Toward Zero-Emissions Construction Sites: Mobile Battery Energy Storage Units Charged from the Regenerative Braking Energy of Traction Grids

Zero-emissions construction sites are a key part of the energy transition. Their energy supply can be ensured by mobile battery energy storage units as is currently being commercialized. However, the charging of these batteries is still limited by the grid congestion and the existence of a suitable charging infrastructure. Meanwhile, traction grids are notoriously underutilized high-power infrastructures with a significant amount of regenerative braking energy that is predominately wasted as heat in braking resistors. This paper suggests charging the construction sites-destined mobile batteries from the traction grids to harvest their otherwisewasted braking energy and relieve the congested distribution grid. The paper examines 7 different charging schemes for different battery sizes in four case studies of low- and hightraffic metro and trolleybus grids in Amsterdam and Arnhem, respectively. It is found that up to 88% of the battery charging can come from the otherwise-wasted braking energy.