Feb 27, 2008 (From the CalCars-News archive)
A few days ago, at "PHEVs Analyzed/Debated at Society of Auto Engineers Event" http://www.calcars.org/calcars-news/916.html we posted Jack Rosebro's report, "To PHEV or Not To PHEV (At Least in the Near-Term)." Here are two followups:
- another report on the event, in Motor Trend Magazine,
- a response by CalCars' Tech Lead Ron Gremban.
Motor Trend Editorial
To Make The Volt Affordable, GM Needs Toyota
Sharing battery technology is the key
By Kim Reynolds
When it comes to cars we'll be driving in the future, this much was clear at the 2008 Society of Automotive Engineers' Hybrid Symposia in San Diego last week: The future is far from clear.
There were some pretty sharp papers being delivered by such stars as Ford, Toyota, Honda, Nissan, GM and Chrysler at the event. But by far the most thought-provoking presentation was given by Dr. Menahem Anderman of Advanced Automotive Batteries. His paper, 'PHEV - A Step Forward or a Detour?' took a cold-eyed view of the debate over plug-in electric hybrid vehicles (PHEVs) based upon his interviews with over 40 companies, including all the major car manufacturers and battery makers.
Dr. Anderman's analysis shows that, for one thing, when we talk about hybrids, we're still effectively talking about one company - Toyota. With an 83% hybrid market share in 2007, Toyota is the 900-pound gorilla in the business of mass manufacturing and selling nickel-metal hydride batteries for automobiles. Moreover, the transition to lithium-ion batteries (as needed by GM for the Volt) will be based less on particular chemistries and technical details than their suitability for being mass manufactured in a reliable, economic fashion.
At present, and in the near future, Dr. Anderman doubts PHEVs will be very significant players, as the price of the battery packs - $4000 in the case of a PHEV-10 (one which can travel 10 miles on its battery alone) or $10,000 for a PHEV- 40 (the Volt, for instance) - is too high for them to be economically replaced during the vehicle's service life. At present, Dr. Anderman contends that the longevity of lithium-ion is just too sketchy.
The best way to restrain CO2 emissions, by Anderman's thinking, is to as quickly as possible promote present hybrid technology (like Toyota's) throughout the entire vehicle fleet, as it offers a bigger efficiency jump over conventional gasoline cars than PHEVs do above hybrids - and they're a ready-to-go technology. Then, as lithium ion battery life is verified, the PHEV battery price problem can be meaningfully hacked by riding on the back of the HEV big boys (basically, Toyota) as they transition to the new chemistry. In other words, Anderman says a vehicle like the Volt will be too expensive to sell in meaningful numbers until Toyota is ready to move from nickel-metal hydride to lithium-ion batteries and helps pull down the price of the battery technology.
As for hydrogen fuel cell technology - forget it; the money would be much better spent on PHEV development. Despite his frosty assessment of the PHEV situation, Anderman nevertheless sprinkled in a few intriguing tidbits regarding near-term lithium ion use - for instance, the technology's employment in an upcoming Mercedes-Benz S-Class hybrid and an unnamed Toyota/Lexus model. Hmmm.
From GM came a presentation from Peter Savagian, Engineering Director of Hybrid Powertrain Engineering. Title? 'Driving the Volt'. Unfortunately, it really wasn't about driving the Volt, but a recap of the rigorous analysis that's led them to the Volt's radical powertrain architecture. Consider Mr. Savagian's facts: by 2020 there will be more than 180,000,000 additional cars on the world's roads. And by 2030, we're going to need 70% more energy than we are so hard-pressed to crank-out now.
GM's energy answer is to diversify our transportation energy sources beyond our current 96% dependence on oil. And GM's Hail-Mary vehicular answer is the Volt's E-Flex platform which, they go to great pains to explain, is an 'extended-range electric vehicle', not a 'plug-in hybrid'. Whatever, you say? Well, there's actually a big difference between the two. Operationally, a PHEV can be rigged to function in two ways - either in blended mode where it's frequently sipping from its battery, or in initial EV mode, where its battery is relied on for a modest number of miles before the engine gets involved and the sipping scenario starts. EREVs employ really big batteries and moreover, stretch their battery-only reliance out to the maximum of miles before a motor-generator intercedes full-bore. With EREVs, most drivers would rarely see a gas station. PHEV drivers would visit them occasionally.
