Gran Canaria's Chira Dam: A Pumped Hydro Battery Built Backwards 2026

Gran Canaria's Chira dam, a key part of the island's water supply, became the center of a pumped hydro project that critics say was built backwards. In 2022, Red Eléctrica began constructing a cavern pumped-storage plant between Chira and Soria reservoirs. The plan was to use the plant as a giant battery, pumping water uphill when electricity is cheap and releasing it downhill to generate power when demand peaks. But the project ran into a fundamental problem: the water needed to fill the system wasn't readily available.

The issue came to light in March 2026 when Antonio Morales, president of the Gran Canaria Island Council, announced that after recent storms, the island's water reserves had multiplied by 17, with 35 dams full and irrigation secured for five years. He called it a "historic situation." Yet of the seven dams managed by the Council, only six were full. The seventh, Chira, was at 51% capacity. That was still significant, but it highlighted a deeper problem: the Council needed to reach the bottom of the reservoir, and the pumped hydro project had started construction before ensuring water access.

Why Gran Canaria Relies on Reservoirs

Gran Canaria has 172 dams across just 1,560 square kilometers, making it one of the most dam-dense places in the world. This isn't a whim; most were built to capture the little rainfall that occurs and direct it to agriculture. Chira, started in 1941 and completed in 1964, is the island's second-largest reservoir with a capacity of 5.64 million cubic meters. For decades, it has simply stored water.

The pumped hydro idea seemed clever: use excess renewable energy to pump water from Soria to Chira, then release it back down through turbines when needed. But the project overlooked a critical detail: the water in Chira is already allocated for irrigation and consumption. Diverting it for energy storage could disrupt those uses, especially during droughts.

The Technical and Environmental Hurdles

Building a pumped hydro plant in a cavern between two reservoirs is complex. It requires tunneling, massive turbines, and a reliable water source. In Gran Canaria's case, the water source is variable. The island experiences prolonged droughts, and even with recent storms, reservoir levels fluctuate. The project's viability depends on having enough water to cycle between the two reservoirs without depleting Chira's reserves.

Moreover, the environmental impact of constructing underground caverns and pipelines in a protected area could be significant. Local groups have raised concerns about habitat disruption and the visual impact of new infrastructure. The project also faces regulatory hurdles, as it must comply with water use regulations and environmental assessments.

What This Means for Energy Storage

Pumped hydro is the world's largest form of energy storage, accounting for over 90% of global storage capacity. It's essential for integrating variable renewables like wind and solar. However, projects must be carefully planned to avoid conflicts with water resources. Gran Canaria's experience underscores the need for integrated planning that considers water availability, environmental impacts, and community needs. Context on how this played out before sits in Gran Canaria's Chira Dam: A Pumped Hydro Battery Built Backwards.

As islands transition to renewable energy, storage becomes critical. But solutions must be tailored to local conditions. In Gran Canaria, that might mean exploring alternative storage technologies or redesigning the pumped hydro project to use seawater or treated wastewater instead of freshwater. The background to this story is set out in Energy Utilities: latest articles. A related thread runs through LA's 96 Million Shade Balls: Water Savings and Hidden Costs.

Key Takeaways

• Gran Canaria's Chira dam was chosen for a pumped hydro project without securing sufficient water, leading to operational challenges.
• The island's high dam density reflects its reliance on water storage for agriculture and consumption.
• Pumped hydro projects must account for local water scarcity and competing water uses.
• Environmental and regulatory hurdles can delay or derail such projects.
• Integrated planning is essential for successful renewable energy storage.

Comparing Reservoir Uses

What to Watch Next

Gran Canaria's government must decide whether to proceed with the pumped hydro project, modify it, or abandon it. The outcome will depend on water availability, environmental reviews, and economic feasibility. Meanwhile, the island continues to rely on its reservoirs for water security, especially as climate change brings more erratic rainfall. Earlier coverage in Spain Water Reserves Keep Falling: Time to Prepare for Drought shows how the argument developed. A closer look at the same subject appears in China's Gravity Battery: A Giant Storage System in Rudong.

The Chira case offers a cautionary tale for other regions considering pumped hydro: start with water, not with construction. As the world races to build energy storage, learning from such mistakes is crucial. Anyone following the wider picture can start with Tibi Dam: Europe's Oldest Reservoir Built for Philip II in 1580. The same theme surfaces in Snowy Hydro 2.0 Executives Get $751,925 in Bonuses Despite Cost, which takes a different angle.