Impact of Electrified Construction Machinery on the Electricity Grid An Analysis of Effects on Distribution Substations in Gothenburg from Charging of Battery-Electric Construction Machines

Abstract

The electrification of construction machinery is an important measure for reducing greenhouse gas emissions, local air pollution, and noise from construction sites. However, replacing diesel-powered machinery with battery-electric alternatives introduces new electricity demand patterns that may affect power demand in local distribution grids, particularly through high-power fast-charging and simultaneous peak loads. This thesis investigates how a fully electrified construction machinery fleet could influence the electricity grid in Gothenburg, with a focus on distribution substations operated by Göteborg Energi Nät AB. The study develops representative charging profiles for different construction site scenarios and combines these with historical substation load data from several urban area types, including industrial, commercial, and residential zones. By comparing charging demand with available substation capacity, the analysis identifies where and under which conditions capacity exceedance may occur. Different charging strategies, including reduced fast-charging power and night charging, are evaluated to assess their potential to mitigate grid impacts. The results indicate that electrified construction sites can create significant additional peak loads, especially when several machines charge simultaneously during working hours. The risk of exceeding available substation capacity varies depending on construction site size, charging strategy, substation rating, and local load characteristics. Industrial and commercial areas generally show different capacity margins compared with residential areas, while seasonal variation further influences the available grid capacity, with winter conditions being particularly critical. Reduced charging power and night charging are shown to lower peak demand and improve compatibility with existing grid capacity. Overall, the thesis demonstrates that the electrification of construction machinery is technically feasible but requires careful coordination between construction planning, charging strategies, and distribution grid capacity. The findings highlight the importance of integrating construction-related charging demand into future grid planning and provide a basis for identifying where mitigation measures or grid reinforcements may be required.