A vertiginous outcrop with more than 500 volcanoes, El Hierro, the most westerly of the Canary Islands, is less than 12 miles (20km) wide but features elevation differences of more than 1,500 metres. Swept by strong Atlantic winds and pockmarked with volcanic craters, it has spent the past decade harnessing its natural features to create clean electricity – with the goal of being the first island to reach self-sufficiency in energy.

Now, the island is reaching new milestones. Energy generated by wind and water has enabled its 11,000 inhabitants to be completely self-sufficient in electricity for 10,000 hours since its renewables project was established.

About 50% of the island’s annual demand is now supplied by renewables. El Hierro is among the only isolated territories in the world to achieve this level of energy self-sufficiency through renewables – shutting off diesel engines and operating without external connection.

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In 2019, it had already achieved the global landmark of becoming 100% self-sufficient in electricity for nearly 25 days.

The second-smallest of the major Canary Islands, a Spanish archipelago off north-west Africa, El Hierro is now a global laboratory for renewable energy and sustainable models of farming and ocean management.

It is also a hotbed of biodiversity: more than 2,600 species have been recorded on the island, 100 of which are endemic to El Hierro. Experts hope its work on energy and habitat protection will provide a precedent for 730 million people who live on islands around the world.

On El Hierro, there is only one traffic light and no shopping malls. With no direct flights outside the archipelago, it has not been hit by the waves of mass tourism prompting protests across much of Spain.

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The calm is broken only by the wind coming off the ocean, which is harnessed by five turbines of the Gorona del Viento hydro-wind power plant.

The energy they capture supplies electricity, and the excess is used to pump water to an upper reservoir. When there is no wind, the water is released from above and runs down through the turbines to generate electricity.

“The stored water acts like a storage battery,” says María Candelaria Sánchez Galán, head of operations at Gorona del Viento. Galán left a consultancy job in Tenerife to work in El Hierro: “Who wouldn’t want to be part of a project like this, which is a global benchmark?”

Butterflies are the indicator of air quality. Everything is organic farming – it’s why they come

A devastating drought in 1948, which left the island on the brink of collapse, remains etched in the memory of the islanders. Without the money to bring water by ship, they had to plead for help from the central government in Madrid. Since then, the island has worked towards self-sufficiency.

Today, the energy needed for the three desalination plants that supply water to the island is almost entirely produced by the hydro-wind power plant. “Scientists from around the world come to study us and see how they can implement the project in their own territories,” says Galán. “We are a constantly evolving laboratory.”

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The latest figures reveal that 13,000 to 18,000 tons of CO₂ emissions have been avoided annually for the past three years. The island can now meet about half of its total electricity needs through renewables, with the goal of complete decarbonisation within 15 years. Plans are under way for a new solar power plant to boost green energy capacity.

Galán says the crucial factor is the island’s mix of renewables: “It’s what we’ve exported to the world. Our technology is not something out of the ordinary – the key is hybridisation.”

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The visible centre of El Hierro’s self-sufficiency work is the Gorona del Viento hydro-wind power plant, but the commitment to sustainability is propelled by its people.

Today, 58% of the island is a protected natural area; it was declared a Unesco world biosphere reserve in 2000 and a global geopark (to conserve sites of special geological importance) in 2015.

A flutter of monarch butterflies greets us among banana trees and pineapples, heralding the arrival of Mariela Pérez, head of the agricultural experimentation farm run by the island’s council in the Valle del Golfo.

“Do you see these butterflies? They are the best indicator of air quality. Here, everything is organic farming, and that’s why they come,” she says.

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Like many from El Hierro, she had to study elsewhere but returned to pursue organic farming. “I believe this is the way forward, and time is proving us right,” she says.

Not far from Pérez’s experimental farm, the grapevines of Carmelo Padrón thread the hillside. “This area was once covered in vineyards, but it was abandoned over time. Now, thanks to hard work, we are recovering the different varieties,” he says.

Padrón, who inherited the vineyards from his grandfather, is another young islander who went abroad – in his case to the wine regions of South Africa – then returned home. His elderly neighbours have entrusted him with their land to restore the vineyards and help preserve their legacy.

“Many of these varieties disappeared from Europe due to phylloxera,” he says, referring to the pest that devastated the French wine industry in the 19th century. “Here they have become unique.”

Thanks to the quality of the waters around El Hierro, the Sea of Calms off the south coast has become one of the best places in the world for diving and research. “We know that the sea is essential for life, and we must conserve it,” says David Pavón, an artisanal fisherman and president of the fishing association in the village of La Restinga.

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Beneath its surface, in 2011, a new underwater volcano, known as Tagoro, emerged just south of La Restinga, ejecting lava and debris that devastated marine flora and fauna. At the time, it was feared that it could be a disaster for sea life, but species are now returning.

Located just off the coast, Tagoro offered an unusually accessible study site. Eugenio Fraile, a researcher at the Spanish Institute of Oceanography, leads a multidisciplinary group studying the volcano, and says it could be another significant opportunity: “We have a hydrothermal source less than 2km from the coast that could provide geothermal energy to meet El Hierro’s demand for 20 years.”

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The Sea of Calms is also a favourite haunt of beaked whales, a species studied in these waters by Patricia Arranz, a marine biologist, working with the University of La Laguna.

“They are almost impossible to study,” she says. “They stay submerged for over two hours at a depth of 1,000 metres and only appear on the surface for about 10 minutes. They have chosen to live here because it offers them tranquility – and it gives us the chance to study them better than anywhere else on the planet.”

Arranz came to dive and fell for the island: for the past 20 years, she has lived what she calls “a love story” here, dedicating her work to protecting the species that inhabit it, and pushing for further protection, including an extended marine park.

“El Hierro is on the right track, provided we make the right decisions,” she says. “We have the choice to seize this opportunity or let it slip away, which would leave the future of these waters uncertain. Securing them would help us preserve biodiversity.”

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This article was amended on 11 December 2024. Owing to an editing error, an earlier version said that El Hierro had produced 10,000 hours of power using renewables this year; in fact this is a cumulative total of hours since the project started.

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