Spanish island builds ‘gigantic water battery’ to increase energy security
Gran Canaria is perhaps best known for its sandy beaches, perpetual sunshine and volcanic past. But far isolated from mainland Europe, the island relies heavily on imported fossil fuels to power its growing economy – 76% of its electricity comes from burning oil.
In an effort to go carbon-free, the government has invested heavily in renewable energy to harness the island’s abundant wind and solar resources. In 2022, renewable energy sources made up 24% of the island energy mixup from just 12% in 2018. But as more renewable energy sources come online, the island has another problem: storage.
Last year the government invested €400 million in the very first energy storage system in the Canary Islands, to stabilize the grid when the wind isn’t blowing or the sun isn’t shining. However, no battery packs will be built in this project, but two existing dams will be converted into one gigantic water battery.
Salto de Chira, as the project is called ‘pumped hydropower’, will pump water from the Soria dam to the Chira dam – which is higher up – during periods of low energy demand. During periods of high energy demand, water will be discharged from Chira, through a tunnel, over a set of turbines and back to Soria. And the cycle continues.
Pumped hydropower is often referred to as a “giant water battery” because it can store and release power on demand. According to the International Energy Agencyit is still the most widely used storage technology today, accounting for more than 90% of the global energy storage capacity.
When it comes online in 2027, the Salto de Chira project is expected to generate up to 200 MW of power during times of high demand, equivalent to more than a third of the island’s needs. Last week, Spanish grid operator Red Eléctrica selected GE Energy to supply the turbines for the plant, another step forward for the plan.
According to Red Eléctrica, the project will increase the island’s share of renewable energy from 24% to 51% and save €122 million a year on imported fossil fuel. It is also expected to create more than 4,300 jobs, of which about 3,500 in Gran Canaria itself.
President of the Canary Islands, Ángel Víctor Torres, called the project a “great boost” for the archipelago’s ambitions to fully decarbonise the economy by 2040, ten years ahead of the EU’s targets.
“Energy storage is becoming one of the most important elements in the energy transition, both because of its contribution to electrification and its ability to enable better renewable energy management, which is especially important in non-interconnected systems such as the islands.” he said.
The Canary Islands have significantly stepped up their efforts to decarbonise the economy over the past five years. The largest renewable energy complex in the archipelago, consisting of eight wind farms and twelve solar power plants inaugurated in 2022 and will provide enough energy for approximately 54,000 households.
The Spanish government and the European Union have also recently announced plans to provide €20 million in funding to support the development of 65 new ones solar projects in the Canary Islands by the end of next year. The archipelago is also exploring alternatives such as wave energywith the first pilot launched in February led by Danish startup Wavepiston.
Key to the success of all these projects, says one study, are the deployment of sufficient energy storage solutions to stabilize the grid during peak demand, and the construction of sea cables to connect the islands. Pumped hydropower appears to be providing the former as the latter gains momentum with the first of many power connections now underway build to connect Tenerife and La Gomera. The connections are expected to reduce electricity costs for taxpayers and improve energy security in the archipelago.
As European countries decarbonise their energy systems, they adopt energy storage solutions to balance the intermittent supply of renewable energy and increase energy security are becoming increasingly urgent. According to the European Association for Storage of Energy (EASE), the EU will need 200 GW energy storage by the end of the decade and 600 GW by 2050.
A new industry coalition launched last week aims to promote sustainable energy storage technologies such as batteries, hydrogen and pumped hydropower to achieve these goals.
“Energy storage is key to building a future-proof, resilient and carbon-free energy system,” said EU energy chief Kadri Simson at the launch.
However, pumped hydro projects can be controversial, especially when it comes to dams on rivers that flood land to create new reservoirs and degrade ecosystems. But if marked in an article published in The conversation last year, most pumped hydropower projects do not require the construction of new dams, but the modification of existing ones, as is the case with the Gran Canaria project.
Anyway, the milestone of the IEA in 2021 Net zero in 2050 report estimates that an additional 1300 GW of hydropower is needed to meet the climate targets of the Paris Agreement. This is double the current worldwide capacity.
