11 September 2018

Electricity storage, the real challenge of renewable energies

In a world in the middle of an energy transition, storing energy produced by the sun or wind in order to release it during the night, in times of bad weather or when there is no wind, is a real challenge. The Belgian company CMI (Cockerill Maintenance & Ingénierie) provides integrated production, storage and management units for green electricity. A promising solution towards using renewable energies, doing away with their major drawback: their intermittent production.


CMI Energy’s research team has highlighted the opportunity to develop storage solutions for electricity produced by photovoltaic panels or wind turbines. Both sectors suffer from the same major drawback, which is their intermittent electricity production, seeing as both depend on the presence of either sun or wind. Coupling them with storage technologies gives them an undeniable edge: full control of the use of stored electricity.

CMI Energy Storage is currently building the largest industrial energy storage pilot site in Europe, on a site in Seraing in Belgium. This installation will include over 2 MWp of photovoltaic panels covering a surface area of 10,700 m2, combined with two types of batteries (flow and lithium-ion), totalling over 4 MWh of stored energy, which will be able to operate on and off line. This installation will be operational in the summer of 2018.


The main advantage of storing energy in batteries is the energy transfer, which consists in storing energy produced during the day (when production is high) and using it later in the evening (when consumption is high). This system means that electricity can be supplied on demand, and guarantees greater autonomy compared to a traditional power grid, and can even ensure total independence from power grids in non-connected areas.Supplying green energy to sites that are geographically isolated and have less energy requirements would thus become possible.

As an electricity specialist, I’m responsible for, or contribute to, all the electrical aspects of this project: sizing of AC/DC power cables, developing a strategy aimed at controlling the entire photovoltaic + battery system, designing general low-voltage panels, and assessing and comparing the technical capacities of the various suppliers, etc.

Hamid S. 

Electrical Engineer