Capstone Turbine working with Kenworth and Peterbilt on heavy-duty microturbine range-extended trucks
Axeon supplying two 25 kWh Li-ion packs for range-extended electric van concepts

UC Riverside team receives $2M to evaluate emission reduction benefits of hybrid bulldozer and excavator

Purported benefits of the Caterpillar D7E Electric Drive Track-Type Tractor. Click to enlarge.

Scientists at the University of California, Riverside’s Center for Environmental Research and Technology have received a $2-million contract for a first-of-its-kind study of hybrid construction vehicles. The two-year project, which is being funded by the California Air Resources Board, will allow researchers to evaluate the emission reduction benefits of two commercially available hybrid construction vehicles: a Caterpillar bulldozer (earlier post) and a Komatsu hydraulic excavator (earlier post).

Little is known about the potential benefits of hybrid technologies for construction equipment because of their unique and diverse duty cycles when used. Manufacturers are saying the hybrid vehicles reduce fuel needs by 20% and cut emissions by 30%, said Kent Johnson, an assistant research engineer at the Center for Environmental Research and Technology and the principal investigator on the project.

Johnson will be assisted by two co-principal investigators: Tom Durbin, a research engineer, and Wayne Miller, who lead the emissions and fuels research group at the Center for Environmental Research and Technology.

Half of the funding will be used as an incentive voucher to get 20 to 30 hybrid construction vehicles in use. The other half will fund testing in six vehicles, which will be scattered throughout California.

Behavior of those vehicles will be characterized on a second-by-second basis during in-use operations at construction sites using portable emission measurement systems. Researchers will design standardized tasks, such as lifting a heavy object. The performance of the hybrid vehicle will then be compared to that of conventional diesel powered vehicles.

The project will help establish the methodology for making comparisons under such varied conditions. The project will also consider the differences between emerging hybrid implementations by leading manufacturers.

The research is part of a larger effort by the California Air Resources Board to expand the use of hybrid technology to help meet the goals of AB 32, a 2006 state law that aims to reduce greenhouse gas emissions to 1990 levels by 2020. That would be about a 30% reduction. It also calls for an 80% reduction below 1990 levels by 2050.

The project may provide data that could contribute to a hybrid incentive program under AB 118, a 2007 law that established voluntary incentive program administered by the California Air Resources Board to fund clean vehicle and equipment projects, research on biofuels production and the air quality impacts of alternative fuels, and workforce training.

The project is the latest in a nearly 20-year history of emissions testing at the Center for Environmental Research and Technology. Initial research focused on cars in a stationary setting. Later projects shifted trucks and on-the-road testing. Today, much of the work is done with portable emission measurement systems (PEMS), which have been used on everything from on-road and off-road vehicles, stationary sources, locomotives, port vehicles, air craft, harbor craft, and ocean-going vessels.



The 10,000,000 heavy diesel powered trucks and buses on our roads and streets should receive the same treatment. The impact would be multiplied.

Henry Gibson

The information that Caterpillar funded NOAX to make a free piston hydraulic pump to see if it would reduce energy losses for its equipment is probably lost from the Internet. The pump was built and tested in pallet lifting equipment with much success. Artemis, NOAX and other technology can be used to give good control and energy regeneration at low cost. An opposed piston variant, remember Pescara, of the NOAX free piston pump could be even more efficient than the recently announced Achates engine which seems so far to be a nice recreation of the Commer Knocker.

Artemis demonstrated that very complex, very efficient computer control of hydraulic pumps and motors is possible.

Hydraulic hybrid vehicles seem to be the most cost effective choice now.


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