How a small Spanish island became a renewable energy pioneer

Islands confront some of the most difficult energy challenges. Their size and remoteness means they pay extremely high energy costs for often unreliable and dirty energy. Yet many islands are blessed with large amounts of sun, wind and water, making renewable energy a promising solution. One small island off the coast of Africa has embraced these resources, most notably through an innovative hybrid hydro-wind system.

The smallest and most remote of Spain's Canary Islands, El Hierro (pop. 10,700) is a land of lava-sculpted rocks, cliff-lined shores and crystal-clear waters. It is a diver's paradise, yet remains relatively untouched by tourism. In the early 1980s, the island took its first environmental stance, opting for a development model based on respect for the island's heritage and conserving its natural resources. "At the time, these guidelines seemed to be in contradiction to the social and economic dynamics of the Canary Islands that were seeking to attract mass tourism built on a foundation of a spectacular real estate business," the president of the El Hierro Island Council, Tomas Padrón, said in a presentation to UNESCO. "It now gives us great satisfaction to be able to say that we have seen that the road chosen by the people of El Hierro was the right one and we are proud of living in harmony with a natural habitat that has remained largely unaffected by the hand of man."

In 1997, El Hierro was the first in the Canary Islands to adopt a sustainable development plan to protect its environmental and cultural richness, prompting UNESCO to declare the entire island a biosphere reserve in 2000. Yet the island still was importing and burning 6,000 tonnes of diesel per year, emitting 18,700 tonnes of carbon dioxide. Twenty percent of the electrical energy consumed ran three desalination plants to generate water for drinking and irrigation. So a lack of energy on El Hierro not only meant not being able to turn on the lights; it also meant suffering from a scarcity of water and thus food.

The government of El Hierro realized conservation wasn't enough; it needed to take things a step further and become a 100 percent energy-self-sufficient island. Fortunately, Padrón was not only president of El Hierro's local government, but also knew a bit about electricity because he worked at the island's electric company. With some research and education, Padrón and the new Department for Alternative Energy Research convinced people of the viability of a hydro-wind system.

A public-private partnership was formed between the Island Council, the Spanish energy company Endesa and the Canary Islands Technological Institute to develop the project, Gorona del Viento.

A wind revolution

El Hierro now has five wind turbines with a combined installed capacity of 11.5 megawatts soon to provide the majority of the electricity for the island. When wind production exceeds demand, excess energy will pump water from a reservoir at the bottom of a volcanic cone to another reservoir at the top of the volcano 700 meters above sea level. The upper reservoir stores more than 132 million gallons of water. The stored water acts as a battery. When demand rises and there is not enough wind power, the water will be released to four hydroelectric turbines with a total capacity of 11 MW. 

The entire project, expected to come online this year, is projected to generate three times the island's basic energy needs for residents, farming cooperatives, fruit and fish canneries, and the 60,000 tourists who visit every year. Any excess electricity will be used to desalinate water at the island's three desalination plants, delivering almost 3 million gallons of water a day, enough for drinking water and to cover part of the irrigation needs.

While energy storage via pumped hydro is not new — plants already exist in numerous countries around the world — El Hierro's is the first major plant not to use conventionally generated electricity. The hydro-wind plant had to pass rigorous environmental criteria (Spanish) to make sure it didn't negatively affect the ecosystem of the area. The project developers had to remove and replant Macronesian heaths (native shrubland habitat), replant protective embankments and protect a certain variety of cypress.

Besides reliable electricity, more fresh water and improved agricultural opportunities, the Gorona del Viento partnership expects to earn over $5 million a year in electricity sales, and save almost $2.5 million a year in diesel imports. Because the whole project cost about $93 million, half of which was funded by a European Union government grant, project partners will recoup their investment relatively quickly. Once the system is paid off, the revenue from the project, aside from the amount used for system maintenance, will be put back into the local economy.

Next steps

El Hierro's next goal is to replace all 4,500 of El Hierro's cars with electric vehicles. According to Javier Morales, El Hierro's councilman for sustainability, if they sell electricity at the same price as gas, they can recoup the necessary $90 million in infrastructure costs in 10 years. The EV batteries will be charged with excess energy from the hydro-wind plant. "The whole system will be integrated," Morales told Time magazine. "It's beyond green. When the power plant and the car system interact, it will be like galaxies colliding."

The island also has embarked on a solar thermal program to replace electric water heaters and a PV rooftop program. Future plans include having all the island's agricultural cooperatives convert their fields to organic production (they already have signed on to the plan), with each farm having a biodigester that converts waste into methane for fuel and fertilizer.

"At first, it was simply an issue of becoming more self-sufficient," Padrón told Time. "We were completely dependent on outside deliveries and could be cut off at a moment's notice. But then with the global energy crisis, and climate change, and everything else that's happened, we've realized it has a lot more value."

El Hierro's hydro-wind plant does have a lot more value. It is serving as a role model for renewable energy projects in other isolated communities. Similar projects (PDF) are under consideration in the Greek islands of Icaria and Crete, and Portugal's Madeira. "The 'El Hierro 100 percent Renewable Energies' Project will make our island the first in Europe to be supplied with renewable energies," Padrón said in his presentation to UNESCO, "turning it into a worldwide benchmark in implementing energy self-sufficiency and autonomy systems based on clean energy sources."

This story first appeared at Rocky Mountain Institute's RMI Outlet blog. Lead image of El Hierro by Karol Kozlowski via Shutterstock