Commentary: Don’t Write Off Hybrids

We have heard over and over lately that electric and hydraulic hybrids for commercial trucks are all but dead, pushed to the back of the room by the surging interest in natural gas. Eaton, in fact, quietly dropped production of its Hydraulic Launch Assist system, though it continues to invest in improvements to its diesel-electric hybrid product.

Is the industry being short-sighted? In the long run, hybrids have the potential to save far more fuel than natural gas engines alone.
Natural gas is generating a lot of interest because it is a clean-burning, cheaper alternative to diesel with an abundant domestic supply. And that’s great.

But it’s still simply replacing one fossil fuel with another one.

There are also concerns that the hydraulic fracturing process that is powering North America’s natural gas boom could have harmful environmental side effects that negate the “greenness” of the clean-burning fuel.

In contrast, hybrids allow trucks to use less fuel and cleverly capture energy that would otherwise go to waste during coasting and braking.

There are other benefits to hybrids for certain applications. For instance, diesel-electric hybrids are popular with utility fleets, where bucket trucks are able to operate their lift apparatus in residential areas without engine exhaust and noise pollution. Refuse fleets using hydraulic hybrids report significant savings in brake maintenance costs.

And here’s a thought – hybrids could be used in tandem with other “green” fuels.

For instance, an electric or hydraulic hybrid could also have the diesel engine portion of its drivetrain running on biodiesel. We feature two fleets in this issue who are doing just that with biodiesel and electric hybrids, one in the power business, the other in beverage distribution.

Hybrids and natural gas could be used together for a “best of both worlds” scenario.

Eaton is already running about 600 natural gas/electric hybrids in other countries. The two technologies work well together, Eaton says, with the hybrid system complementing the CNG engine for better performance.

Hydraulic hybrids, which are still being made by Parker, also could be paired with natural gas instead of diesel engines. Parker is working on just such a project with Autocar for its RunWise system.

And for refuse fleets where hydraulic hybrids make the most sense, they could be paired with a renewable resource: methane gas recovered from landfills.

Meanwhile, strides are being made to improve the “value proposition” of electric hybrids.

When Eaton started offering its diesel-electric hybrid system six or seven years ago, it was tough to find manufacturers who were capable of building the batteries, electric motors and other component. Today, they say, it’s easy to get reliable components, and they are coming down in price and improving in capacity.

Eaton’s newest system offers three times the battery capacity for better fuel economy and thus faster return on investment.

Meanwhile, other companies are entering the market with new ideas.
EPower Engine Systems believes it has the answer with a series (rather than Eaton’s parallel) hybrid that doesn’t need a transmission and uses lead-carbon batteries instead of lead-acid batteries. Odyne has developed a plug-in hybrid and recently received a contract to outfit about 120 utility trucks under a $45 million contract with the research arm of the utility industry. And Hino’s offering a Class 5 hybrid-electric truck.

Keep your eye on hybrids for commercial trucks. While they are simply one alternative among many fleets will be able to choose from in the near future, the time will come when hybrids will make economic as well as environmental sense for a larger portion of the industry. For some fleets, they already do.