You’ve no doubt already heard plenty of buzz about hybrid gasoline-electric cars that boost mileage to the mid-40s. An interesting feature story highlights some people pushing the hybrid envelope so that their cars get up to 250 mpg.
Current hybrids such as Toyota’s popular Prius are equipped with an electric motor and special battery packs that charge when the car brakes and accelerates. Stored battery power drives the car in normal running. Whenever battery power runs low or during hard acceleration, as when passing, the relatively small gasoline engine takes over.
Some backyard mechanics have modified their hybrids into 250 mpg. wonder cars by adding extra batteries charged solely by home AC power. Meaning, they plug the vehicle into a wall outlet overnight or when it won’t be used for a few hours. That stored-only electricity provides much of the power for the first while of the next excursion.
When the stored-only batteries poop out, the vehicle reverts to normal hybrid operation with the car’s stock battery pack and gas engine working in tandem.
One part of the generally well-done story leaves us scratching our head. Early on we’re told one hybrid developer has “a stack of 18 brick-sized batteries” in his trunk. Shortly, we’re also told:
The extra batteries let Gremban drive for 20 miles with a 50-50 mix of gas and electricity. Even after the car runs out of power from the batteries and switches to the standard hybrid mode, it gets the typical Prius fuel efficiency of around 45 mpg. As long as Gremban doesn’t drive too far in a day, he says, he gets 80 mpg.
This is where it gets hairy. Unless Gremban has figured out some way to abridge physics the rest of us live with, his car should suffer a noticeable mileage penalty for lugging around the weight of those 18 extra batteries, plus whatever cabling and other hardware they require. We expect that penalty would be hard to justify for someone who commutes 50 miles or more each way five days a week.
Or is there something we’re just not getting?
Not so fast: While we’re on the intriguing subject of hybrids — made all the more intriguing by the current bleed-us-white price of midgrade unleaded — we have a couple of questions about the stock technology being sold by Toyota, Honda and Ford.
First, given the added initial cost of a hybrid, which we’ve seen referred to variously as $3,500 to as high as $9,000, what happens to accumulated fuel savings after three years and six years, when the battery pack needs replacing?
Second, in cold northern climates, shouldn’t prospective buyers be warned they’re likely to go months at a stretch getting little if any benefit from the extra electrical paraphernalia they’re hauling around? The simple fact is that battery power declines sharply as temperatures near the freezing point. Below freezing they’re really slugs.
Although we’ve seen a bunch of mostly enthusiastic articles about hybrids, we’ve yet to see either of these issues addressed satisfactorily.
Here’s how Gremban gets his apparent 80 mpg: with the batteries he charges from his home outlet, he’s using eneergy that he gets from the power company (said power company likely burning fossil fuels to produce the electricity) but “charging it” (if you will) to the credit of the gasoline account in his hybrid. On a global scale, it’s not a real increase in fuel savings. It’s the same accounting that hydrogen-fuel advocates use in promoting “pure and clean” hydrogen — it is, but producing it typically burns more fossil fuels to produce it than would have been consumed for the energy it releases.
I understand what you’re saying, Jeff, but apparently I wasn’t clear enough in the post. Where I have a problem is with this reference to consumption rate: “Even after the car runs out of power from the batteries and switches to the standard hybrid mode, it gets the typical Prius fuel efficiency of around 45 mpg.”
So what they’re saying is, after the power in the 18 extra batteries runs out, the car goes back to getting the same mileage as any other Prius. I’m asking how that can be, since unlike stock Priuses, this guy is hauling around all that extra weight.
SW, if he is on flat ground and only accelerates to cruising
speed, the extra weight might not subtract much from his
mileage. In stop and go traffic, or on hills, the weight penalty
might negate the added “gas mileage” his batteries give him.
Hold your breath — RSF and I can pretty much agree! For the consumption number, as stated, being unchanged I would imagine several contributors.
One is that he’s probably added maybe 200 lbs of batteries. The Prius, however, weighs just under 3,000 lbs., so he’s only increased the weight by
6 2/3 %. On flat ground there would be some increased rolling resistance, but this would be negligible. Air resistance would be unchanged.
In matters of fuel economy, steady speed is your friend. Acceleration is the enemy.
