Sirius takes advantage of storage solution

Enviromine

Sirius Exploration plc, a potash exploration company with development projects in Australia and the US, plans to exploit the salt voids left after extraction for CO₂ and compressed air storage.

“The caverns left after in-situ salt mining are perfect for storing CO₂, hydrocarbons, or as an electricity store,” deputy chairman Richard Poulden told MEM.

The company is currently investigating options to use the cavers, which will range from 0.5km to 2km deep, for compressed air energy storage (CAES).

Energy produced from sources such as wind or solar power is converted in to compressed air and stored underground until it is required at which point the air is decompressed and released into the local or national grid as electricity.

“Electricity needs storage,” Mr Poulden said. “Electricity that is produced and is not stored is wasted, and renewable energy sources need storage more than conventional sources as the supply is more variable”.

The company estimates that one cavern can store up to 400MW of energy, to be released when it is needed.

Sirius said that initiatives are underway at its Dakota project in the US with EPRI, Basin Electric and Schlumberger to assess the potential for CAES, and applications have also been submitted for state assistance.

Alternatively, the company plans to use the caverns for CO₂ sequestration, which can also be used for electricity generation by compressing and decompressing the CO₂ through a series of chambers in a closed system.

Schlumberger is currently preparing a study assessing CO₂ storage.

“The question is, are there any problems with the chemistry,” Mr Poulden said, adding that this was not a long-term solution as there was potential for the CO₂ to eventually leak from the caverns.

Sirius anticipates it will take 2-3 years to prepare the caverns for storage and have all its partners ready.