Gary Oshnock, of Chrysler LLC's Environmental and Energy Planning offered some interesting regulatory as well as technical insights. He began with a run-through of 2007's dizzying string of legislative events: in January was the President's '20 in 10' challenge to reduce gasoline consumption by 20% in 10 years. In April, the Supreme Court ruled that CO2 is a pollutant. In May came a Presidential executive order to "ensure effective coordination between agencies regulating vehicle greenhouse gases". And, of course, on December 19th came the Energy Independence and Security Act of 2007 - the now famous Energy Bill, which requires by 2020 an industry average of 35 mpg, and after that, the maximum feasible mpg through 2030. On the same day (just a coincidence, mind you) the EPA denied California its waiver needed to implement AB1493 which would have mandated a much stiffer 43.5 mpg average for cars and light trucks by 2016. What a year.
He also offered a few interesting observations on fuel efficiency. For instance, on a ton-mpg basis, fuel efficiency has actually been climbing by a steady 1.2 % per year for the last 22 years. Trouble is, our liking for added creature comforts, structural stiffness, and crash-safety features - all of which add weight - has pretty much nixed any actual fuel efficiency gains. What does 35 mpg by 2020 translate into on a year-by-year basis? 3.5% per year. In other words, the new CAF standards are going to require three times the recent historical annual rate of efficiency improvement - and notably, that's after you factor-in any concomitant weight gain, not before. We may be using sun-dials to measure zero-to-sixties before this is done.
Sherif Marakby, Ford Sustainable Mobility Technology Chief Engineer, spoke about the upcoming Ford Fusion and Mercury Milan Hybrids. Basically, these two are slated to get the 2009 Escape and Mountaineer's upgraded hybrid powertrain which is distinguished by greater displacement (2.3 liters to 2.5), quieter operation, smoother transition from electric to mixed mode, greater electric-only operation during city driving, twice the frequency of engine stop/starts, fuel shut off during deceleration, and better regenerative braking feel. All told, the Fusion and Milan Hybrids will offer over 60% better city mileage than a comparable, conventional-tech, four-cylinder engine.
Tom Turrentine of UC Davis's PHEV Research Center argued that car buyers don't really calculate the payback periods of advanced technology offered by their improved fuel economy; lots and lots of other reasons come first. And maybe he's right. The initial buyers of hybrids were by in large 'greens'; they were followed by tech geeks, then folks concerned about oil security, and now good old fashioned cheapskates who just hate to waste money at the gas pump. Heaven knows there's a lot of those. It was also stressed that clear and instructive info displays which readily portray the vehicle's energy use have been very important to the Prius's good results, and might be even more significant for PHEV owners.
Dr. Mark Duvall of the Electric Power Research Institute (EPRI) noted that construction of coal-fired power plants is currently at a standstill in the United States for fear of significant carbon penalties and restrictions looming in the near future. Nonetheless, he dismissed the sometimes-mentioned fear that a nation of PHEV driver's would swamp the grid's capabilities. At most, the increased demand would be something like 12%, and of course, the vast majority of the charging would take place at night, when the utilities are begging for customers. An interesting sidebar to this had to do with what the industry calls the 'Smart Grid'. Basically, there's a battle going on over the design and the operational protocol of future EV and PHEV plugs. What the utility industry would dearly like is a means by which, when you plug-in, information about your daily use is first transmitted to the utility (say, the car needs to be ready to go at 6:30 AM), and then your specific charging period would be intelligently scheduled during the night instead of everybody trying to simultaneously plug in at 12:01 AM.
