The zero meridian and a plant that pumps water with wind
El Hierro has two claims that sound like brochure copy and are true: it was the world’s zero meridian for centuries, and today it is an island aiming to run on renewable energy. Both come from the same thing: being the westernmost point, and being small and mountainous.
The zero meridian, and why here
Before Greenwich was settled on, the reference meridian sat at the westernmost point of the known world. And that point, for the European geography of the time, was the western tip of El Hierro: Punta de Orchilla.
That is not local trivia, it is a consequence of position: El Hierro was literally the end of the map. Anything further west was not known to exist.
The plant that pumps water with wind
This is the project that gives the island its other fame, and the mechanism is more interesting than the headline. The problem with wind power is that the wind does not blow to order and electricity does not store well.
The solution here is wind-hydro: when there is wind and surplus electricity, it is used to pump water to a high reservoir inside a volcanic cone. When the wind drops, the water is released and drives turbines. The reservoir is the battery, and the water is how you store wind.
It works because the island has two things: constant wind and vertical drop to place one reservoir far above the other. Without the mountain there would be no system.
What you can visit and what you cannot
The plant is an industrial installation and its interior is not a freely accessible attraction. What you do see is the ensemble in the landscape, and there are interpretation centres on the island where the system is explained.
And the meridian: Punta de Orchilla can be visited, with its lighthouse, at the south-western tip. It is an exposed spot with a track for the final stretch, and its interest is exactly that: standing at the point that was the edge of the world for centuries.
Why the two stories are the same story
El Hierro is small, young, mountainous and at the far edge. That left it off the map for centuries, and that same fact is what lets it be a laboratory today: an island with gradient, wind and an electricity grid small enough to be rebuilt entirely.
Frequently asked questions
›Why was El Hierro the zero meridian?
Because before Greenwich was settled on, the reference meridian sat at the westernmost point of the known world, and for the European geography of the time that point was Punta de Orchilla, at El Hierro’s south-western tip.
›How does El Hierro store wind energy?
With a wind-hydro system: when there is surplus wind electricity, water is pumped to a high reservoir inside a volcanic cone; when the wind drops, the water is released and drives turbines. The reservoir is the battery, and it works because the island has vertical drop.
›Can you visit the plant?
It is an industrial installation and its interior is not freely accessible. You see it in the landscape, and there are interpretation centres on the island explaining the system. Punta de Orchilla, with its lighthouse, can be visited.