TOP PHOTO: Komatsu America Corp., BOTTOM PHOTO: Milwaukee Electric Tool Corp.
How Green? Komatsus hybrid excavator, which the firm says is 25% more fuel efficient than the standard model, is one of two machines to be tested.

If you are working out West and have been thinking about trying a hybrid construction machine, now is the time to take advantage of nearly $1 million in incentives available from the University of California, Riverside. The catch? Your new machine could take part in a statewide study designed to find out how “green” hybrids really are.

Working under a $2-million grant from the California Air Resources Board (CARB), the school's researchers will watch the machines work on real-life projects, such as a rock quarry, landfill or water remediation. Then, scientists will wire them up with sensors, run them through tests and compare their emissions to their non-hybrid siblings. Two hybrids will be tested: the Caterpillar D7E dozer and the Komatsu HB215LC-1 excavator.

Hybrid vehicles—which use internal-combustion engines and electric motors to cut down fuel consumption and, in some cases, store energy in a battery or other device—are common in the automotive sector. However, they are still new to the heavy-equipment space, some consider such machines as diesel-electric locomotives and mining trucks to be “prehistoric” hybrids. Cat started selling its green bulldozer in 2009, and Komastu rolled out its fuel-sipping excavator earlier this year.

Because the tests will take place on the job, evaluating the machines won't be easy. The challenge lies in the diverse conditions under which the vehicles work.

“We all drive cars pretty much the same,” explains Kent Johnson, an assistant research engineer at the university and the lead investigator. “Some construction equipment moves trash, rocks, trees, dirt. It's amazing.” Johnson recently appeared on the Discovery Channel show “Mythbusters” for a similar test comparing the relative emissions of cars and motorcycles.

California has a law on the books requiring regulators to study clean-fuel vehicles and deploy them into commerce, so CARB intends to use the tests to offer future incentive programs. Hybrid technology generally saves 5% to 20% in fuel and 25% to 70% in emissions.

Anyone wanting to participate in the study can fill out a voucher available at and take it to an authorized dealer. CARB is offering incentives of $75,000 for the D7E and $28,500 for the HB215LC-1, or about half the premium cost.