Power management multinational Eaton has launched a microgrid that powers its factory and campus in Wadeville, Gauteng, using second-hand lithium-ion electric car batteries for its storage component.

The batteries come from Nissan Leaf electric vehicles driven in Europe, and have about 4.5 years of operational life left. The batteries are converted and integrated into Eaton’s energy storage system xStorage, which also manages the variability of the power sources.

The 375 kVA microgrid comprises two connections to State-owned power utility Eskom’s Ekurhuleni grid, a 200 kW rooftop solar photovoltaic system, a backup generator and the storage system.

“The microgrid is a demonstration of our commitment to develop sustainable access to energy in the region and increases our resilience, provides higher levels of energy independence, supports grid stability and reduces energy costs by up to 40%,” Eaton Africa MD Seydou Kane said.

Eaton chairperson and CEO Craig Arnold, who also addressed local Eaton employees prior to the launch, spoke about the supportive role the company aimed to play in communities and on the continent.

The microgrid, which was built by the local employees (apart from the storage arrays, which were assembled in Eaton’s factory in Casablanca, Morocco), serves as a concrete case for the application of this technology in commercial and industrial use, concurred Kane.

“Microgrid technology is increasingly being considered as a solution to address energy poverty. Ageing infrastructure and grid reliability continue to be issues across the region and improving grid reliability will improve business continuity, minimise business losses and improve economic growth,” he explained.

Eaton Africa operations head Eugén Ranft emphasised the importance of the storage system, which is used to manage the significant variability of the rooftop solar and to provide power until the generator comes on line during a power interruption.

Eaton Africa senior technician Nico Archer demonstrated the use of the xStorage system at the launch, and set the parameters of the microgrid to not use more than 50 kW from the utility grid. The rooftop solar system provided between 40 kW and 180 kW during the two demonstrations and the storage array provided the difference to maintain the total load of about 280 kW on the day.

The company charges the storage system during low tariff periods, such as during the night, and during periods when it generates more power from its solar system than it requires, said Ranft.

“The storage is the heart of the system, which, through the Power Xpert power management system and architecture, provides stability and resiliency for our production plant. The Power Xpert combines hardware, software and communication elements to bring diverse power components into a unified system.”

The Wadeville facility, which employs 400 people, produces power management solutions for the industrial and commercial sectors.