300+mpg Super-hybrid rolling out this fall
The first “I†car X’s will be rolling off the assembly line within the next 60-90 days. Not only do we expect to be in full production within the next six months but we expect to have 185 thousand units produced 18 months after full production has been realized.
Our design team has engine designs that will allow trucks that are diesels now, and carry products throughout our nation to meet and exceed 100+ MPG with no loss in performance.
This composite side by side 2 seater is a fly by wire Super Hybrid. Because the relationship to the gas to electric conversion is rated by hours per gallon, the faster it goes the further it goes. If you are traveling at 60 mph the “I†car will get 5 hours on a gallon of gas, if gas were the only source of energy.
The Superhybrid “I†car X also has a solar array, wind generators and inductive breaking. Once traveling at Highway speeds the Twin wind turbines are generating energy as is (during a sunny day) the solar array. Every time you use the breaks you generate electricity.
Most Hybrid cars of today are very heavy and use one enormous and expensive battery. The “I†car Superhybrid is very light and uses many Li.Ion batteries (the same as in your laptop) that as they fail the onboard sensors detect and exclude that cells participation in the charging process.
If you work within 5 miles of where you live, you may never need to buy fuel. Leaving the “I†car under the sun all day will charge the Li. Ion batteries. If you park in a Metal Halide or Halogen lit parking structure your batteries will charge.
The “I†car has a on board redundant intelligence, that allows you to interface with the car using your PDA. Fly by wire, on board charging control, personal configurations, and GPS are just a few of the smart features.
In response to Jeff. The pennys an hour it takes to recharge the car FAR FAR outweighs the cost of the gas. Besides What if he lives near a nuclear plant eh? Then you coal issue goes out the window. Besides he would waste more money and more polution by running a lightbulb than charging his car. Think for a second.
Monetary cost, yes; thermodynamic cost, no. Every time you convert one form of fuel to another, it costs in thermodynamic losses: heat and by products, typically carbon products if petroleum products are involved.
Car engines consume a certain amount of energy to perform a certain amount of work — moving the car. As a baseline, count the amount of carbon-based fuel it takes to go a fixed distance on a certain course. Now, replace the carbon-based fuel with electricity generated with carbon-based fuel and re-run the course. Count how much carbon-based fuel was expended to create the electricity that ran the car and, because of the thermodynamics of the process, the total amount of fuel consumed will be greater in the second instance than in the first.
Use nuclear power instead of fossil fuels and replace the carbon waste with thermal and radioactive waste, which may or may not be a more acceptable cost to you. (However, the total heat generated will still be greater than just running the car.)
Thermodynamics is unavoidable and always gets its cut. I have thought about it for most of my career, in fact; others have thought about it for going on two centuries.
And if you really think that a 100-watt light bulb consumes enough power to run an automobile, well, I’ve got a perpetual-motion machine here that you might like to invest in. Power too cheap to meter!
I’m with Jeff. The Laws of Thermodynamics can’t be repealed; but we can live with them.
The primary incentive for going hybrid is to minimize or eliminate our dependence on foreign oil and to enhance prospects for US energy independence. The economic benefits derive from avoiding entanglements such as we currently suffer in the Mid-East as well as for improving our balance of trade. The need to reduce emissions as identify with the cause(s) of Global Warming has become readily apparent. A renewed pursuit of the nuclear power option is in order. The theoretical projections of “excess deaths” due to increased exposure to radiation and the costs of handling waste products pale when compared to costs in terms of life and dollars due to foreign imbroglios caused by dependence on foreign oil.
The techno-economic and possible consumer cost tradeoffs due to battery technology deficiencies must be recognized; but can be overcome by procedural actions and technology upgrades Just recently there has been an announcement of a scheme for interfacing large storage capacitor “buffers for improving battery performance and life.
Hybrid cars can and will be the mainstay of our economic future
I’ve about decided our best option for powering vehicles and maybe other things is hydrogen technology. I think if the U.S. were to commit to a development program to make hydrogen commercially available and affordable with a project similar to the Manhattan Project to develop the A-bomb, we could get it done within a decade.
Yes, this would cost a lot. But the cost would be tame compared to having to fight wars in the Mideast repeatedly. We would be freed of dependence on OPEC, from having to protect sea lanes so oil supplies won’t be interrupted and many other things. In the long run, the cost of developing hydrogen technology would be money well spent.
