El Hierro: the island where renewables are a treasure

El Hierro: the island where renewables are a treasure

In the Atlantic Ocean, more than 100 km off the shores of Morocco, there's an island that's unique in the world: El Hierro.


In the Atlantic Ocean, more than 100 km off the shores of Morocco, there's an island that's unique in the world: El Hierro. This small plot of volcanic land covering 224 km2 - less than a third the size of New York City - ranges from the 1500-metre high Malpaso peak to the 300-metre deep sea beds of the La Restinga marine reserve.

El Hierro is the smallest and wildest island of the Canaries, declared a biosphere reserve by UNESCO. At night visitors enjoy the clearest sky in Europe. But this is not what makes the island unique.

"El Hierro is the first fully sustainable island in the world, made completely self-sufficient thanks to renewable energy"

Where the water meets the wind

It only takes just over one day to traverse the entire length and breadth of the island, a journey on which the traveller never loses sight of the Atlantic that surrounds the island and is accompanied by the wind that blows over its slopes.

The far northern town of Tamaduste is less than a nine-hour walk from the southern tip of La Restinga, where ferries from Tenerife dock.

Travellers who make this journey along the coast after less than two hours will reach the small port of Estaca, where there's an artificial lake. Looking inland, they will spot five wind turbines in the distance. These are a modest signal of the secret that makes El Hierro unique: the Gorona del Viento hydro/wind plant.


Building the future together

With the shore of Africa not visible beyond the horizon and just over 10,000 inhabitants, El Hierro has always had to find ways to power everyday life on the island. Grids cannot cross the Ocean, but electricity for daily life had to get there somehow.

Since 1971, the island has been equipped with a diesel-powered plant. But a plant run by fuel - albeit indispensable and an necessary solution at the time - clashed with the earthly paradise otherwise offered by the Canaries.


"Turning El Hierro into a fully-renewable and energy self-sufficient island was achieved through collaboration between public administration, private enterprise and academic research"

The municipality of El Hierro, together with the Instituto Tecnológico de Canarias (ITC) and Endesa, the Enel company that is a leader in the Spanish electricity market, in 2007 established Gorona del viento, a company whose specific purpose was the construction of a plant that would enable the island to be powered exclusively by means of clean energy.


The crown of wind

Farmers living on El Hierro have always built low walls to protect their cultivations from the continuous gusts of wind from the ocean. Shaped like a half-circle, they look like crowns made of stone, and that's why they are called goronas del viento.

Those who built the plant looked back to this ancient custom and used the same name for their project, though they turned the force of wind into an ally capable of protecting the island and its natural resources.


“We have conceived a hydro/wind plant that combines wind and water, integrating both sources into a cutting-edge renewable facility.”

On the eastern slopes of El Hierro, five wind turbines of 2.3 MW each are combined with an 11.3 MW hydropower system, converted from a non-active volcanic caldera, to generate green energy.

An artificial lake close to the small Estaca port acts as a water reservoir and, due to the energy conveyed by the wind turbines, serves as a pumping station that is useful to balancing the electricity grid.


A fully renewable island

Since the hydro/wind plant was put into service in June 2014, the biodiesel facility is increasingly seldom used, only for emergencies, and also this summer the whole of El Hierro was powered for full days with energy that is entirely renewable.

Thanks to this environmentally friendly system, we can provide clean energy to the whole island, saving 18,700 tonnes of CO2 and reducing the use of oil for the fuel-powered plant by 40,000 barrels each year.