CO2 Battery – Proconics brings 18

CO2 Battery – Proconics brings 18-hour energy storage technology to South Africa

Long-duration storage could solve renewable energy’s night-time gap as recapitalisation of older wind and solar projects gathers pace.

ENGINEERING group Proconics has partnered with Italy’s Energy Dome to provide the latter’s CO2 system, which offers energy storage for up to 18 hours, making it a viable solution for businesses that require renewable electricity around the clock.

Though the South African renewable energy market is maturing, with solar and wind power projects coming online regularly, the inability to supply power at night looms large over the sector.

Discovery Green recently cautioned that businesses must be careful when agreeing to power contracts that lock them into a renewable tariff plan which does not take into account their nighttime supply needs.

Discovery Green, a division of the Discovery Group that offers electricity trading and energy consulting services, said businesses might be attracted to the cheaper renewable energy tariffs they can get during the day, but not realise that battery storage can only supply a maximum of four hours.

For its part, the Energy Dome battery provides energy storage for up to 18 hours. During the day, it uses excess (usually renewable) electricity to compress and liquefy CO2 from a dome at ambient temperatures. Then at night, the now liquid CO2 is evaporated and expanded through a turbine to generate electricity. The CO2 is sent back to the dome to start the next charging cycle.

The Energy Dome battery can be configured to store energy for use by its customers. In Australia, for example, it provided a 20 MW/200 MWh CO2 battery that can last for 10 hours. It has also installed a similar system for Google in Sardinia.

Proconics CEO and founder Melvin Jones said there was already a lot of excitement about the technology in South Africa. “We are looking to bring Energy Dome’s technology into the country. There is quite a lot of interest from the Independent Power Producers (IPPs), Eskom and Sasol.”

Jones said he saw the potential in using the Energy Dome battery not only for new renewable energy projects but also for older ones.

Projects that were launched in South Africa’s Renewable Energy Independent Power Producer Procurement Programme (REIPPPP) Bid Window 1, 2 and 3 – which were launched over 10 years ago – are being recapitalised.

Aside from putting in more modern and efficient equipment, Jones said there was an opportunity to expand the scope of these projects by adding battery capacity.

“Recapitalisation of those projects is definitely happening. There’s a lot of work being done to retrofit renewable energy projects to become hybrid.”

Jones said the Energy Dome battery could be the solution to the energy dilemma, where excess renewable power is produced during the day but no power is produced at night.

“If you just look at supply and demand, it’s going to mean that long-term power in the middle of the day is going to tend towards being free. But power at the peaks in the morning and the evening, and even through the night, is going to become expensive. Unless we can shift it from when it’s produced to when it’s dispatched.”

Proconics is well placed to introduce this technology, given its background as an engineering, procurement and construction (EPC) project company that specialises in improving and extending the life of factories.

The group was spun out of Sasol in 1995, and initially was a service provider to large industrial companies. As the energy sector started to democratise, it expanded its offering to cater for the needs of new entrants into the sector.