The EnergyCS plug-in Prius pushes mileage to well over 100 mpg, with several testers clocking more than 140 mpg on prototypes.
Lauren DeFreest and Matthew de Paula - ForbesAutos - July 31, 2006
Felix Kramer’s PHEV routinely gets more than 130 mpg.
A new strain of gas/electric hybrid vehicles called plug-in hybrid electric vehicles, or PHEVs, represent the latest wave of fuel-efficiency-boosting technology being explored by carmakers and third-party firms. They promise to boost gas mileage to 100 mpg and beyond by running only on rechargeable electric batteries for limited distances. As the name suggests, they can be plugged in to recharge.
Unlike gas/electric hybrids on the market now, which can't be plugged in, PHEVs require more batteries in order to run on electric power alone. So part of the process of converting an existing hybrid, such as the Toyota Prius, into a PHEV is to add more batteries, particularly newfangled ones like lithium-ion batteries, which are lighter and hold a charge longer than lead-acid or nickel metal hydride batteries.
No PHEVs are currently sold by major auto manufacturers, but Toyota recently pledged to pursue the technology and independent companies are working to convert existing hybrids into plug-ins. A small Southern California company called EnergyCS hopes to offer kits to convert 2004 and newer Toyota Priuses to PHEVs by the end of the year for a target cost of $12,000 per conversion, including installation.
But execs at big car manufacturers, such as Toyota and Ford, have said that PHEVs are still a long way off. And with some evidence that consumer interest in hybrid vehicles is beginning to wane (see Hybrid Downturn? section), PHEVs could face even greater challenges than simply developing reliable technology at a reasonable cost.
Best of Both Worlds
Proponents argue that PHEVs offer the best of both worlds: an alternative fuel source with drastically reduced emissions without the worry of running out of juice. Many viable plug-in electric vehicles have failed over the past decade because of one thing: They can't get very far on a full charge.
And neither can PHEVs when running on electricity alone. But a PHEV has the advantage of behaving just like a gas/electric hybrid when the batteries have been exhausted, and this gives them unlimited range - meaning that once the batteries run down, they can keep running on gasoline.
Plug-in Priuses currently being tested routinely get more than 100 mpg when driven in the city, thanks largely to their ability to operate only on electric power at speeds under 34 mph. By comparison, the soon-to-be-discontinued Honda Insight is the most efficient gas/electric hybrid currently available and returns an EPA estimated 60 mpg city/66 mpg highway.
Existing hybrid models generally run on gas and electricity at the same time - except the Prius, Ford Escape Hybrid and Mercury Mariner Hybrid, which already can run on electric power alone, but only for very short distances and at low speeds.
An extension cord plugged into a simple 110-volt household outlet can effectively charge the batteries in PHEV systems currently being explored by EnergeryCS, a small engineering firm based outside of Los Angeles in Monrovia, Calif.
This is an important facet to PHEVs' success. "It's existing infrastructure, so you don't have to build new charging stations to make this technology available to people," said Peter Nortman, president of EnergyCS. "These outlets are in your garage … everyone from a 10-year-old to a 95-year-old can handle it."
Being able to run on electric power alone for extended distances and be plugged in to recharge the batteries are the key differences between PHEVs and conventional gas/electric hybrids, which cannot be plugged in. They instead rely on clever techniques to recharge the batteries, such as capturing energy dissipated during coasting or braking.
Although PHEVs appeal to environmentally conscious consumers, they wouldn't be as appealing to buyers of luxury vehicles, says Art Spinella, president of CNW Marketing Research in Bandon, Ore. "Luxury hybrid buyers are looking for performance, they're not looking for fuel economy," he said.
Lexus promotes its hybrid GS 450h sport sedan, which is equipped with a gas/electric V8 powerplant, as offering performance comparable to that of a conventional V12. Toyota, which operates luxury division Lexus, wouldn't give specifics on PHEV plans, including whether it will explore Lexus PHEVs.
A major benefit of both current hybrids and future PHEVs is that their widespread use promises to not only reduce consumption of non-renewable fossil fuels but also curtail atmospheric pollution and greenhouse gases, which many scientists say cause global warming. A 2004 climate-change study by the California Air Resources Board found that gas/electric hybrid vehicles produce 62 percent fewer greenhouse gases than conventional gasoline-powered vehicles.
Ready to Roll
Current versions of EnergyCS' Prius plug-ins can travel 25 miles to 30 miles at speeds below 34 mph without the engine ever coming on. They take about eight hours to fully recharge from a 110-volt household power outlet.
EnergyCS is focusing initially on the popular 2004-and-newer Toyota Prius for building and testing its plug-in technology, though it plans to develop plug-in conversion kits for other models such as the Ford Escape Hybrid. The fact that the Prius can be readily converted to a PHEV creates "a strong statement to policy makers regarding the time to market for this near-term technology," said EnergyCS president Nortman, an engineer who has worked on alternative-fuel technology for more than a decade.
While a standard Prius gets an EPA-estimated 60 mpg city/50 mpg highway, the expanded electric power of the EnergyCS plug-in Prius pushes mileage to well over 100 mpg, with several testers clocking more than 140 mpg on prototypes. "You might forget what it's like to be at a gas station between fill-ups," Nortman said. "It's pretty neat only having to fill up once a month. It's quite a different driving experience."
EnergyCS chose not to mess with Toyota's original parameter that stipulates the Prius' gasoline engine cut in at speeds above 34 mph: The goal is to displace gasoline consumption with battery power, not alter the operation requirements for the car's transaxle, he said.
