Designing power systems is a complex business, requiring an understanding of myriad factors, from technology to economics and social science. No two situations are identical, and the more options that are available to system designer, the more closely the solutions can meet the needs individual communities.

Access to electricity is accepted as a societal good, facilitating an improved quality of life directly; though lighting, refrigeration, entertainment and communications, and enables access to information, improved healthcare and many other benefits. Sustainable energy is one of the UN sustainable development goals and an enabling technology for many others. Yet there are still over a billion humans in the world with no electricity.

There are two standard approaches to providing electricity for those with no access. The first is to extend an existing national grid. This approach benefits from years of experience around the world, as well as economies of scale, but the further from existing infrastructure or the more spread out the loads become, the more costly grid extension is. There is also significant investment of both resources and time required to extend or build a national grid, potentially leaving people without power for many years to come, even if the grid will eventually reach them.

The second approach is to build smaller, self-sufficient energy systems, for single houses or communities, known as mini-grids. These systems can be rolled out to remote locations much more quickly and, with dropping costs of solar power, are becoming increasingly affordable. Many systems are designed for the short term, and as demand grows locally, they often struggle to keep up. Mini grids also benefit less from the effect of diversity of supply and demand, requiring more installed capacity per person than a large, national system.

Both approaches are suitable in some situations, but the more options that are available, the easier it becomes to deliver the goal of low cost, sustainable and reliable energy for all.

My research is investigating the value of a third approach, supplementary to the two outlined. This approach involves connecting together existing mini grids, like those proposed in the second approach above, to share generation, demand and storage. This could allow a grid with a hydro generator to provide backup to its neighbour, who could in turn sell back their excess solar energy on a sunny day.

As well as the ability to share energy, this approach can allow system design to be more flexible. Small mini grids can initially be constructed to meet the basic energy needs for lighting and phone charging, and as and when demand grows, systems can be interconnected and upgraded. Finally, if the national grid reaches the now interconnected grids, there will be a ready constructed distribution network in place.

The technology is just one dimension of the solution. Sharing energy and fostering community engagement and ownership will require new and innovative market mechanisms, education and clear technical standards.

Providing reliable, sustainable and cost effective energy for the whole world is an enormous challenge, but offers an opportunity to address both human development and environmental concerns. By connecting together energy systems from the bottom up, we can put individuals and communities at the centre of the future power system.