Picture the typical driver of a hybrid vehicle over time. A decade ago what likely would have come to mind was a Sierra Club member, raised on Willie Nelson music, who thought globally and acted locally. More recently one might have imagined a professional who traded the two-ton SUV for a Prius when gas prices began exceeding eighty dollars a tank. But the image that probably never crossed the mind was a city bus driver in India, nudging his way through the crush of Calcutta’s commute. Yet this is exactly to whom Guy Babbitt and his company CZero (along with collaborators at CSU) were trying to bring hybrid technology.
CZero’s focus is on hydraulic hybrids which store energy when a vehicle brakes. Hydraulic hybrids are different from electric hybrids in that they are able to capture a large amount of power and return the power over a very short amount of time as opposed to the battery of an electric hybrid which gives back less power over a much longer duration. This fact makes hydraulic hybrids ideally suited to vehicles that are frequently starting and stopping. “Trash trucks are really the holy grail given their driving cycle” explains Babbitt.
Hydraulic hybrid technology starts at the brakes where hydraulic pumps capture the energy released as a vehicle decelerates. The energy is then stored in an accumulator which can take the form of a piston or rubber bladder filled with compressed gas – usually nitrogen. When the car goes to accelerate the energy stored in the compressed gas is released directly to the driveshaft.
Making hydraulic hybrids economically attractive is a function depending on much the same factors as electric hybrids – the cost of the system, the efficiency gains, and the fuel prices. Costs for hydraulic hybrid systems are driven by two components: The hydraulic pumps that require precision machining, and the tank, which contains the energy accumulator and therefore must be constructed of materials able to withstand about four times the 5000 psi operating pressure.
Fuel efficiency gains are likely to be in the 20-40% range depending on the system and vehicle’s driving cycle. Test vehicles are already on the road using Eaton’s Hydraulic Launch Assist (HLA) technology in the types of vehicles where the economics are likely to be most favorable – garbage and delivery trucks. Eaton claims fuel efficiency improvements of 25-35% which could turn into some pretty big savings – Denver Public Works (which is currently testing a Peterbilt Motors garbage truck with HLA technology) estimates that its fleet averages about 2.3 miles per gallon. Along with improved fuel efficiency, another benefit of hydraulic hybrid systems is less wear and tear on the traditional friction brake systems. The regular brakes only need to kick in at times when the hydraulic braking system is insufficient, minimizing the need for brake maintenance and keeping trucks on the road instead of in the shop.
| Company Basics | |
|---|---|
| Location | Fort Collins |
| President | Guy Babbitt |
| Vice President | Chris Turner |
| Website | www.czero-solutions.com |
CZero is still trying to figure exactly how and where it will fit into the growing market for hydraulic hybrid technology. They expect to leave the original production of new hydraulic hybrids to the global manufacturers, and have therefore fixed their focus on converting existing vehicles into more efficient hybrids. The firm has an initial prototype of a retrofit kit that would accomplish this, as well as a grant to develop a second prototype which Babbitt hopes will improve fuel economy gains over the first generation model. The company may try to commercialize the whole retrofit kit, which could serve as an option for firms or municipalities looking to improve fuel economy on their existing fleet without committing to as large a capital expenditure as purchasing new vehicles.
Babbitt also sees the opportunity to optimize specific pieces of the design as well as the potential to develop some IP around specific components. Still other possibilities include collaboration with manufacturers: “We may end up just making a component or piece of a product that gets to market and then licensing or selling it.” The CZero team could also see using their development experience to serve as integrators in the production of a retrofit system utilizing components from companies working toward the same goal.
Along with development of hydraulic hybrid technology, CZero is supplementing their current grant funding through “bootstrapping by consulting,” as Babbitt puts it. The expertise and experience of Babbitt and co-founder Chris Turner prove a good match for a lot of companies trying to bring a device from the lab bench to a robust design. In this process the duo also believes they have a good feel for when modeling versus prototyping makes more sense. CZero’s consulting clients include Solix as well as other biofuel companies in the area.
For now there is no penalty for not picturing the eco-friendly Indian bus driver, as that project is still in the planning stages. According to Babbitt, “It really would have had to be the perfect storm of factors for them to want to [adopt the hybrid technology] immediately.” The team faced both skepticism that the system could generate significant fuel savings and an unwillingness to make the needed investments on the part of fleet owners. But whether it is as the maker of a whole system or the optimizer of a particular component, Babbitt remains hopeful that one day CZero will be a part of bringing hydraulic hybrid technology to markets like India as well as improving efficiencies at home.
