EV’s? Here Come the Hydraulic Hybrids

By Kennedy Maize

Washington, D.C., January 24, 2011 — While many of us have fixated on electric approaches to vehicle propulsion, the U.S. Environmental Protection Agency has been working on another technology that may turn out to be a killer ap for conventional gasoline cars. Earlier this month, with little fanfare or hoopla, Chrysler announced that it will roll out a Town & Country minivan with an internal combustion engine powering a hydraulic motor. Chrysler said it is considering the technology for its signature 300 sedan, as well.

The Detroit-based car company (unofficial motto: we’re number three) made the announcement, not at the storied Detroit Auto Show, which was going on at the same time, but at EPA’s National Vehicle and Fuel Emissions Laboratory in Ann Arbor. CEO Sylvio Marchionne (also the head of Italy’s Fiat, which owns Chrysler) said his company will test a dozen or so minivans next year. If they work well, they could be on the market by 2013.

EPA Administrator Lisa Jackson touted the technology her agency has been working on for 15 years, saying that it can improve energy efficiency by 35%, cut greenhouse gas emissions from each vehicle by 40%, adding only 15% to the base price of the vehicle. EPA and its private-sector research partners have deployed the gas-hydraulic engines successfully in some UPS delivery trucks, and in off-road trucks used to transfer shipping containers at the ports of New York, New Jersey, and Rotterdam in the Netherlands. Jackson said EPA will put $2 million of its funds into the Chrysler project.

The hybrid technology appears to fit well with American habits and tastes in vehicles, which tend to run to large and powerful. The Ford F-150 light-duty pickup truck has been the best-selling vehicle in the U.S. for 29 consecutive years. Ford’s revamped Explorer SUV, which is getting rave reviews, was named “Car of the Year” at this year’s Detroit show along with the Chevy Volt plug-in hybrid. (For a commentary on the future of electric vehicles in the U.S., see my article at ElectricityPolicy.com)

The EPA technology uses an internal combustion engine to power a pump that pushes hydraulic fluid into a device called an “accumulator.” It stores the fluid at a high pressure, maintained by pressurized nitrogen gas. The hydraulic fluid drives motors that turn the vehicle’s wheels.

According to the EPA, the hydraulic hybrid offers regenerative braking recovering over 70% of the energy normally wasted during braking; optimum engine control without the need for a drive shaft and transmission and without the weight of batteries; and the ability to completely shut off the gas or diesel engine when not needed, which is most of the time in stop-and-go driving.

EPA claims the technology is quite versatile, useful in cars, light-duty trucks (including SUVs), and heavy-duty urban vehicles. It also pairs well with advanced diesel engines, developed in Europe, that offer large efficiency gains compared to gasoline engines. The technology can also work on tiny applications, according to the agency, which is working on a people-powered hydraulic hybrid bike.

In touting the technology — which had its origins in a Clinton-era government-private program called the Partnership for a New Generation of Vehicles — EPA stresses its simplicity. It “does not require breakthroughs to be cost effective or to be manufactured, and can be produced with the skills and manufacturing base already available in the U.S.” In the face of the demands of gas-electric hybrids and all-electric cars for exotic rare earth metals, EPA notes that the hydraulic technology “doesn’t rely on complicated or expensive materials…”

Will hydraulics chase electricity out of the vehicle market? That’s hard to tell, as the electrics have a large head start, with real vehicles for sale to real consumers. But those consumers will be the ultimate decision makers. They have chased electric vehicles out of the market before. A hundred years ago, electric cars were the choice for discriminating buyers such as Clara Ford, who preferred her 1914 Detroit Electric Brougham to her husband Henry’s loud, smoky rattletraps.