El Hierro is the easternmost of Spain’s Canary Islands, 750 miles from the Spanish mainland.  The island itself has no energy resources beyond wind and water.  There is now a plan to make the island wholly energy independent by linking wind and hydro-power together to provide a constant and reliable supply of electricity.

A Spanish Island’s Quest to Be the Greenest Place on Earth

Five windmills on the northeastern end of the island will power a pumping station that, when the wind is blowing, will drive water 2,300 feet uphill, from a small, 5 million-cubic-foot (150,000-cu-m) reservoir down by the shore to a larger, 19 million-cubic-foot (550,000-cu-m) reservoir snuggled into one of the island’s volcanic craters. When the wind abates, water from the top depository will be released, along 1.8 miles (3 km) of mostly camouflaged pipes, into the bottom one, and the pressure of that falling water will drive six hydraulic turbines. In other words, El Hierro will combine the two resources in which it abounds to deliver a continuous supply of electricity, no matter the weather. “If we don’t want to depend on fossil fuel, we have to have steady input and output,” says Gonzalo Piernavieja, director of research and development for the Technological Institute of the Canaries, which designed the plant. “And the only way to do that is through massive storage. In this case, we’re using nature’s gifts, wind and sea water, for storage.”

The plant is expected to produce 48 GW/h (gigawatt hours), enabling El Hierro to conserve some 6,000 tons of diesel per year, and to meet 100% of its energy needs by 2015. And by that time, the island will be well into its next sustainability projects. One of them, already underway, is a plan convert all 4,500 of El Hierro’s cars to electric; the same municipal company, Gorona del Viento, that is building the new hydro-electric station will supply car batteries powered by excess energy from the plant. “The whole system will be integrated,” says Javier Morales, El Hierro’s councilman for sustainability. “It’s beyond green. When the power plant and the car system interact, it will be like galaxies colliding.”