South Africa’s largest power supplier, Eskom, opened a battery-testing and demonstration facility in Rosherville, Johannesburg, in early June. Here it will compare different battery technologies with a view to installing 2,000MW of back-up power for the country’s national grid.

Two battery chemistries — lithium-ion and sodium nickel chloride — are already being tested but the facility, believed to be the first of its kind in South Africa, is capable of testing five chemistries simultaneously.

“The facility is not limited in terms of the technologies and if we were presented with interesting business cases for lead-acid cells we would carefully consider them,” a spokesperson for Eskom told BESB.

“This is not the first time we have looked at storage but it is the first time we have tested cells at a relatively large scale with a view to developing bulk grid storage options for Eskom going forward.

“At this stage battery storage is one of the best solutions in South Africa but we are aware of CAES, flywheels and the like, and monitor them all closely to see what is possible and available.”

Eskom operates 23 power stations with a total nominal capacity of 42,000MW, of which 35,700 is sourced from coal-fired stations.

The country’s Integrated Resource Plan of 2010 called for 18,000MW of renewable energy generation capacity to be added, which would require up to 2,000MW of additional energy storage within the existing grid, according to Barry MacColl, Eskom general manager for research, testing and development.

The capacity expansion programme should be completed in 2021.

Eskom intends to look at using energy storage to cope with peaks in demand and using solar power at night, as well as investigating the role of energy storage in deferring spending on grid transmission and distribution infrastructure.

Eskom is traditionally the main supplier of generation, transmission and distribution capacity to industrial, mining, commercial, agricultural and residential customers.