How Low-Carbon Microgrids Are Making Factories More Flexible

The rise of solar power is driving the creation of local, decentralised energy networks, running separately from the grid.

These so-called microgrids could power a single building or a whole village and can enable neighbours to sell each other electricity, and bring energy to remote areas. They could also help secure factories against power cuts, says Fabrice Roudet, head of the energy storage business at Eaton.

The benefits of microgrids include continuity of service, and a reduced environmental footprint. Because they can easily be linked to sources of renewable energy, they offer factories a way of cutting their emissions, and when combined with batteries can be a cleaner source of back-up power than polluting diesel generators.

There are some issues, such as space, but “you can overcome that issue by adding an installation right next to the building,” says Roudet. He says microgrids will be most useful in developing economies, where the normal power supply can be unreliable – he points to an installation that Eaton recently carried out in South Africa as evidence of that.

This installation used solar panels, batteries and a diesel generator. “In case of outage from the grid we use batteries, and if it’s longer than expected we use diesel generators,” explains Roudet. This project cut consumption from the grid by 31%, and peak consumption by 35%.

“The early adopters are the ones who require continuity,” says Roudet. But microgrids could also find a use in factories that are close to the limit in terms of how much power their existing infrastructure can support.

He gives the example of a public venue such as a stadium adding charging points for electric cars, where peak use would be high, but rare. “Those sites have to be updated and upgraded, and you may have to completely redesign your power distribution,” he says.

A decarbonised microgrid offers an alternative option. “You can avoid those peak points and keep using that infrastructure without having to upgrade,” he says. This power can help facilities ride the peaks, and offer an extra income source if they sell electricity to the grid when it’s not needed.

Diesel generators are the go-to solution for back-up power but, as the price of batteries falls, renewables could become an important part of the mix.