In late November no information was available on the cause of the failures in the KW Tarifa wind plant on November 11 and 17, although eye witness reports say the blades in both cases snapped off at the root. Kenetech has promised further information as soon its engineers turn in their report.
The incidents at the 30 MW wind farm caused the company to turn off several of the 300 kW turbines sited close to a main road, presumably because of the potential safety hazard from flying blades. Kenetech says its foremost concern is safety: for the surrounding community, for its employees and for the wind plant.
The failures have come as the windy winter season gets underway. In the first failure, one of the turbines lost a single blade in gusty high winds, whereas the second time round two blades came off a second malfunctioning KVS-33 in light winds. The breaking point was reported as being identical in both cases, stemming from a crack an estimated 50 centimetres from the hub.
According to Kenetech's Bud Grebey, the company's technicians plan to thoroughly examine each turbine before connecting it back to the grid on a one-by-one basis. "Individual wind turbines will only be operated as they are deemed safe," he says.
Asked if the problems at KW Tarifa are related to the "floppy ears" blade failures which occurred back in 1994 (Windpower Monthly, December 1994), Grebey says it is still premature to judge what has gone wrong and that any evaluation now would be pure conjecture.
Meanwhile in Seville, capital of the region where Tarifa is situated, parliamentary deputies of the Conservative PP opposition party have requested an investigation into the possible safety implications. "Although in both cases nobody was hurt or damage sustained, it is of the utmost urgency that a thorough investigation be carried out to avoid new incidents in the future, especially since the wind farm is situated near the main road," says PP's Jorge Ramos Aznar.
KW Tarifa has only recently been inaugurated, although it has been up and running since June. The project was built by Kenetech and sold to a group of companies, although the American wind power company retains a small stake in it.