Lightning Hybrids, developer and manufacturer of the Energy Recovery System (ERS) for medium- and heavy-duty trucks and buses, announced an agreement with Norfolk, Mass.-based Kiessling Transit, which will almost double the number of hydraulic hybrid buses in its fleet.

The 32 unit order follows an order last year from the company for 35 units that were commissioned in September 2015. Those vehicles have recorded close to a total of one million miles. The ERS has demonstrated improvements of 25% in fuel efficiency and significantly reduced tailpipe emissions. In addition, Lightning Hybrids has identified ways to reduce vehicle idle time by up to 30%.

Kiessling Transit has received a grant from the Commonwealth of Massachusetts that pays for 80% of the cost of the Lightning Hybrids’ systems to be installed on Kiessling Transit’s Ford E-450 passenger buses, making them cleaner, more fuel efficient and improving braking efficiency.

The ERS is a patented, parallel hydraulic hybrid system that has no electric batteries. Instead, it applies a hydraulic system to the driveline of a vehicle to regenerate braking energy. Hydraulic pumps and a lightweight accumulator brake the vehicle, store the energy and then use that stored energy to provide power to the wheels.

When put in service, the buses will provide an immediate positive impact on the environment due to the reduced emissions of the system. For example, vehicles with Lightning Hybrids’ technology produce half of the NOx emissions and 25% fewer CO2 emissions, compared to vehicles without the company’s system, according to Lightning Hybrids. In addition to these emissions reductions, the Kiessling fleet will see decreased fuel use, longer brake life, better low-end torque, and lower maintenance and operational costs.