Sirius Exploration has released details of the latest report conducted on its behalf, exploring the feasibility of using compressed CO2 to create energy storage facilities for the production of electricity.

Compressed air based electricity generator systems have already been built in the US and Germany, but Sirius Exploration Plc, the mining and exploration company focused on North America and Australia, is exploring the possibility of using compressed carbon dioxide (CO2) within underground salt caverns, to create energy storage facilities for the production of electricity.

Directors of Sirius have announced the findings of a technical report conducted by UniQuest Limited of Queensland, Australia, for CO2 Energy Storage Pty - Sirius’ 100% wholly owned subsidiary.

In previous releases and presentations, Sirius has described the use of Compressed Air Energy Storage (“CAES”) as a means of storing electricity. This can be used for peak load demand and can also be used as an environmentally friendly method of storing wind generated electricity for use when power is actually required as distinct, as opposed to when the wind is blowing.

The research described in the new report however, investigates a scenario whereby CO2 will be used in place of compressed air.

Initially, the CO2 would be sequestered and compressed into a salt cavern. There is then a closed loop process whereby the CO2 is bled off into storage caverns to provide power, and recompressed to provide energy storage.

In this process the CO2 is not only removed from the atmosphere, but it is then used to provide ongoing power generation and storage.

Richard Poulden, Chairman of Sirius, commented, “We are greatly encouraged by the findings of this first report as it confirms from a technical perspective the possibility of being able to use CO2 - as opposed to Compressed Air for which the technical case has already been proven – as a medium for storing energy and subsequently driving electricity generating turbines.”

“Through this approach, we are potentially looking at a technology that can transform harmful emissions into clean energy and provide an important support mechanism to utility and energy companies.”

“Through our subsidiary, CO2 Energy Storage, we will continue our R&D into this area and begin building the economic model for Carbon Dioxide Energy Storage (CDES) facilities for potential use, where appropriate, on our properties. As such, this activity is part of our strategy to build a range of complementary solutions for extending the commercial life of our salt properties once the mining phase has been completed.”

The modelling was done using MATLAB programming. The research team analysed two scenarios using a cavern 50 metres in diameter, 100 metres deep and located at 1500 metres below ground.

In the first scenario, a power recovery ratio of 69% was calculated with an overall energy efficiency ratio of 18.6%, due to requirements of cooling for the compressors and heating for the turbines.

In a supplemental scenario, a power recovery ratio of 65% was identified with an overall energy efficiency of 12.1%.

Whilst the power recovery ratio was slightly lower in the second scenario, it only required two additional caverns to allow the discharged gas to be bled into after the compressed CO2 from the main storage cavern had been re-released through the turbine to generate electricity. In the first scenario, multiple caverns would be required.

The report also confirms that it is logical that the technology would qualify for Renewable Energy Certificates.