ABB: Optimizing Power Conversion and Transport System the Key (Interview)

During the EWEA 2015 in Paris, Offshore WIND met with Alfredo Parres, Head of Wind Sector Initative at ABB Group, whose main role within ABB is to integrate different wind-related activities under the same umbrella.

This in turn is part of an overall strategy aimed at optimal positioning and to grow the company within the wind sector, by looking at current and future markets and customer demands, it was said during the interview.

Major interlinked business and technology focus areas include wind turbine and wind farm grid compatibility, control systems, and power storage. Parres said: “In the latter area we recently acquired an Australian company specialised in flywheel technology, which is highly suitable for coping with short-term grid fluctuations. However, ABB does not manufacture the batteries of power storage systems in-house, and the application itself concentrates at embedding these in power lines instead of at turbine level. We further actively participate in ongoing discussions on the upcoming ENTSO-E grid code demands for 2016 and beyond.”

He added that the Double Fed Induction Generators or DFIG’s, also manufactured by ABB in various power ratings, are currently subject of hot industry debate. This focuses on facts and perceptions of their capability to meet ENTSO-E and even more stringent future grid code demands. “DFIG’s are still widely used and their market share in main market China is for instance 75 – 80%, whereas several leading suppliers in Europe and the US apply DFIG’s too. We closely follow these developments, and are at the same time highly flexible in meeting changing industry demands if these occur.”

During September 2010, ABB presented the outcomes of a comprehensive study on the future of wind turbine drive systems at the international Husum wind industry fair. One main conclusion was that medium-speed drivetrains with permanent magnet generator (PMG) operating at medium voltage level would become the future technology winner for large-size turbines, offering the highest reliability and lowest LCOE.

However, this was before the rare earth’s price hike and rocketing magnet price levels at the end of 2010 and the first half of 2011. When asked if and/or how these technology preferences might have changed from todays perspective, Parres said: “My overall feeling is that the majority of onshore turbine suppliers for the moment decided at sticking to their current drivetrain design choices. This means, for those applying high-speed geared systems, a further utilizing of remaining reserves and stretching technology system boundaries. However, I am also convinced that this is in essence a delayed response in the final switch to the medium-speed geared. ”

Further elaborating on the ‘optimal’ drivetrain topic, he said that medium-speed has established itself faster in the offshore market, including two 8MW turbine models. In addition, rare earth’s price levels have come down substantially since 2011. According to Parres, it is also a fact that medium-speed systems roughly require only one quarter of these strategic metals compared to direct drive: “We are often approached by turbine and wind farm end users for specific advice on gaining advanced insight on drivetrain solutions best suiting their demands. LCOE should in all circumstances remain the key decision driver, but it is also of great importance to consider specific design-related and reliability-enhancing aspects, critical components and serviceability & maintainability issues.”

He added that ABB in these specific circumstances acts as an independent adviser to end users in getting feedback on drive technology performance in the field. But the collected data also helps ABB to further improve on designs, especially with regard to maintainability aspects.

Finally, a number of suppliers has announced or already markets turbines with 25-year or even 30-year design life. Parres considers such developments as a grand opportunity and a key instrument in further driving down LCOE: “30-year lifetime does not automatically mean that all components should last that same period. The wind industry, including ABB, still has a lot to learn on optimal strategies on getting there, both in emerging and established markets and the best solutions are not automatically similar everywhere.”

Interview brought to you by Eize de Vries