Heat Transfer with Solar Salts

Currently, half of the world's CSP operating capacity (6.3 GWe in 2022) is with molten salt storage.

The advantages of using solar salts as heat transfer fluid and storage material lie in their environmentally friendly low carbon footprint in production, high volumetric heat capacity and high temperature operation, which increases cycle efficiency.

The CSP projects planned worldwide until 2025 - predominantly hybrid - foresee a proportion of more than 80% with molten salt storage. Due to the great potential of solar salts, it is important to consider possible applications for CSP plants in combination with hybrid projects.

Due to its large solar resource, the north of Chile offers a perfect location not only to produce solar salts, but also to install CSP plants with solar salt storage. The Cerro Dominador plant in the north of the country is the first CSP plant in Latin America, which has a large molten salt storage of 17.5 hours (46,000 tons). According to studies, it supplies 900 GWhe of electricity to the grid annually, 55% of which comes from molten salt storage.

In addition, the manufacturing company is located in northern Chile because the resources for the production of solar salts - a non-eutectic mixture of 60% sodium nitrate (NaNO3) and 40% potassium nitrate (KNO3) - are located in the same geographical location. Therefore, the carbon footprint is drastically reduced compared to other energy sources that must be imported into the national territory.  

Considering these aspects, Fraunhofer Chile can support the industry to develop new projects, offering knowledge and advice to project new CSP plants using molten salts.

FCR Services

• Simulations of molten salt CSP plants.
• Techno-economic pre-feasibility studies to evaluate the potential of molten salt CSP plants.