A solar bus or solar-charged bus is a bus that is powered exclusively or mainly by solar energy. Solar-powered bus service is referred to as a solar bus service. The use of the term "solar bus" normally implies that solar energy is used not only for powering electric equipment on the bus, but also for the propulsion of the vehicle.

A battery electric bus is an electric bus that is driven by an electric motor and obtains energy from on-board batteries. Many trolleybuses use batteries as an auxiliary or emergency power source.