“There are a lot of ways to move a vehicle down the street”.
That’s what John Kargul, Director of Technology Transfer at the EPA’s Office of Transportation and Air Quality, told me in Atlanta earlier this week. We were discussing the various concepts in alternative fuel vehicles and propulsion systems that are little known yet still hold great promise in meeting our transportation and energy challenges.
Until Monday, the Hydraulic Hybrid Vehicle (HHV) was one of those little-known concepts promising significant potential for increased fuel efficiency and reduced carbon emissions.
After two years of road testing done in a “real world laboratory”, working UPS routes on the streets of Detroit, that potential has proven itself ready for the marketplace, and UPS has stepped up to the plate as the first corporate buyer of HHV technology. The company has purchased seven HHV trucks to be deployed throughout 2009 and early 2010, starting in the first quarter of ‘09 with two HHV trucks plying the streets of Minneapolis.
Increased efficiency and reduced emissions
When testing the HHV on delivery routes, UPS reported a nominal 45–50% increase in fuel efficiency over a standard diesel UPS delivery truck, with a 33% reduction in CO2 emissions (the EPA has results as high as 60% increase in fuel efficiency). Using the hydraulic hybrid system in series with a small, highly efficient diesel engine, the HHV is particularly suited for the short-haul start/stop urban duty cycle of a city-bound UPS truck (UPS would prefer I call their delivery trucks “package cars”, but for clarity, I’ll stick to “truck”).
One piece of the puzzle
HHV technology is not intended as a be-all, end-all solution. Speaking at the press conference in Atlanta this past Monday, UPS Chief Operating Officer David Abney said:
“There is no question that hydraulic hybrids, although little known to the public, are ready for prime time use on the streets of America. We are not declaring hydraulic hybrids a panacea for our energy woes, but this technology certainly is as promising as anything we’ve seen to date.”
With the largest fleet of alternative fuel vehicles in the industry, UPS looks to HHV as one more piece of the puzzle toward creating a total picture of sustainability, efficiency, and reduced emissions throughout their global operation.
Power control vs. power density – how HHV works
Power density is one advantage of an HHV in the urban duty cycle over the “traditional” battery/engine hybrid. As Kargul explained: “electrons equal control of power, hydraulics equal high density power”.
The HHV is able to produce high torque power to move the vehicle forward using a “series hybrid hydraulic drivetrain (SHHD) consisting of hydraulic pumps and two “accumulator tanks” that store energy. The system replaces the traditional drivetrain and transmission, moving the wheels by pumping hydraulic fluid between the high and low pressure accumulator tanks. Once the vehicle is cruising and the hydraulic fluid in the high pressure pressure tank drains to a specified level, the diesel engine kicks in and drives a hydraulic pump re-pressurizing the low pressure fluid that continue to drive the wheels. The highly efficient diesel engine is designed to run at a constant “sweet spot” speed. The engine shuts off when the vehicle is decelerating, braking, or stopped, adding to that efficiency.
When the driver presses the brake peddle, the vehicle is slowed using its own kinetic energy to pump low pressure fluid back through the pump motor into the high pressure accumulator. When light turns green and the driver presses the accelerator peddle, this stored energy is used to get the vehicle moving. 70% or more of the kinetic energy is recovered through this regenerative braking process. See my previous post for a short video displaying how HHV works.
Using the hydraulic system to slow the vehicle means that under normal breaking conditions, brake pads aren’t used. For safety and situations such as braking on icy roads, an ABS system is in place, but by using the vehicle’s own kinetic energy to slow down, further operational cost savings are possible through reduced maintenance costs.
Nitrogen is the “spring”
The two accumulator tanks in the prototype vehicle on display in Atlanta each have a 44 gallon capacity. Each tank holds equal amounts of common transmission fluid and nitrogen. If we think back to our basic physics class (a long way back for me), we’ll remember that it is much easier to compress a gas than it is a liquid, hence nitrogen is the “spring” that stores and releases the potential energy in the hydraulic system.
