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Grid storage could aid African electrification

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The total installed electricity generating capacity in 48 sub-Sahara African countries is roughly the equivalent of Spain, according to The World Bank. Frighteningly, as much as a quarter of that meagre supply is offline at any given time, due to poor maintenance and ageing infrastructure.

Regardless, one in five sub-Sahara Africans simply do not have access to electricity and fewer than 40% of African countries will achieve universal access to electricity by 2050.

One of the challenges is the cost to build and then maintain infrastructure.

But grid storage solutions can help to overcome that challenge. That insight emerged at the XON and NEC Summit recently held in Limpopo Province, which included Magnus Coetzee, MD of XON Alternative Energy.

Grid infrastructure must be built to handle peak loads. That means overhead and underground cables must be thick enough to withstand low amp but exceptional voltages to distribute electricity from generating source to point of use. Over a distance of that between Johannesburg and Cape Town, for example, losses to resistance can be as high as 30%.

Nonetheless, consider the cost of a two-, three-, or four-inch copper core with the requisite infrastructure strong enough to withstand nature and other forces spanning the entire length of the country. Maintaining that infrastructure is also a full-time job and the bigger it is to handle peak loads – representing just a fraction of the time the infrastructure stands – the more expensive it is to maintain.

“If you could build infrastructure a quarter of the size you could slash your build and maintenance costs over many decades,” says Coetzee.

Grid storage consists of banks of specifically suited lithium-ion batteries built into containers with sophisticated management systems. The alternating current- (AC) coupled batteries are charged by the grid energy source during off-peak times and discharged, to feed grid-connected households and businesses, during peak load periods. This is the same theory that is applied to pumped hydro storage. A recent example is the Ingula Pumped storage scheme being executed by Eskom in South Africa to handle peak demand. If you look at the power, useful capacity and current published cost, a grid storage solution from NEC Energy Solutions would come at par in unit cost (US$/kWh) with the added advantages of (1) being easily scalable, (2) can be deployed locally where the demand power is needed, (3) does not have environmental impact involved with pumped hydro, and (4) can be operable within six to nine months from the time the contract agreement is concluded.

“This one change distributes electricity supply to the regional level, which results in a far more resilient grid infrastructure as well as cutting costs to build and maintain,” says Coetzee. “It could prove the significant differentiator in bringing energy supply to a greater number of African households.”

These solutions are already proven elsewhere around the world. In South America, for example, these containerised units are supplying enormous quantities of energy to the grid for different applications; the same model is used in the centre of London. In fact, 150MW of power is already being supplied globally using this model.

“There’s no reason why African utilities cannot use the same technology to drive widespread economic growth as emerging markets, and specifically Africa, increasingly represent the force behind global economic progress,” says Coetzee.