Atacama PSH: EIA Submitted, a Key Milestone for our 3,600 MWh of Storage project in Chile

HYVITY and our Chilean partner Susterra have reached a major milestone in the development of the Atacama pumped storage hydropower project with the filing of its Environmental Impact Assessment (EIA). With 3,600 MWh of storage capacity with up to 450 MW power, Atacama aims to turn surplus daytime solar generation into competitive, dispatchable electricity available at night.

A major development milestone

Located in the municipality of Caldera in Chile’s Atacama Region, the project is being developed to support renewable energy integration and meet the growing decarbonisation needs of mining and industry.

The EIA filing marks a key step in the permitting process, enabling environmental assessment and engagement with the authorities and stakeholders ahead of the approvals required for construction. The project represents an estimated capital expenditure of USD 775 million, excluding financing costs.

Storing daytime solar energy for use at night

Northern Chile has an exceptional solar resource. Yet abundant daytime generation can exceed the system’s ability to absorb it, leading to renewable energy curtailment, while demand remains strong after sunset. Atacama is designed to address this mismatch at scale.

The project will operate as a closed-loop system with two reservoirs. Surplus renewable electricity will pump water into the upper reservoir during the day. When electricity is needed, the water will flow back through turbines to the lower reservoir, releasing the stored energy.

With 3,600 MWh of storage capacity with up to 450 MW power, Atacama will be able to deliver up to eight hours of generation at full output. This duration will allow substantial volumes of solar energy to be shifted into the night, reducing curtailment and extending the value of renewable generation beyond daylight hours.

Combining abundant solar generation with long-duration storage creates a strong competitive advantage. Atacama aims to provide highly competitive stored energy and, together with renewable generation and an appropriate supply portfolio, support green electricity offerings available 24 hours a day, seven days a week. This directly addresses industrial customers’ need for reliable supply, predictable costs and lower emissions.

An advantageous location for project development

Atacama benefits from an ecosystem that brings together access to water, electricity infrastructure and nearby demand. Agreements with existing desalination facilities provide a basis for supplying the water required to fill the reservoirs and compensate for operating losses. The planned grid connection via the Cardones substation will link the project to the regional electricity system.

Nearby mining and industrial consumers represent a natural market for stable, dispatchable green electricity. This combination of infrastructure and demand strengthens the project’s positioning as a large-scale storage solution for northern Chile.

Supporting grid stability and energy sovereignty

Beyond shifting energy from day to night, Atacama is designed to provide dispatchable capacity, inertia and grid support services. Its rotating hydroelectric equipment can help maintain system stability as the share of solar and wind generation increases.

Based on a proven technology and designed to operate for many decades, pumped storage offers a durable contribution to Chile’s energy sovereignty. By making better use of domestic renewable resources and strengthening security of supply, Atacama will support industrial competitiveness and the transition to a lower-carbon electricity system.

With this milestone, HYVITY and Susterra continue to pursue a shared ambition: to make long-duration energy storage a driver of industrial competitiveness and decarbonisation, supporting Chile’s energy transition.