Thanks for commenting on this very old but still timely post, Alessio.
Yeah S.W, Hydrogen has been looked at for some time as the means for resolving the uncertainties of our energy future; but the technology is not quite there as yet.
We still need to find a cost effective means for extracting hydrogen from water. Thermodynamics limitatations call for expending much more energy to produce hydrogen than we can get from it. Still, we’ve been willing to pay the thermodynamic penalty for producing electricity. Relying on Natural Gas as the primary source of hydrogen can be only a stop-gap measure. Thermochemical and Electrochemical water-splitting technologies offer some promise via ties to solar and/ or nuclear -derived heat sources.
We need to find at least a two-fold improvement in weight-efficiency for on-board storage of hydrogen fuel Current schemes for ultra-high pressure storage in advanced composite material gas cylinders should make folks nervous.
Yet another barrier to the commercialization of hydrogen-fueled traction power is the continuing reliance on precious metals to serve as fuel cell electrode catalysts. We need to to continue to advance the state-of-the-art of electro-catalysis for fuel cells in order to avoid the cost and institutional impacts of platinum now required for reliable and effective fuel cell performance
Yes, Hydrogen offers interesting possibilities; but for the far term. For the near term, The focus on performance upgrades of hybrid cars makes a lot of sense. Also hybrids can work with liquid or gaseous fuels be they gasoline or alcohols or natural gas. Barriers to market acceptance will be surmounted , inevitably,for economic, environmental and diplomatic reasons. And we can’t afford to wait.
And who is to say that we can’t have a battery-Fuel cell hybrid thus reducing the amount of hydrogen required for on-board storage?
Another informative and interesting comment, Alessio. You must be an engineer.
I stand by my suggestion for a top-national-priority , all-out program to develop hydrogen technology within a decade. Maybe concurrently we could pursue reasonably clean coal technology and/or oil shale technology. With oil as high as it is now, the economics should be reasonable.
Re: battery-powered hybrids in the short term, I have reservations about the added weight and replacement cost of batteries.
Yep I’m guilty. Working out of a National Lab, I served as Field Manager for the DoE R&D Program on Chemical/Hydrogen Energy Systems from 1978-88 until I retired. As I’ve said, Hydrogen offers interesting possibilities; but the technology is not quite ready for addressing near term fuel needs of the automotive transportation sector. You’re right about the tradeoffs required for battery hybrids; but still, they can make a difference with strong promotion for market acceptance.
Let me be clear, we’re in agreement on the need for a realistic, top National Priority energy R&D program looking at alternative fuels, including cleaned up geo-pressured natural gas while revitalizing the clean coal and nuclear power options.
All of this needs to be conducted within the framework of a no-nonsense Energy Policy focusing on energy independence. In my view such a program must be run on an emergency basis a la Manhattan Project with strong industrial participation.
Not high-tech, admittedly, but I think we could make a dent in oil imports with two relatively modest conservation measures:
1, The (next) president should call on businesses, to the greatest extent possible, to shutter drive-up windows for the duration, and call on consumers to be good sports, park and go inside for their burgers or to make bank deposits. Obvious exceptions would be businesses that only have a drive-up window and ones located where parking is extremely limited.
2, Vigorously encourage telecommuting using the bully pulpit and possibly limited-time tax incentives.
If we could score a 10 percent additional drop in consumption, beyond people’s cutbacks due to high prices, we might make a bunch of speculators nervous enough to start selling a whole lot of futures contracts. If that snowballs, we could see $2-2.25 regular by the end of the year.
Just a reminder for whomever should be concerned:
The Opec Embargo of the 1970′s failed subsequent to the display of international unanimity in pursuit of energy alternatives led by a commitment to nuclear power. The return to normalcy in the 1980′s resulted in a false sense of security and the complacency that has led to where we are now.
Another excellent point, Alessio, and we should all be concerned  ultimately, even the fat cats profiteering from the hardship of millions of their fellow Americans.
I think international unanimity won’t come until a new and much better U.S. administration has done a lot fence mending.
Looks like the hybrid is carrying the extra weight equal to that as another person. All cars have been factored that amount of extra weight. There probably is not much difference. My truck gets the same mileage with a load or no load.