For several years now, there have been considerations about how to improve the air quality in the service area of the German bus operator wupsi (formerly Kraftverkehr Wupper-Sieg AG). The options for transforming diesel buses into battery or hydrogen buses were studied in detail by ebusplan. finally the electrification of one line between Bergisch Gladbach and Leverkusen was suggested. With the acquisition of the first ten battery-powered vehicles by 2022, wupsi is taking an important step towards low-emission bus transport.