Decentralized solar-plus-storage would fire sub-Saharan Africa

Sub-Saharan African countries should seriously take into account decentralized solar-plus-storage to improve access to electricity, according to a recent study from UC Berkeley, published in Nature Energy.

The authors of the research claim decentralized solar systems relying on storage may not only be suitable in remote areas without grid connection, but also in locations that are linked to power grids. The researchers point out national grids in the region have serious financial and structural problems, and are unable to expand due to the difficulty of attracting investment for new power infrastructure.

“Customers that currently have grid access might choose to stop using the grid, especially in regions where grid costs are high or reliability is low, and this could make it difficult for utilities to continue with their current business model,” the report's authors explain.

To create more sustainable and cheaper energy systems, say the scientists, Sub-Saharan countries will have to push the adoption of decentralized solar-plus-storage, although the price of storage technologies is not permitting the deployment of generators able to provide power cheaper than large, state-run grids.

Storage system costs hamper deployment

The researchers developed a model based on 10 years of solar data from NASA which is said to prove most Sub-Saharan regions can obtain reliable power from solar-plus-storage 95% of the time, at a price of around $0.40 per kWh.

“Though that cost is high relative to current grid costs, their model indicates that with aggressive but plausible future cost declines in decentralized system costs – largely in batteries – these costs would drop to levels competitive with the grid in many parts of the continent in less than a decade,” they state.

The report's authors, who have also analyzed how costs change with each “9” of reliability — for example from 90% to 99%, or 99% to 99.9% – have provided an aggressive cost decline scenario in which a “reliability premium” may be under $0.04 per kWh per 9 of reliability.

“These low reliability premiums suggest that customers would have incredible autonomy to choose the quality of their electricity service, and this could be an important piece of the puzzle in expanding electricity access across populations with different reliability needs,” said research coordinator, Duncan Callaway.

That decentralized solar-plus-storage will be the most likely solution for Sub-Saharan Africa’s future energy landscape appears to be confirmed not only by the increasing number of mini-grid and large-scale standalone projects, but also by the declining number of announcements of grid improvements across the region.