Empa, ETH Zürich and Bucher Municipal have developed a hybrid-electric powertrain for road sweepers that's said to consume half the energy of diesel-hydraulic vehicles and reduce emissions by more than 60 percent.
The design replaces conventional hydraulic power distribution with a more efficient electric drive system. A small natural gas engine with a power generator acts as the drive source.
The main goal of the project was is to offer a cleaner and more efficient alternative to diesel sweepers while keeping costs on par with current technologies. Why sweepers? These vehicles spend seven hours a day at work and guzzle up to 10,000 liters of diesel per year, more than 10 times what a passenger car uses, the team say.
While upfront costs of the vehicle may be higher, operational costs are offset by the use of natural gas, which can consume around 50 percent less throughout a standard working cycle according to the researchers. Natural gas also contains less carbon, which accounts for significant reductions in GHG emissions. They predict that with a biogas blend, the hybrid sweeper would be even greener.
Thanks to its modular design, other sources of power could also be used in the sweeper, including an all electric drive or a hydrogen-powered fuel cell – an approach used previously in the CityCat H2.
Bucher Municipal's management is now planning to further develop the vehicle's modular platform and examine the production processes needed to bring it to market, something which the company hopes to do in the "foreseeable future."