Between May 2010 and January 2011, Broward County Transit (BCT) in Pompano Beach, Florida, used a $2 million TIGGER award to replace bus cooling systems on 80 of its 288 buses and achieved a 5% reduction in fuel use.

BCT replaced the mechanically/hydraulically driven cooling systems with MiniHybrid Thermal Systems from Engineered Machined Products. The MiniHybrid Thermal System is a fully contained system that replaces the original equipment manufacturer-supplied bus alternator and cooling system with a high output alternator and a cooling package of heat exchangers and eight electronically controlled electric fans. The MiniHybrid kit includes temperature sensors for the engine charge air and engine jacket water flow paths in order to optimize cooling of those systems separately.

By integrating vehicle efficiency technology into 80 buses, BCT not only reduced fuel use, but also increased the average fuel efficiency of its fleet vehicles by approximately 5%, enhanced bus performance, and reduced greenhouse gas emissions. Project partners, Electric Sales & Services and Engine & Accessory, Inc., assisted with the technology integration.

Prior to this TIGGER project, BCT tested MiniHybrid Thermal Systems on five of its 2005 NABI buses, and documented fuel savings of up to 8%. Based on these positive results, BCT used the TIGGER project funds to extend the retrofit to 80 other buses in the fleet.

As demonstrated by this project, the MiniHybrid Thermal System could be used by other transit agencies to retrofit existing transit fleets to achieve fuel savings and reduce greenhouse gas emissions.