If there is one factor that holds those living in emerging markets back from realising their full potential, it is the lack of reliable access to electricity. Why has it been so difficult for developing nations to achieve energy equality, and what can be done to remedy the problem?

Fortunately, new technological advances in the use of adaptive mini-grids, such as those now being demonstrated in Rwanda, offer a happy ending to a seemingly intractable problem.

Populations in emerging markets can be categorised into three groups: those with regular access to a reliable supply of electricity; those with access to intermittent or unreliable electrical power; and those who cannot access electricity at all.

The effectiveness of extending conventional power grids to bring reliable power to more of the population is often hindered by low customer density and consumption, poor access to finance, and low reliability and high cost of centralised energy production. Indeed, a 2022 World Bank report estimated that by 2030 mini-grids could be the most competitive means for serving up to 490mn people.

However, even the latest mini-grid technology platforms don’t allow project developers to simultaneously keep a high utilisation factor (ie assets are fully utilised to serve the load) and maintain reliability in an environment imbued in change and uncertainty. This is mainly because the current generation of mini-grids, which inherited their centralised architecture from backup systems used in developed countries, are built around a single point of supply which forms the grid and from where power has to be delivered to customers in a limited geographic region to prevent voltage quality deterioration.

These cannot practically exchange power with other autonomous systems since their voltage and frequency control targets would either conflict, or perform poorly, when one of them is set to grid-following mode.

Next generation mini-grids
Now, thanks to new digital technologies designed to work with renewable power sources, the next generation of autonomous power systems will drastically improve in their ability to cope with, and take advantage of, change.

Mini-grids make economic sense when sharing energy resources can be cheaper to provide reliable power to a group of customers, compared to each of them running their own power supply system, or than extending the main grid from a distant location. Situations where customers are close together and consumption is high, local energy resources exist, and the public grid is not close by are where mini-grids make most sense – providing cheaper power than either isolated systems or grid extensions and higher resilience in the event of external disturbances.

However, the factors that influence the break-even point, such as concentration of customers, consumption per customer, local availability of energy resources, proximity and quality of the public grid etc, are generally unknown and subject to change. For example, consumption growth never materialises, the local utility brings power lines prematurely, or an economic opportunity appears that would require higher power devices.

Despite massive improvements in the cost and quality of building blocks such as lithium batteries, photovoltaic (PV) panels and inverters, the approach keeps following a guess-optimise-build pattern, all the way from government-level electrification planning to the deployment of individual systems.

The alternative to the current approach, which builds according to what one estimates will happen in the future, is to grow energy systems adaptively as scenarios unfold. The latter is not easy though; you need to be able to add capacity in small increments and anywhere in the network, then you have to find a way to operate tightly sized mini-grids reliably. Last, there has to be a way to make decisions about when and where to add capacity.

New platforms now being built address all these hurdles with a combination of hardware, local controls and cloud-based software – that was simply not possible previously.

Maximise investment returns
Tightly sized mini-grids inherently maximise investment returns through higher utilisation factors. For example, say you deploy a PV system capable of serving 1 MWh of load per day, and your customers are only taking 0.3 MWh – you are still paying for the cost of financing the whole panel, but less than a third of the investment gets turned into revenue.

Besides efficiency in terms of added capacity, adaptive grids can do it geographically in pretty much any direction that makes sense. PV, batteries and other distributed energy resources (DERs) can be distributed anywhere in the network, improving voltage profiles and reducing distribution losses. This is done without compromising reliability. In contrast with grid-forming/grid-following architectures, adaptive grids are fully homogenous in the sense that the failure of any DER doesn’t compromise the stability of the system.

Furthermore, they can merge with other adaptive grids and with the main grid, taking advantage of energy sharing or of cheaper, low-reliability power. If the main grid is around, and even if reliability is low, why not go back and forth between islanded and grid-connected modes?

The first pioneering demonstration of an adaptive and decentralised mini-grid, installed and now operative in Gakagati villages, Rwanda, is showing what will be possible. Mini-grids can be truly transformative to the lives of millions and at last allow emerging market populations to realise their true potential.

The views and opinions expressed in this article are strictly those of the author only and are not necessarily given or endorsed by or on behalf of the Energy Institute.