To convert a Prius to a PHEV, EnergyCS removes the standard 77-pound battery and installs a 231-pound lithium-ion battery pack supplied by Valence Technology, which adds a total of 154 pounds to the vehicle. The battery pack is stored under the floor of the luggage compartment after removing the spare tire and jack (see images above). A pound or two of additional wiring is also added.
The most obvious sign that a Prius has been converted to a PHEV is the plug-in outlet on the rear bumper, Nortman said. Prototypes also have a dash-mounted display that shows mileage and trip data (as shown on the previous page), but this is mainly for research and development purposes and might not be used on production versions sold to consumers, he said.
EnergyCS has developed new software and electronics that manage the power flow and interface with the car's onboard computer "so that the vehicle itself can't tell the difference between our system and the original," Nortman said.
Everything else on the car operates as normal, including the Prius' regenerative function that captures energy dissipated while braking and coasting and stores it in the battery.
The first plug-in Prius prototype was completed in fall 2004 and an updated one was publicly unveiled in April 2005. The company has more than 10 prototypes currently in use by environmental nonprofits (CalCars), California government organizations (South Coast Air Quality Management District - AQMD) as well as California utilities companies.
EnergyCS' own prototype has racked up about 40,000 miles so far, and the others are seeing about 2,000 miles of use per month. Data from tests and evaluations of these prototypes being driven daily are used to constantly refine the plug-in technology to make it more durable and reliable, Nortman said.
Nortman co-founded EDrive Systems to market and sell plug-in Prius conversion kits. He hopes to have kits available to consumers for $12,000, including installation, by the end of the year but isn't sure of the exact timeline to market. Currently it costs much more to convert and operate a plug-in Prius: The AQMD's two EnergyCS prototypes cost about $125,000, Nortman said.
Clean-Tech, an L.A.-based firm that develops and builds low- and zero-emission powertrains and is founding partner of EDrive Systems, will install the conversion kits initially. The goal is to add other certified installers nationwide, Nortman said.
EnergyCS is open to developing conversion kits for other hybrid vehicles and has looked into doing this for the Ford Escape Hybrid. But for the moment, all efforts are focused on the Toyota Prius.
Nationwide registrations for new hybrid vehicles jumped 139 percent from 2004 to 2005 to a total of 199,148 registrations, according to research firm R.L. Polk & Company. The Toyota Prius remains the top seller for the second year in a row comprising 52.6 percent of new registrations.
But purchase-intent data from CNW Marketing Research indicates that consumers might be losing interest in hybrids.
The price premium that consumers are willing to pay for gas/electric hybrids and the number of car-shoppers willing to consider buying a hybrid have both been dropping this year. CNW research shows that the average premium a new-car buyer is willing to pay for a hybrid peaked in the second half of September 2005 at $3,142. It has been declining ever since. The most recent figures from May put the average premium consumers are willing to pay for a hybrid at $1,957.
High fuel prices drove increases in the price premiums, Spinella said. The decline is likely a result of families having built higher gas prices into their household budgets and the availability of other fuel-efficient vehicles.
The number of new-car buyers willing to consider buying a hybrid vehicle peaked in the second half of November 2005 at 39 percent of those surveyed by CNW. As of May, that figure is down to 22 percent and it's certain that even fewer are actually buying hybrids. "Only about 60 out of a thousand people who consider a hybrid actually buy one," Spinella said. "To give you a reference point on that: Of every thousand people who consider a Toyota Camry Hybrid, about 350 buy them."
This reduced interest is one factor driving incentives for hybrid cars. While a year ago there were virtually no dealer incentives being offered on any hybrid model, according to CNW data, incentives for hybrids are rising quickly. Average out-the-door incentives (which include cash and other deals) in July 2006 for the Toyota Prius were $1,100; $1,400 for the Honda Accord Hybrid; $800 for the Honda Civic Hybrid; $1,600 for the Ford Escape Hybrid; and $1,900 for the Mercury Mariner Hybrid.
Building Critical Mass
Concurrent with its announcement to start working on PHEVs, Toyota announced plans to double the number of hybrid vehicles it produces as early as 2010. As of publication time, other car manufacturers that build hybrids had not publicly committed to moving forward with plug-in technology.
While sales of its Escape Hybrid SUV are up 37.8 percent in the first six months of this year, according to CNW data, Ford Motor Company has actually reneged the pledge it made last September as part of a high-profile corporate advertising campaign to have 250,000 hybrid vehicles on the road by the end of the decade. Ford is tepid about plug-in hybrid technology: “We have looked at plug-ins and, while they represent a valid technology, we believe they need to be better developed before they are viable for consumers,” said Ford spokeswoman Jennifer Moore. “We know that plug-ins add battery weight and that they still have reliability and durability challenges. It’s a technology that really needs further exploration.”
A chief concern among large automakers regarding PHEVs is the ability for the batteries to sustain the wear and tear of everyday use as they repeatedly get charged and drained. Battery longevity is the primary focus for Toyota in the near term with regard to plug-in hybrids, said Wade Hoyt, a Toyota spokesman.
While PHEV proponents and environmentalists are enthusiastic about hybrid plug-in potential, the average consumer will need some convincing. "We have done focus groups on plug-in hybrid, and for the most part it's met with pretty much a ‘show me’ kind of attitude. It's very apathetic, there isn't a groundswell of interest," CNW's Spinella said.
The added complexity of plug-in systems with regard to production and future maintenance is the key barrier for car manufacturers, he said. "Now, there's always a niche for virtually everything," Spinella said. "The problem is: Can you make a business case for it?"
EnergyCS' Nortman said that the high cost of plug-in systems is part of the process of pioneering and advancing technology. “People can’t make choices if they don’t have choices," he said. "We are at the point of having to explore different options. We need to walk before we run.”