a 750 kW wind turbine without a gearbox which the company wants to become the "industry standard." Explaining the KWU strategy, spokesman Wolfgang Breyer says: "We have chosen a rated capacity of 750 kW because we think this is where the main market will lie. We don't want to supply the whole market but we want to be leaders in this particular market segment. We want our 750 kW to become a standard. If a turbine manufacturer comes to us and says we want a 500 kW generator, our answer will be, sorry we don't do it. Just like Henry Ford, our philosophy is you can have any generator system you want as long as it is a 750 kW."
According to Breyer the direct current generator "produces a beautiful sinus curve, not the jagged current fed into the grid by most turbines, much to the irritation of the utilities." The output of the variable speed turbine is converted into 50Hz alternating current using an Insulated Gated Bipolar Transistor, usually referred to as the IGBT. Breyer argues that wind turbines without gearboxes will be cheaper and cost benefits are there for the taking. Philosophising over the dominance of asynchronous generators in the wind business, Breyer says it is only now that electronics have been developed sufficiently to cope with controlling a direct current generator.
Siemens' prototype 750 kW generator will be supplied for a Nordtank turbine due to be installed in Baden Wuerttemberg before the end of 1995. But the company has no intention of supply exclusively to one wind firm in what it describes as a "pronounced growth market." Again, it feels the best strategy is to concentrate on what it is best at. "We are specialised in the supply of electrotechnology equipment and have no experience in the construction of, say, blades or towers," underlines Breyer. Through a daughter company, Antrieb, Schall und Insulation (ASI), Siemens currently supplies asynchronous generators for wind turbines with rated capacities of 100 kW to 1 MW. "Siemens is one of the five largest generator suppliers in the world and we have a market share of around 20% of wind turbine component supplies," adds Breyer.
So far the company has not supplied generators above 1 MW, aside from the 3 MW generator for the long defunct Growian experiment in multi megawatt scale wind technology. But KWU sees a bright future. "The market has now developed beyond the 500 kW mark and we can clearly see a long term market in the 500 kW to 1 MW sector. We decided to take the middle road and plumped for 750 kW," says Breyer.