The capacity of the two accumulator tanks is slightly over-built on the prototype truck, according to Kargul, to help prove out the concept. Nonetheless, by using carbon fiber material for the tanks, an 80% reduction in weight is realized over steel tanks, a major component in the vehicles overall efficiency. Smaller tanks on future models mean, of course, even greater efficiency.
Cost and scaling
According to Abney, a UPS HHV delivery truck currently carries a $7000 premium over a standard diesel version. UPS is confident, Abney says, that costs will be recouped through reduced operating costs, thus their willingness to be the initial buyer of the HHV to help drive the technology forward. Scaling is key to realize both the economic and environmental benefits of the HHV, and with only seven vehicles purchased and low volume manufacturing, the required economies of scale may not be present for several years. Abney declined to estimate how long it will take for UPS to recoup the increased cost of the vehicle, but Chris Grundler, Deputy Director of the EPA’s Office of Transportation and Air Quality estimated pay back in three years or less. A typical UPS truck has a lifespan of up to 20 years.
The next phase of testing the seven vehicle purchased by UPS will work toward subsequent scaling of the HHV based on data and feedback from the initial deployment.
All this brings me to my last point.
Partnership is key
It was fascinating to see the HHV technology up close and personal, explained and demonstrated by some of the engineers involved in its production. But one of the most important elements in play with the “unveiling” on Monday was the importance of public/private partnership to find and develop solutions.
Bringing the strengths of each to the table offer the quickest, most efficient route of taking technologies like HHV from a mere concept to its full potential. Seven years ago HHV was unproven, untested, and expensive. The partnership between the EPA, Eaton, Navistar, and UPS offer, in my mind, a model of how it can and should work, demonstrating how the bottom line is best served through investment in sustainability. There are certainly risks for everyone involved in the project. But the risks are greater in doing nothing, both for the short term bottom line and for long term sustainability of business and the planet. Clearly the time is now, both for small innovative entrepreneurial start-ups that we avidly champion here at TriplePundit and for global corporations, to seize the opportunities and forge the partnerships that lead to innovation, sustained profitability and a livable planet.
Chris Grundler from the EPA said it thus:
“Partnership is key. Global enterprise should serve a broader goal than just the ‘bottom line’, but those choices are also good for business. At no time in my nearly 30 years in environmental policy have I seen the convergence of these interests more than right now. The problems we face – energy, our troubled economy, the very real dangers of climate change – offer challenges that demand solutions – and great opportunities.”
A message well delivered.
- The Environmental Protection Agency – Most people think of the EPA as a regulatory agency, and they’d mostly be right. But beyond what goes on in Washington is an ongoing effort in research and development of technology and systems that address the nation’s (and the world’s) need for alternative fuel vehicles that help reduce carbon emissions and our dependence on fossil fuel (both foreign and domestic). The HHV was developed at the National Vehicle and Fuel Emissions Laboratory in Ann Arbor, Michigan but they need private industry to design and build commercial applications that bring their research and development to market.
- Eaton Corporation – Eaton started collaboration with the EPA on the HHV project under a cooperative Research and Development Agreement signed in 2001, working on design and manufacture of the fluid control system of the HHV. Eaton has been listed as on the CRO Top 100 List of Corporate Citizens, and maintains an ongoing collaboration with the EPA on other technology development projects.
- Navistar – The HHV chassis was designed and is built by Navistar. The design combines the greatest degree of aerodynamics with the cubic capacity required of a UPS delivery vehicle.
- UPS – With the largest private fleet of alternative fuel vehicles, UPS has consistently shown the willingness to provide a market for innovative new ideas. This doesn’t just apply to their truck fleet, but in every phase of their business operations as well. Without a customer, the work of the EPA, Eaton, and Navistar could not be tested under real world conditions. By agreeing in 2006 to test the prototype HHV in the “field laboratory” of a real UPS route, the potential of the HHV concept has proven itself worthy of UPS’s confidence in purchasing seven vehicles with plans for continued scaling of the HHV as testing warrents and hopefully leading to a full-scale roll-out of HHV applications across the globe.