The publicly controlled developer, Gorona de Viento, now expects the combined wind and hydro power plant, with a capacity of 11.5MW and 11.3MW respectively, to power up by end-2011. They combined resource will cover 80% of the island's electrical power consumption.
Gorona de Viento is a consortium. 60% is controlled by the local government of El Hierro. The remainder belongs to both the local utility Unelco-Endesa, with 30%, and the ITC with 10%.
The €60 million project forms part of a wider and longer-term goal to make the tourist island self reliant for 100% of its primary energy needs using only renewables. The 278km2 island, with a population of 11,000 people, has a peak demand of 7MW and an annual demand in 2009 of 41.53GWh.
The five Enercon 2.3MW wind turbines will both feed the island's isolated grid and, when production exceeds demand, pump water to a natural reservoir formed by the crater of Hierro island's extinct volcano. The 1500m-drop to the lower reservoir will drive the hydro turbines, covering periods of lower winds and higher electricity demand.
The hybrid will substitute the long-since amortised 13.3MW Llanos Blancos power plant, whose nine 1.47MW diesel generators currently provide most of the island's electricity (private stand alone diesel generators and photovoltaic modules provide the rest).
Apart from providing a model for other islands and isolated grids, the El Hierro project will also offer value experience on balancing wind and hydro for large, meshed continental grids, according to Gonzalo Piernavieja of the Canaries Technology Institute (ITC), which instigated the project in 1997.
The final contract, a €6.5million control system deal, has gone to Spanish electrical engineering firm Elecnor. The company had already won contracts to supply and install the project's transformers, hydro turbines and 6MW pumping system.