In a bid to increase their sustainability and self-sufficiency, MAINGAU Energie GmbH installed PV systems with a capacity of 300 kWp at their headquarters in Obertshausen. With more than 100 electric vehicles (EVs) regularly charging at the site, they wanted to harmonize PV production with EV charging to get the most out of their solar panels, without compromising user comfort. Because the time that EV drivers plug in their vehicles is not aligned with the highest PV-producing hours, they needed a sophisticated solution that takes all requirements into account.
On top of this, the site now features inverters, meters and charging stations from five different manufacturers, necessitating a comprehensive, device-agnostic energy management system. Finally, the site has a limited grid connection point, with a capacity of 630 kW. With 34 charging stations (each 22 kW) and 7 sub-distributions, it was clear that a small number of parallel charging sessions could easily disrupt the power supply. Holistic optimization would be key to overcoming these challenges.
By developing a dynamic load management solution on XENON that combines the Grid Protector and Remote Maintenance modules, MAINGAU Energie GmbH was able to manage the charging sessions in response to the building load and PV production.
The phase-exact management together with the multi-fuse feature ensure that limits are never exceeded at both the main fuse and at each of the 7 sub-fuses. In fact, across a 21-day period in June, the system prevented what would have otherwise been an overload on almost half of these days. The intelligent algorithms ensure that the charging load is only restricted when this would otherwise cause an overload, leading to constant maximization of charging power.
The seamless integration of mobility and electrical power enabled MAINGAU Energie GmbH to source 81% of their charging volume directly from PV. At the same time, employees’ mobility needs were always met. 80% of all charging sessions were fully completed. In the remaining 20% of sessions, the EVs charged an average of 21 kWh. Assuming a consumption of 15kWh/100km, this would provide 140km of range – more than enough to cover the average commute home.
“We at MAINGAU Energie GmbH are committed to reducing our carbon footprint by charging the electric cars on site with solar power,” says Ann-Christin Frensch, Project Manager (Project Management & Business Development Department). “But we didn’t want this to cause discomfort to drivers or overburden the fuses. gridX’s smart and holistic energy management solution allowed us to achieve all of these goals at once. By maximizing self-sufficiency, we were able to significantly reduce costs and emissions, while consistently meeting mobility needs.”
Upon electrifying its fleet, Bielefeld-based construction company, Goldbeck, realized the EV charging stations would exceed their grid capacity. XENON overcame this issue with an energy management system that enables smart charging.
A successful pilot project allowed the grid operator's control center to override the dynamic load management's local setting according to future energy regulation.