Developed through the Innovation Lab, finally there is an electric mill for use on mini-grids with the potential to compete with diesel-powered mills. In an article for the NextBillion Series “New Frontiers in Renewable Energy”, CrossBoundry argue that this mill prototype might prove a game-changer for both millers and mini-grid developers across the continent.

Grain mills are at the heart of the energy-agricultural nexus in Africa. Using mini-grid electricity would not only save money for the millers, but it would also give them a more reliable energy source whilst eliminating the air pollutants produced by burning diesel. There are also advantages for the  mini-grid companies: bringing grain mills onto their grids would significantly increase electricity sales and improve the economics for mini-grids. However, despite the fact that mini-grid developers have tried to source a competitive solar-powered electric mill, diesel mills still dominate the rural off-grid market. No existing solar-powered electric mill can match them on both cost and performance.

A 2020 study by Energy 4 Impact and the Efficiency for Access Coalition Co-Secretariat, CLASP, found that solar mills cost twice as much as diesel mills. The monthly energy spend to power an electric mill is also twice that for a diesel mill. On performance, diesel mills have also set the standard for throughput: the amount of grain milled per hour. 

According to the study, 95% of millers prefer solar PV to diesel as an energy source. Millers are even willing to pay more for an electric mill provided it can compete on operating cost and performance. Yet such a mill is not currently available on the market. The economics of mini-grids will only change if a competitive mill for solar mini-grids can be developed and scaled in terms of production.

The Mini-Grid Innovation Lab has been working with developers on this problem over the last 12 months. Established in 2018 by CrossBoundary and The Rockefeller Foundation alongside Energy 4 Impact, and more recently supported by the Foreign, Commonwealth and Development Office (FCDO) and Shell Foundation, the Lab works with developers to identify and test innovative prototypes that improve the business model. The partners have since jointly developed an electric mill for use on mini-grids that promises to outperform diesel. Results from lab and field tests show that the prototype mills are four times more efficient than the diesel mills on the market.

For the Lab, proof of success is always based on longer-term performance tests on the ground. Therefore ten prototype mills have been deployed at mini-grid sites across Tanzania. If the initial results appear promising, the Lab will work with global appliance suppliers, local manufacturers and developers to distribute electric mills at mini-grid sites across the continent.

This is a summary of an article written by Jane Dougherty, associate, Erika Lovin, Innovation Lab Lead and Gabriel Davies, Head of Energy Access at Cross Boundary. The article was published in April 2020 on NextBillion. Read the full article here.