NexGenHyBus will develop a mild hybrid architecture for fuel efficient buses. Wrightbus has successfully developed three generations of "micro-hybrid" architecture. These systems recuperate braking energy and use it to power ancillary systems rather than vehicle propulsion. NexGenHyBus will build on previous micro hybrid architectures. Retaining those system features of extensive ancillary electrification, drive assist will be added at a fraction of the cost of a full (high voltage) hybrid system. The project will examine a range of possible mild hybrid architectures with specific provision made for vehicle systems with a significant air-conditioning load to be provide by electrically driven compressors. A dual battery system will be developed with battery storage and electric motor/generators. Extensive modelling simulation and testing activities will be undertaken by Queen's University Belfast. Vehicle trials will be undertaken by Go-Ahead Group.