The City of Garland, Texas, Environmental Water Services Department, recently began a long-term field test evaluation of the Bosch Rexroth Hydrostatic Regenerative Braking (HRB) system to assess the technical, environmental and economic benefits of the parallel hydraulic hybrid system. Sponsored by the Houston Advanced Research Center (HARC) through a grant from the Texas Environmental Research Consortium and with funding provided by the Texas Commission on Environmental Quality, this evaluation program presents a potential solution for significantly reducing exhaust emissions.The goal is to evaluate the HRB technology as an alternative drivetrain system for the department, and upon successful project performance, potentially leading to wider adoption in refuse trucks in  Garland, the State of Texas, and nationwide.

The vehicle is a Crane Carrier LET2 with a Heil Environmental CP Python Rapid Rail automated side loader body. Two identical trucks will be outfitted with data collection systems so that comparison data can be obtained and evaluated. The trucks will be subjected to a variety of in-use testing, including braking tests, acceleration tests, route collection tests and dynamometer testing to evaluate emissions.

The HRB system captures a portion of the kinetic energy normally lost as friction heat during braking, storing it in the form of highly compressed gas for later use in assisting the engine in propelling the vehicle, reducing fuel consumption, wear on the brake system, and wear on the engine.

"HARC is pleased to sponsor this type of demonstration project. When proven successful, the technology will help the state of Texas improve air quality for the long-term benefit of our residents. We would like to see this important technology validated in the field so that it can be commercially available soon to reduce emissions and save fuel. I believe that, like the electric hybrid passenger car, hybrid technologies, such as HRB, are the right solutions for this type of heavy-duty application," says Dr. Yiqun Huang, HARC NTRD program director.

"We are excited to partner with the City of Garland as they enter into field trials," says Ken Hank, executive vice president, hydraulics, Bosch Rexroth. "With the HRB technology, we feel we can contribute to the achievement of the city's emissions and fuel savings goals."

Adds Tyra Lewis, Garland's project representative, "Fuel savings is a key component of our Environmental Management System (EMS) Program here in Environmental Waste Services. We saw this as an opportunity to explore new options to reduce fuel consumption while testing new technology."