This Island Will Charge Its Lake-Sized Batteries with Wind Power

Two hundred miles off the coast of Spain, a small island marked by a massive volcanic crater is about to become a case study for an ultramodern, zero impact society.

Over the last twelve years, engineers, researchers, and residents of El Hierro, the smallest of Spain's Canary Islands, have been building one of the world's most interesting living laboratories for sustainable off-grid living. They erected five towering wind turbines, built a huge reservoir that works as a battery, and installed three desalination plants that will let the tiny outpost harvest its drinking water from the sea. Now, the $75 million project is almost ready to be brought online.

The entire pioneering system is slated to begin its stab at modern closed-loop living at the end of June. While there are a number of solar power-reliant island communities, the press has dubbed El Hierro the first to live entirely off of the wind. Its only serious predecessor is Samso, a Danish island that's also powered almost entirely by wind power, but unlike Hierro, it's still wired up to the mainland's coal-fired grid.

Right now, El Hierro relies on diesel generators to keep the lights on for its 10,000 residents, a practice that's both costly and dirty. The new fleet of turbines will be capable of generating 11.5 megawatts of power.

That's more than enough, when the gusts are ample, to keep electricity flowing to all of its homes and shops, as wells as to its three desalination plants. So when the gales are good, water and power are teased out of the sky—but it's how El Hierro handles a lack of wind that harbors the biggest innovation.

Whenever the energy isn't being used up by the island's small grid, it's diverted to that reservoir, which is basically a giant watery battery that can store excess energy whipped up by the turbines.

As the AFP explains, "Surplus power from the wind turbines will be used to pump fresh water from a reservoir near the harbour to a larger one at volcanic crater located about 700 metres (2,300 feet) above sea level. When there is little or no wind, the water will be channeled down to the lower reservoir through turbines to generate electricity in turn."

"The lower reservoir of the pumped-storage plant being built on the island of El Hierro is lined with a high-density polyethylene geomembrane for waterproofing," a team of civil engineers who analyzed the project wrote at HydroWorld.

Pump-storage hydroelectricity, the concept behind the system, has been proven elsewhere. France, among other nations, uses excess energy from its nuclear plants to execute a similar battery concept. Belgium, meanwhile, has a much larger artificial battery island that will be able to store up to 5,000 megawatt-hours.

El Hierro's energy and environmentalist ambitions aren't new; UNESCO declared it a Biosphere Preserve in 2000, due to the island's proactive conservation efforts, and the initial plans to convert the whole island into a clean energy lab were greenlit back in 2002. It's home to a seismic monitoring system, courtesy of the National Geographic Institute, as well as an endangered, 2-foot lizard found nowhere else in the world.

Experiments like the sort El Hierro is undertaking are crucial—we need more clean energy, clearly, but as the price of solar panels and turbine blades tumble, the next great cleantech hurdle will be storing that energy for use around the clock. Smarter grids will help, but there's a reason that energy experts, futurists, and investors agree that one of most important inventions of coming years will involve a battery breakthrough. Improvements in the lithium ion batteries in our laptops and electric cars, sure—but also, more ambitious schemes. Like lake-sized moats of potential energy.

The clean energy of tomorrow will likely come from a number of inventive hybrids and technical combinations: solar panels and smart meters, wind turbines and hydro-batteries, nuclear power and floating domes. As the mercury rises, we're going to need it all, and stat.