Dec 7, 2006 (From the CalCars-News archive)
Edmunds.com has one of the larger and more diverse automotive websites, including a large section on Fuel Economy http://www.edmunds.com/fueleconomy/. The story that follows is written by their Consumer Advice Editor.
Plug-In Hybrids: Who Saved the Electric Car?
By Philip Reed
Date Posted 11-28-2006
Wouldn't it be nice if you had your own gas pump right in your garage? And what if gas from your personal pump cost less than $1 a gallon?
Sound impossible? Actually, that scenario might unfold if plug-in hybrid cars become a reality. Even better, a plug-in hybrid could be recharged by home roof-top photovoltaic panels so your fuel would be completely "off the grid" (not generated by a power plant).
Plug-in hybrid vehicles (PHEVs) have been in development for years and deliver amazing efficiency while slashing emissions. But while lagging battery technology has kept them from going mainstream, that could be changing very soon.
PHEVs are being embraced as the second coming of electric cars and promoted by such unlikely spokesmen as former CIA Director James Woolsey and former Secretary of State George Shultz. General Motors announced they will put a plug-in hybrid into production, based on the Saturn Vue. While no PHEVs are in production by automakers yet, private research companies such as EnergyCS, public action groups such as CalCars.org and utility companies such as Southern California Edison are saying PHEVs could curb global warming and end our dependence on foreign oil.
How PHEVs work Once the principle of the PHEV is explained, it often provokes a "why-didn't-they-think-of-that-sooner?" response.
Essentially, a PHEV is a hybrid car with a larger battery which can be recharged using household electrical outlets. On short trips, a PHEV operates like an all-electric car. If the driver decides to take a longer trip, and electric recharging isn't convenient, the gas engine comes on to recharge the batteries and propel the car. Thus, the PHEV has all the functionality of a normal gas car and most of the advantages of an electric car.
Research on plug-in hybrids began in the 1970s by engineering professor Dr. Andy Frank at the University of California, Davis. Since then he has converted a dozen cars to PHEVs. In one case, he swapped a Ford Explorer's 3.5-liter engine for a 1.9-liter power plant. After adding batteries and an electric motor the fuel economy increased and the acceleration was boosted.
The car of choice for conversion to PHEV is the 2004 and newer Toyota Prius. Interestingly, Asian and European Priuses have an "EV" button that allows short, low-speed trips in all-electric mode. The Prius sold in America doesn't offer the EV feature, but during the PHEV conversion the EV capability is restored.
Converting the Prius to PHEV In Monrovia, California, you'll see a number of Priuses parked outside a warehouse near downtown. This is the home of Energy Control Systems Engineering Inc., which converts hybrids to plug-in hybrids. At this time, the conversion costs more than an average consumer could afford and the payback period in gas savings would take a long time. Eventually, Pete Nortman, president of EnergyCS, hopes that, "As the price of batteries comes down and fuel prices go up you'll see the batteries getting bigger and the EV capabilities getting stronger."
Nortman calls plug-in technology a "revolution," one sparked by "looking at things that you have at your fingertips and putting them together in a way that is innovative." Nortman, along with Greg Hanssen, president of sister company EDrive Systems, has converted over 10 Toyota Priuses to PHEVs for utility companies and various city governments who are eager to test and display interest in the technology.
"We are doing our best to get real-world data that policy makers, OEMs [original equipment manufacturers] and utility companies can use to make decisions," said Nortman. "At some point, if the technology is commercially viable, EDrive will have a product that we can market."
"Oil is a finite resource," added Hanssen, who was featured in Who Killed the Electric Car? "Electricity is renewable in that we can generate it from different sources."
Test-driving the PHEV Hanssen gave us a test ride around Monrovia in a Prius converted to a plug-in hybrid for Manitoba Hydro in Canada. Other clients of EnergyCS include Pacific Gas & Electric, the Sacramento Municipal Utility District and the Southern California Air Quality Management District.
You can only see two differences between this plug-in hybrid and an ordinary Prius: an electrical socket in the rear bumper and a screen on the left side of the dashboard. The screen helps Hanssen know how to drive the car to take better advantage of the electric technology. As long as he stays below 34 mph and is easy on the accelerator pedal, the gas engine won't come on at all. Above that, the electric motor adds acceleration along with the gas engine. In both cases, the car has exactly the same acceleration as a standard Prius.
"The principle of the PHEV is to trick the car into thinking the battery is overly full so the engine doesn't come on," Hanssen said.
