The electrification of public transport is a key step towards climate neutrality. To ensure investments are not only economically but also ecologically viable, we assess the full lifecycle of vehicles, batteries and infrastructure. With robust CO₂ balances (life cycle assessments), we include production, operation, maintenance and decommissioning. Batteries are a particular focus: in addition to optimisation for vehicle use, we develop second-life scenarios and analyse take-back and recycling paths to promote circular economy. For charging infrastructure, we evaluate construction methods, material use and energy supply with regard to emissions and resource efficiency. This gives companies a transparent basis to make ecological impact measurable, secure funding eligibility and implement projects with public acceptance.