The technlogy and the challenges

Lack of money in Ecotècnia's early beginnings lies behind the co-operative's strong market position today, says boss Antoni Martínez. "Right from the beginning, in order to survive, we had to get the technology right every time in order to generate financing," he explains.

Ecotècnia sees the development of its Tarifa 150 kW prototype in 1989 as the big turning point. Two years later, Germany's Fraunhofer-Institut für Solare Energisysteme (ISE) classed the machines as "the best wind turbine in Europe," in terms of production compared with rotor size. The report was based on a comparison of the 4100 wind turbines then operating in Europe. By 1993, Ecotècnia had 50 of these machines up and running in Tarifa.

Since then, Ecotècnia has turned out a range of machines from 225 kW to 750 kW, the latter making up the bulk of the company's 338 MW installed capacity total. And now it is installing a 1.25 MW prototype in Navarra to be followed shortly by a 1.6 MW turbine in Tarifa. Martínez says that while the growth in rated capacity of the Ecotècnia design requires a series of technological adaptations, the principal remains the same.

"The key to our design is simplicity, which is often the hardest thing to achieve," he says. This is the main reason for having stuck with fixed pitch and stall regulated technology from its first machines right up to the 1.25 MW turbine. But there is a limit to blade length in a fixed pitch system. This is why Ecotècnia has incorporated variable pitch and variable speed technologies in its 1.6 MW turbine, he says.

Nevertheless the gearbox design and overall transmission system introduced from 1996 in Ecotècnia's 640 kW machine, will remain. Here the main concern is to maximise the power transmission from rotor to generator while minimising the stress on the gearbox. Ecotècnia turbines isolate load cycles and rotor oscillation by supporting the hub of a fixed main frame within the nacelle.

Ecotècnia has also launched its own centralised wind farm control system called Argos. It has also been working on a revamped version of a prototype Internet-linked plant operation and management (O&M) system called NetFarms.

Research into improved methods of integrating wind plant within the grid is on-going. This involves creating ways in which the distribution companies can control the capacity factor of wind plant in accordance with the load on its network. Wind prediction techniques are part of the methodology. Ecotècnia is currently developing these projects at a wind plant in Galicia.

Another main focus of Ecotècnia's research and development division is to find ways of making megawatt machines easier to install in the mountainous terrain that harbours many of Spain's wind plant. The high tonnage cranes needed to lift such generators are difficult to get up mountains. The nacelle contents of Ecotècnia's megawatt range machines have been designed as three separate modules which can be transported, lifted and assembled at the top of the tower.

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