This paper presents the enormous advantages of applying modern trolleybuses on Bus Rapid Transit systems - BRT-, to ease the electrification of public transportation with all the consequences that this implies: reduction of energy consumption, substitution of fossil fuels, improvement of air quality on cities and travel experience. As a case of study the hypothetical consequences of the electrification of Transmilenio, one of the largest BRT in the world, are presented. ©2010 IEEE.