Hydraulic Hybrid Vehicle Demonstration

This report examines the benefits of Parker Hannifin's hydraulic hybrid brake energy recovery system, which is intended for use in commercial refuse trucks. The hydraulic brake energy recovery system was field-tested in high start and stop applications to determine the magnitude of fuel and emissions reductions. Additional study topics included productivity, driver acceptance, and maintenance. During low speed, high start and stop driving tests, the refuse vehicles had 49 percent better fuel economy performance over the baseline diesel, plus a 30 percent reduction in CO2 emissions per mile. This represents a substantial improvement over baseline technologies as approximately 80 percent of a refuse vehicle's time is spent in low speed operation. Field-testing data showed similar improvements in performance, with an average fuel economy of 2.8 mpg, which represents a substantial improvement compared to the low speed dynamometer test result of 0.88 mpg. Continued review of data in the areas of reliability, driver acceptance, and reduced maintenance would allow for expanded research for these platforms. Investigation of this solution for other vehicle platforms, such as shuttle and transport buses, combined with natural gas fuels, could yield interesting growth opportunities and new commercial applications.