El Hierro becomes first isolated territory powered 100% by renewables

El Hierro, the smallest and most westerly of the Canary Islands, has become the first isolated territory in the world to meet all its energy needs using renewables. For four hours from 12 noon on Sunday August 9, the Gorona del Viento wind-hydro power station generated all the electricity for the tiny island of 10,000 inhabitants using clean energy – the culmination of a project that began 30 years ago.

“It’s amazing!” says Gonzalo Piernavieja, head of research, development and innovation at the Canaries Technological Institute, one of the entities taking part in the local council-led project, along with power company Endesa and the Canary Islands regional government.

In the coming decades the system will save El Hierro around €80 million that would have been spent on 6,000 tons of diesel each year

The Gorona del Viento wind-hydro power station has been hooked up to five wind-powered generators that together are able to produce the 35 GW/h the island requires. In the coming decades the system will save El Hierro around €80 million that would have been spent on 6,000 tons of diesel each year, as well as reducing carbon emissions by around 20,000 tons annually.

The project, which has cost €82 million, has been hailed as a major achievement around the world. It represents the first time that wind and hydro power have been combined. Once the wind farm has generated enough energy to meet the island’s needs, the excess is fed into the power station’s pumps, which raise water from a reservoir located at sea level to a height of 700 meters. On days when the wind is not sufficient to provide the required energy, the hydraulic installation comes into play. The water is channeled back down to the lower reservoir, moving the turbines that produce the electricity needed for the island.

Around 80 percent of El Hierro’s energy is already produced via renewables, but that figure can rise to 100 percent for certain periods, sometimes of up to a week, says Piernavieja. “There are Pacific islands with fewer than 1,000 inhabitants, as well as some African communities, that have also been able to meet all their energy needs using renewables, but nothing compares to what we have achieved on El Hierro, both in terms of the number of people we are supplying, as well as the fact that our system is not connected to the outside world, and is housed entirely on the island.”

Belén Allende, the head of the local council on El Hierro, says she is proud of the achievement: “This is a day that will be remembered by the rest of the world.” She hopes that El Hierro’s know-how will be used by other islands. “There are around 17 million people living on islands in Europe, and 600 million across the planet,” she says, adding that the plan now is for El Hierro to become a kind of open-air laboratory for other environmental initiatives. Representatives from Japan, Taiwan and the Faroe Islands have recently visited El Hierro to look at how to adapt the technology to their own needs.