Other Hybrid Symposia highlights included a nice review of Nissan's progress, by Toshio Hirota, wherein the Altima Hybrid received due attention. Honda offered two talks, one on the mathematical modeling of electric motor controls which next to no one understood, the other on a peculiar prototype which captures the heat normally lost through the exhaust system to drive a small Rankine-cycle steam engine instead. I guess this qualifies as a hybrid. And of personal interest is the progress of an updated SAE standard for testing PHEVs - J1711 for those of you keeping score at home. Dr. Anderman's reservations not withstanding, we're going to want to have our ducks in a row when GM finally delivers on the Volt.
Posted by: Ron Gremban, CalCars' Tech Lead | Feb 25, 2008 9:19:05 PM http://www.greencarcongress.com/2008/02/to-phev-or-not.html#more
This splash of cold water by Dr. Anderman appears to be the main media take-out from the recent SAE Hybrid Symposium, which included many other discussions and information, so I'll address it here:
1. Dr. Anderman accurately claimed that our standard U.S. measure of mpg overstates the value of additional fuel savings to already-thrifty vehicles. For example, the savings from an 80mpg vehicle over that of a 40mpg vehicle (40mpg difference and 1/80 gallon per mile savings) is less than that of a 40mpg vehicle over that of a 20mpg one (20mpg difference but 1/40 gallon per mile savings). He then went on to use this point and various mpg figures to indicate that there is a bigger difference between ICE and hybrid fuel usage than between that of hybrids and PHEVs, and that hybridization therefore has a higher incremental value than plug-in technology.
2. Dr. Anderman then pointed out that, due to their newness, there is some uncertainty in the longevity of Li-ion batteries in automotive applications. However, he immediately took that to the overblown conclusion that the auto manufacturers would need to include the cost of a warranty battery replacement -- at today's, not lower future, prices -- in their cost calculations for production PHEVs.
3. As a result of these two assertions, Dr. Anderman placed PHEVs on a graph where their incremental value is smaller than that of hybrids but their incremental costs are much higher. From that, he asserted that promoting further penetration of hybrids into new vehicle fleets would do more to eventually bring about PHEVs than promoting the production of of PHEVs themselves at this time.
Let's look at Dr. Anderman's assertions:
1. "Hybridization has a higher incremental value than PHEV technology." Using fuel consumption rather than mpg figures to avoid Dr. Anderman's overstatement issue, strong hybrids have generally been able to reduce fuel consumption by 15-40%. Solid figures are hard to obtain because performance also varies between hybrid and non-hybrid versions of vehicles that have both. Let's use 30% as a rule of thumb. PHEVs don't improve fuel economy so much as they displace liquid fuels, by 30-90% in normal daily driving. Of course this 30-90% is of the remaining 70% of ICE consumption still occurring after hybridization, so it amounts to 21-63% of the original consumption, potentially a significantly larger cut than for mere hybridization.
Of course, CO2 emissions are not cut by as much, as electricity is now consumed, too -- giving Dr. Anderman the chance to say the result is less significant. But the switch to electricity gives us a chance for future CO2 emissions decreases that continued complete reliance on liquid fuels cannot, as well as flexibility not provided by ordinary hybrids in the case that we really are seeing peak oil (see below). Also, two things that no one has yet figured into ICE and hybrid CO2 emissions figures are that real-world all-weather mileage is significantly lower than EPA estimates (2008 sticker figures are now better compensated for this, but the automaker CAFE requrements are NOT!), and well-to-tank emissions are set to spike with increased use (already begun) of both harder-to-pump deep, low-grade oil and far more carbon-intensive substitutes from tar sand and even coal.
Of course, Dr. Anderman might say that the answer is then a combination of hybrids and biofuels. I would agree that at little more than $100/vehicle added cost, there is no excuse for all vehicles manufactured today NOT being flex-fuel -- capable of running on biofuels as well as gasoline or Diesel. However, two major studies (one California state and one national) have concluded that the biomass available without cutting into world food production or cutting down forests, even with expected advances in cellulosic technology, is capable of supplying no more than 1/3 of our current transportation energy, without even allowing for growth of the transportation sector. Therefore, I would submit that the value of the leap from hybrid to PHEV is significantly LARGER, not smaller, than that from ICE to hybrid.
