Reducing energy bills despite soaring energy prices

Eaton’s Le Mont-sur-Lausanne office (1,650 m²) forms part of a mixed-use building, which also contains a kindergarten, a shop, and underground parking. The Buildings as a Grid approach that Eaton has implemented there comprises a 100 kWp rooftop solar PV array, an Eaton xStorage battery energy storage system (20 kW power and 21 kWh capacity), 16 EV chargers located in Eaton’s underground parking garage, and a DC fast charger located adjacent to the parking bays outside the building for the public to use.

Eaton’s proprietary Buildings Energy Management Software (BEMS) is used to optimise the use of all the solar energy generated from the rooftop array. Powerful algorithms within the software automatically direct power to where it is most needed for EV charging and other electrical requirements in the building, with any surplus stored in the xStorage battery to substitute power from the grid when prices are highest at times of peak demand. Surplus can alternatively be sold to the grid, if required, with resulting revenue used to offset energy bills.

Since July 2022, the Buildings as a Grid approach at Le Mont-sur-Lausanne has been monitored. Statistics were collated for the period from July to December 2022 to show how money and carbon emissions were saved by offsetting the power the building needed from the grid with renewable energy from the solar panels.

Eaton was aware that the Le Mont-sur-Lausanne building must also be energy efficient to perform successfully as an energy hub, so the company asked its new partner, IES, the world-renowned building analytics firm, to develop a digital twin of the building to interrogate the infrastructure and work out how even more energy savings could be made.

The digital twin showed how energy and carbon emissions could be reduced by a further 30% representing a total cost saving of 1,540CHF (approximately €1,550) per year, while at the same time enhancing the comfort of the building’s users through measures such as optimal use of window shading to maximise daylight use and prevent solar heat gain.

A digital twin is a 3D digital representation of a built environment asset - a building or its supporting infrastructure, for example - that can be interrogated by running various scenarios to inform decisions about its future. Learning from the asset’s past performance leads to better decision-making when developing a roadmap for its future. 

Learn more about the Buildings as a Grid approach and discover how its ecosystem transforms both new buildings and renovation projects into energy hubs that optimise energy consumption while at the same time supporting a flexible, scalable EV charging infrastructure, renewable energy generation, and energy storage.