Batteries are holding back the microgrid energy revolution in Africa

Share on facebook
Facebook
Share on twitter
Twitter
Share on linkedin
LinkedIn
Share on reddit
Reddit
Share on email
Email
Sam Duby, is co-founder and director of research and development at SteamaCo Ltd and consults for TFE Consulting. Here he talks batteries and microgrids. Credit: SteamaCo

Batteries – the word alone causes a sinking feeling for every rural solar microgrid operator in Africa.

Why? Lead acid batteries provide energy storage for a majority of solar microgrids in rural Africa. The battery, invented in 1859 by Frenchman Gaston Planté, is most commonly used in cars where its ability to provide a surge of electricity gives the engine the large cranking force it needs to start. Almost every one of the more than 1 billion cars on the road today uses a lead acid battery. So, it is easy to see how mass production has brought the costs of this technology down over the years.

The problem for microgrid operators, however, is that batteries were simply not invented and designed to provide electricity to households. Despite being relatively cheap, lead acid batteries are not good at storing power produced on a solar microgrid. There are many reasons for this including the simple toxicity of lead. Two key disadvantages are described below.

These more ‘exotic’ technologies are currently out of reach for organisations developing microgrids in frontier markets.

Depth of discharge is the extent to which a battery is drained of its stored charge. In lead acid batteries, the deeper they are drained, the shorter their lifetime. This presents a big problem to rural microgrid operators: in order to ensure a specific amount of usable energy storage they have to install a battery bank with a much higher rated capacity than they will actually use. This allows them to obtain the intended capacity whilst only discharging the batteries by 50% (for example). This doubles the cost of installed equipment.

Other energy storage technologies do not suffer the same problems. Most flow batteries for example can be cycled indefinitely and can be taken to a 100% depth of discharge. Likewise, some of the newer battery chemistries coming to market including those based on saltwater electrolytes claim 100% discharge with no negative effects.

Lead acid batteries have a relatively high energy density when compared to technologies like flow batteries (but not when compared to newer technologies like lithium ion), which made them popular with early car manufacturers for whom weight was obviously a concern. Flow batteries have actually been around longer and have been successfully used for years to power signal systems on railways. The issue with them is that they are quite heavy for the power they contain. However, for a static application such as a microgrid, energy density is less of a concern and non-toxic flow batteries could be a good fit.

These are not insurmountable problems however, and storage technologies already exist that do not have the same disadvantages. I have mentioned flow batteries and wet cells that use novel electrolytes, but there are others out there, not least of all super capacitors, which are starting to edge towards commercialisation.

The rural microgrid market is still in its early stages and much more needs to be done across financing, regulations, technology innovation and new business models. TFE Consulting have engaged with a wide range of microgrid installers, multilateral organisations and rural electrification agencies in East Africa that have mentioned better storage technology as a key factor in the acceleration of microgrids. The problem of course is accessibility. These more ‘exotic’ technologies are currently out of reach for organisations developing microgrids in frontier markets. Better energy storage is a relatively low hanging fruit and actors across sectors – donors, development banks, entrepreneurs – need to consider ways to solve this core technology challenge in order for microgrids to scale as a viable energy access solution.

Credit: SteamaCo

Read Next

September 28, 2021
The Australian Renewable Energy Agency (ARENA) has launched an AU$50 million (US$36 million) programme to support microgrid pilot projects and improve the reliability of electricity supply across regional Australia.
September 13, 2021
Louisiana communities hit by Hurricane Ida are benefiting from newly deployed solar installations thanks to a collaborative effort by local installer PosiGen Solar and non-profit organisation the Footprint Project.
July 15, 2021
A round-up of the latest stories from the US solar market, featuring proposals to support long-duration energy storage, patent successes from LONGi and the completion of a microgrid at Pittsburgh International Airport that features 20MW of solar.
December 1, 2020
A round-up of the latest news in solar project development, as juwi hits 3GW installed PV milestone, Greencells makes further progress in the Netherlands and plans for a Cambodian solar-plus-storage microgrid are announced.
October 26, 2020
A round-up of the latest news in solar project development worldwide, featuring news from EDF Renewables, Hive Energy, Sterling and Wilson and Disneyland Paris, of all places.
October 21, 2020
Travel restrictions imposed by countries in response to the coronavirus pandemic have contribution to a slowdown in investment in rural electrification projects. Thomas Hillig examines the extent of the investment freeze and possible solutions to get capital flowing into much needed projects again

Subscribe to Newsletter

Upcoming Events

Solar Media Events
December 1, 2021
Solar Media Events
February 1, 2022
London, UK
Solar Media Events
February 23, 2022
London, UK
Solar Media Events
March 23, 2022
Austin, Texas, USA
Solar Media Events
March 29, 2022
Lisbon, Portugal