2. "Auto manufacturers would need to include the cost of a warranty battery replacement, at today's prices, in their cost calculations for PHEVs." In spite of their newness, GM has stated that there are Li-ion cells that meet their criteria, which means that must have passed laboratory lifetime tests indicating an expected lifetime matching or exceeding the expected life of a PHEV. Additionally, NiMH batteries, now used in all hybrids, have a strong track record in EVs and are fully capable of powering PHEVs with up to 20 miles EV range, if not more. For now, battery prices are high -- e.g. $250 per mile of EV range -- but Li-ion materials costs are low (and estimates of world lithium reserves are enough for 2.5 billion PHEVs), so there is plenty of room for eventual cost reductions of a factor of four with automotive-scale mass production. Even if auto manufacturers did have to replace some -- even all -- of the batteries in the first year or two of PHEV production, the cost of the replacement packs would no doubt be dramatically lower by the time the replacements were actually needed, and many risk-sharing options and incentives have been proposed to displace much of the early risks from the automakers.
On the other side of the cost equation,
3. "The incremental value of PHEVs is smaller than that of hybrids but their incremental costs are much higher." To hybridize a vehicle's powertrain requires a large amount of change, mechanical as well as electrical and electronic. Large tooling is needed to produce new mechanical powertrain components like motor/generators, power-split transmissions, etc. And achieving 25-40% fuel economy improvements also requires major redesign and re-tuning of the ICE itself (check out what Toyota has done to improve the Prius' Atkinson-Miller engine's efficiency over that of an ordinary Otto-cycle ICE). Once the hybrid's electric propulsion system is already in place, the changes required to turn it into a PHEV are very minor, as proven by all the aftermarket hybrid conversions that have proliferated since we at CalCars first converted my Prius into a PHEV. The only big additional expense is that of the larger battery.
The other side of the cost equation is fuel savings. Electricity costs the equivalent of $1.00 per gallon of gasoline or less. All return-on-investment (ROI) calculations have been done with today's $3.00, or yesterday's much cheaper, gasoline. Recent gasoline pricing predictions have been consistently low, world production is now near world capacity, new oil discovery has for years been 1/4 the rate of extraction, and China and India's auto ownership is growing exponentially. The probability is that the cost equation is going to continue changing rapidly and consistently in PHEVs' favor.
Dr. Anderman also relies on two more unstated assumptions:
- "Advances in battery production and pricing cannot be hurried-up." The availability of cells that can do the PHEV job -- which GM has announced are available -- means that the biggest issues are further testing, integration into packs, and high volume production. Although there are limitations to how fast these things can proceed, rapid ramp-up of high volume, low cost production is amazingly amenable to infusions of large investment. With the right incentives, it could happen far faster than the multi-decade process that Dr. Anderman predicts.
- "The changeover from ICE to hybrid, then PHEV powertrains will happen in a business-as-usual way, as it has up to now." IPCC scientists are indicating that we need to cut worldwide CO2 emissions by 50% by 2020 and 80% by 2050 to avoid the worst consequences of climate change and/or a tipping point that cannot be reversed; it is possible that we have already hit peak oil; and China and India's economies are expanding exponentially. At some point soon, when we see a quantum leap environmental and economic urgency, not only will new vehicles quickly need to use dramatically less fossil fuel, especially since they will be burning fuel for at least a decade after manufacture, but we will need to rapidly begin doing something about the 820 million vehicles already on the world's roads.
Since PHEVs do have significant added value beyond that of ordinary hybrids, and because the main extra cost is only for a larger battery, immediate promotion and incentivization of of PHEVs does make sense, as it will further speed up the mass production of PHEV batteries, which require different tuning, testing, and field experience from those for non-plug-in hybrids!
[Second posting]: After all that I forgot to mention that immediate promotion and incentivization of PHEVs is also needed to begin the education of the public to the myriad social and personal values of automotive electrification. Most of us don't fully "get it" until we have actually experienced driving a PHEV. I myself was surprised and excited by my first experience, and I have been a builder of and advocate for electric vehicles since 1968!