AES Andes, a utility operating in South America owned by AES Corporation, has revealed plans to convert 560MW of thermal power generation into a molten salt-based energy storage plant in Chile.
The firm has submitted documents to the website of Chile’s national Environmental Impact Assessment (SEIA) agency outlining the plans.
So-called Project Alba, it would see AES Andes turn its Angamos coal-fired power plant in north Chile – Central Termoeléctrica Angamos (CTA) – into an energy storage unit with 560MW of power output.
The energy storage unit would use a system of salts heated to between 310-560°C, which would then enter a water/salt heat exchanger to release the stored thermal energy, generating steam to move the turbogenerator. The electricity generated could then be injected into the country’s National Electric System.
Its Environmental Impact Statement said the project would need a total investment of US$450 million.
It mentions a ‘cycle’ to heat the salt of 10 hours but it is not clear if this means the system would also have a discharge duration of 10 hours. That would mean a total energy storage capacity of 5,600MWh or 5.6GWh.
The plant would need 700MW to heat the salts to the desired temperature, which would come from renewable energies via the nearby Angamos substation.
The company said the project would contribute to the decarbonisation of Chile’s energy system, by reducing emissions from the plant by 50%.
AES Corporation owns over 98% of the shares of AES Andes and together with Siemens owns a majority of the shares of the largest battery energy storage system integrator Fluence. Fluence typically deploys all of AES’ projects in the Americas but has not ventured outside of battery storage so its potential role in this project is not clear. It could provide its renewable energy optimisation software platform.
Companies which have developed energy storage solutions using salt include Malta Inc and SaltX.
Local outlets have reported that the German Agency for International Cooperation GIZ and Siemens Energy are supporting the project.
AES Andes is currently working on a 112MW/560MWh battery storage project in Chile paired with 253MW of renewable generation from solar PV and wind. Fluence will be supplying battery storage equipment and integration services to that one.
Parent company AES Corporation signed a cooperation agreement with the country’s government during the 2021 COP26 climate talks representing an investment of around US$400 million. One interesting related fact is that AES deployed the world’s first megawatt-scale lithium-ion battery energy storage system (BESS) at a coal power plant in Chile, back in the late 2000s.
The AES Andes filing comes as Chile’s government considers passing major legislation incentivising the deployment of energy storage, as reported by this site earlier this month.
Read the Spanish-language Statement from AES Andes in full here.