There are other differences below the skin, however. To convert the Prius to a plug-in they remove Toyota's battery pack, weighing 75 pounds, and replace it with a larger battery weighing 250 pounds. "It is like adding the weight of one passenger," Hanssen comments.
"People are seeing plug-in hybrids as a viable solution," Hanssen said as he drove through side streets. "No new infrastructure is required, no different driving style, the biggest obstacle is battery technology."
The car is quiet, smooth and - depending on how it's driven - can cruise in all-electric mode for about 30 miles. It gets to the point where you actually feel cheated if the gasoline engine has to kick in.
Carmakers question PHEVs Not everyone is PHEV-crazy. While Toyota is the leader in hybrid technology it remains cautious about plug-in hybrids. When the plug-in hybrid conversions were first announced, Toyota opposed altering its vehicles. Later, the car company said it would study the technology with the possibility of eventually offering it as an option.
"Toyota believes that plug-in hybrid vehicles have potential in the mid- to long-term," a Toyota spokesman said. "However, currently available battery technology [nickel metal hydride] is not capable of providing a suitable platform for PHEVs, because it would take inordinately large, heavy and costly battery packs to provide meaningful range extension. We believe that it will take some time until the next-generation technology [most likely lithium-ion] can perform to the levels that allow us to provide the same level of reliability, warranty, manufacturing and service cost."
When will PHEVs arrive? Dr. Andy Frank said the battery technology is "close but not yet proven" for carmaker's requirements. The lithium-ion battery technology "is not even five years old," he said, "so how can they guarantee it" for longer time periods?
However, Frank suggests that automakers could warranty the batteries for five years and 50,000 miles to start with (longer than the warranty on some domestic cars) and then increase the coverage as the technology becomes proven.
"New certification rules need to be created to encourage the PHEV to be introduced as quickly as possible since our global warming problems and oil depletion is accelerating, and it will be too late if we do not begin now," Frank said.
Felix Kramer, a California entrepreneur and founder of CalCars.org, believes that automakers could choose to put plug-in hybrids into production in the very near future. He points to a historic reluctance on the auto industry's part to adopt new technology despite a pressing need for change. "Buyers of U.S. cars could get excited all over again about advanced technology cars that help us become energy independent and contribute less to global warming," he said.
Same pollution, different source? On his Web site, Kramer debunks a commonly held assumption about electric cars, that they move pollution from the tailpipe to the power plant. "Two government studies have found PHEVs would result in large greenhouse gas reductions, even on the national grid" of up to 50 percent over coal, he writes.
Among many other benefits, Kramer also points to the fact that the electricity for PHEVs is largely domestic. "The nationwide power grid is less than 3-percent petroleum-fueled, whereas transportation is almost completely powered by oil - 60 percent of which comes from foreign sources [and growing]. Adoption of plug-in hybrids will transfer the overwhelming majority of our miles driven to nearly oil-free electricity."
Maximizing the electric power grid Utility companies would also benefit from PHEVs. Southern California Edison (SCE) has studied the feasibility of electric cars and PHEVs for years.
Edward Kjaer, director of Electric Transportation for SCE, notes that the power grid is sized to provide peak power during hours of high demand during the day, leaving a significant capacity unused at night. Recharging electric vehicles at night could help balance the load on the electrical grid.
"There are 20,000 megawatts available from 9 p.m. to noon," Kjaer said, which could easily be recharging 12 to 15 million plug-in hybrids. "This represents an energy security asset that is domestic based. As more and more transportation is electrified, what we ought to be doing is driving it to that off-peak asset."
Kjaer said that SCE's fleet of over 300 electric vehicles has traveled more than 12.5 million miles and hasn't experienced any major problems with the batteries.
He predicts that PHEVs will become available in the near future since there are currently three automakers aggressively working on their development. "Will it happen tomorrow? No," he said. But "politically we are beginning to get it, that we need to get off oil. It might take 100 years to get off oil, but we have to start today."
(Photos by Philip Reed) -Pete Nortman (left), president of EnergyCS, poses with a Toyota Prius converted into a plug-in hybrid. Greg Hanssen (kneeling right), president of sister company EDrive Systems, and Richard Nortman (standing right). -A plug-in hybrid Toyota Prius converted by EnergyCS gets up to 100 mpg by driving most of the time in all-electric mode. -A control screen to the left of the steering wheel helps the driver operate the plug-in hybrid for maximum efficiency. -In a plug-in hybrid the factory-installed battery pack is removed, replaced by a larger, more powerful one.