The electrification of public transport offers the opportunity not only to consume energy but also to actively participate in an intelligent energy system. With photovoltaics, stationary storage and smart load management, a system is created that combines security of supply, cost efficiency and climate protection. We prepare feasibility and cost-benefit analyses, assess PV integration at depots or catenary points, and analyse the use of storage – including second-life batteries. Detailed load and environmental models show how self-production smooths peak loads, reduces grid connection costs and increases self-consumption. The result is a smart grid solution that makes investments economical, reduces operating costs and maximises ecological impact.