Curved water tank with a dark coating and intense green water, located next to a cliff. At the top, a road is visible, and in the background, hills with wind turbines and the ocean under a clear sky.
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The electric currency of El Hierro: history, myth, and energy

In recent years, a surprising story has circulated on the internet: in the 1940s, during the post-war period, the people of El Hierro supposedly created an “electric currency,” paper bonds backed by the electricity of a small local power station, which were used to pay in stores and for daily wages. It's an attractive tale, but how much truth is there in it?

A set of wind turbines located on arid hills by the ocean. The large white turbines rise above the reddish dry land, connected by dirt paths, while the blue sea stretches out on the horizon under a clear sky.

What we know (and what we don't)

So far, we have not found any documentary sources — archives, press from the time, or economic history studies — that confirm the existence of this electric currency in El Hierro. It does not appear in reference works on the history of electricity in the Canary Islands. The most prudent approach is to consider it a modern legend, perhaps born from mixing two realities: the scarcity of money in the post-war period, when local vouchers and bonds circulated in many places in Spain, and the current fame of El Hierro as a pioneering island in energy.

If you have documents, photographs, or family memories that talk about these bonds, we would love to hear about them and update this article.

An island with its own electrical grid

What is real is the energy challenge of El Hierro. Like the other islands, it has an isolated electrical system, without connection to other islands or the mainland. For decades, almost all its electricity came from a diesel engine power station, with the fuel costs and emissions that this entails.

Gorona del Viento: the power plant that changed history

In 2014, it was inaugurated Gorona del Viento, a unique hydro-wind power station in the world. It works like this:

  • Five wind turbines, with a total power of 11.5 MW, generate electricity when the wind blows.
  • The excess energy is used to pump water from a lower reservoir, of about 150,000 m³, to another upper reservoir, of about 380,000 m³, located at 655 meters above sea level.
  • When the wind is lacking, the water flows back down and drives hydraulic turbines, which return the energy to the grid.
  • The old diesel plant remains as backup.

The system does not yet cover 100% of the demand throughout the year, but it has achieved historical milestones: in 2018 the island ran solely on renewable energy for 18 consecutive days, and in some months, such as July 2024, it has managed to cover around 77% of the demand.

A story that connects past and future

With or without electric currency, El Hierro demonstrates that a small island can be a laboratory of solutions: from fog water harvesting in the Garoé tree to a power plant that turns wind into water and water into light.

If you want to feel the pulse of the island, you can see it live with our webcams of El Hierro.

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