The Brihanmumbai Electric Supply and Transport (BEST), Mumbai's bus service, is introducing emission-free electric buses today. Four such buses will be added to the city's fleet and will ply on seven routes in South Mumbai. This move is intended to help cut fuel cost and provide environment-friendly solution to the congested city. The electric buses will be launched by Yuva Sena chief Aaditya Thackeray at Wadala depot.