Hybrid-Car Tinkerers Scoff at No-Plug-In Rule

An idea whose time may never come.

 

I think that there would be a strong market for plug-in hybrids, but there will have to be a huge reduction in the cost of manufacturing the batteries. The ideal plug-in hybrid would be a short range commuter car. For normal day to day driving, the car could accomplish most of the trip on battery power. The ICE would be used for the occasional trips outside the electric only range, or if the driver didn't have a chance to fully charge the car. The biggest drawback with pure electric cars is the limited range and the lack of recharging stations.

The Prius or the Escape would make good test beds, mainly because they are the only full hybrids available. Unfortunately, their electric motors are not large enough for real world driving on electric power alone (unless someone wants to drive the stereotype of a hybrid). You'd also need a few more battery packs, and at 1-2 miles range and $2000 each, it would be quite an investment for the average commuter.

I wouldn't rule it out yet, we just won't see it available until the storage capacity of batteries is increased, and the cost greatly reduced.

 

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There already has been! Since the Prius was introduced in 1997 with NiMH batteries of about 46 Wh/kg and ~$2,000 per kWh, Lithium-Ion has progressed above 200 Wh/kg and below $400 per kWh.

AC-propulsion have shown that you can make a long range battery pack from stringing together lots of small 18650 LiIon batteries. (like AA-sized cells - the ones that go in cameras or laptops.)

The cost of these has been plummeting for years, mainly because of the scale of the market and competition between rival manufacturers. Today a single 8 Wh 18650 cell can be bought for about $2.50 - putting the current price of LiIon at about $300 per kilowatt-hour of electrical energy storage.

A Prius-based EV could manage about 4.5 miles per kWhr, and if we predict that the first plug-in hybrids will have at least 20 miles range, then you'd need 4.4 kWhr storage as a minimum, but more like 5 kWh so the batteries aren't filled or emptied completely (bad for the life of the battery).

So, in terms of the battery itself, you're only looking at a price premium of about $1,500 for the 20 miles EV-mode range (or $75 per extra mile on the options list!).

There would be no need to increase the size of the motor if used purely for "assist", and should have a similar effect on gas savings, so Toyota really could get away with installing only the battery, a charger and, of course, a hole for a plug!

 

i wonder what the savings really are especially in areas where oil fired plants are located. there is always energy losses when generating electricity.

here where none of the power is oil based (85% hydro, 5% coal 10% nuc) it might be a benefit, but most places use some oil.

i live in a conumdrum as you can see by the power delivery splits. here smack dab in the middle of hydro land where we sell power to over 60 million interstate customers and we still have to use coal for peak demands. sucks dont it? a decent solar energy project, highly localized on individual residences im sure could take care of that segment... even in the rainy pac northwest.

 

Pasted fom another thread:

Bob-
In reference to your statement about centralized power distribution efficiency; I'm not sure that is correct. The Well to wheel efficiency of the Toyota Prius is 32%.

Compare that to the average power plant with a thermal efficiency of 39%. The newest co-generation plants achieve around 50% and up to 55% at full capacity. Now figure in line losses in the neighborhood of 10%. That brings you to between 35% for the average and up to 50% for the best power plants. Next you must deduct 12% for charging losses. This leaves you with an average efficiency of 31.5% and a best case of 43%. Finally the Electric motor can be up to 90% efficient for a final result of 28.4% on average and a best case result of under 39%. Since we are on a national grid you will need to stick with the 28.4 % well to wheels efficiency of a current technology electric car.

The pollution issue also comes up short as the average power plant is much dirtier than the Toyota Prius due to old design and the high percentage of coal fired power plants.

All of these numbers are changing as new technologies come into play but this is my read for 2005. Since the Prius is already so efficient, the only reason I can see for grid charging one is to take advantage of cheap subsidized electricity. The Capex for this system is non-recoverable and the additional resources used are a net loss environmentally. There are also a dozen other arguments for using EVs such as off-peak charging and a few against but I'll leave it here for now.
*end of paste*

The issue of grid charging in areas with cleaner plants or hydro-electric is moot. Since we operate under a nationwide grid, any alternate demand on your clean power means increased demand on their dirty power. You must look at it from the perspective of the average thermal efficiency and the average pollution impact. The Prius already far excels over our power grid in both of those areas. Grid chargeable hybrids are a net loss for the environment even before the additional resources for creation of the batteries are figured. The only benefit is the ability to in effect run our cars on cheap coal. Sweet! Not!

 

I will add the one exception to this that I see. In about 5-8 years I expect nanotechnology to enable huge advances in battery and solar panel manufacturing. These advances will enable us to purchase stand alone solar systems. Then and only then can the additional resources and vehicle weight be justified. At that point, however; I expect fully electric vehicles to be more practicle than grid charged hybrids.

That is why I think that it is an idea whose time may never come.

 

Nanotech may very well give us better batteries and solar cells in a few years. It's also possible that fusion power will be available in the middle of this century. And lets not rule out transporter technology either, that would eliminate all of our transportation needs.

In the mean time, we need to take steps to reduce our dependance on oil as well as our impact on the environment. If we sit around waiting for the perfect solution, it might just end up being too late. Any advancement may ultimately result in a dead end, but we may also learn from the experience. Will everyone be driving hybrids in the future? Probably not, but there will be more on the road in the coming years. Will fuel cells be the answer? Probably not the ultimate one, and we still have to figure out how to create the hydrogen economically and store and distribute it safely. We can either take the philosophy of companies like GM and dismiss any advancement as a fad, or we can be like Toyota and take a chance and try to improve our current technologies.

 

I believe Toyota looked at grid charging and rejected it for the reasons that I stated. The Prius design is advanced enough to make grid charging one a step backwards. Toyota saw this and decided to move forwards. When EVs make more sense and it won't be long, Toyota will probably lead the way.

I really hope you don't think that I'm taking the philosophy of a company like GM. Quite the contrary, I think that many things that we think of as green are really like masturbation. They make us feel good but don't accomplish anything past that. We should experiment and develop new ideas in our pursuit of sustainability, without deluding ourselves into thinking that a grid chargeable hybrid is the holy graille, as some believe.

 

I would imagine that grid charging was primarily ruled out because of the cost of the batteries. The battery pack in the Prius is fine for a hybrid, but too small for extended EV excursions. If the power density can be vastly improved, and the cost reduced, then we will be closer to having practical electric cars. During the transition between hybrids and electrics, wouldn't it be logical to have high storage capacity hybrids? And wouldn't it also be logical to have the capability to grid charge at home or the office, assuming that electric utility costs make it economically attractive? I don't see this as a step back at all, but rather a step closer to full electric cars.

Lets look forward 10 years when I'm ready to replace my Prius. Lets say that Toyota has not fully abandoned hybrids, but is phasing them out and are now offering full electric cars. With great advancements in batteries, the full electrics have a range of 100 miles between charging, and they have reduced the charging time to 1 hour. On the other hand, the hybrids now have a range to 20 miles, and can be recharged in 4 hours. Lets also say that I work for a progressive company who offers charging stations at work. My commute is 25 miles, so if I get the EV model I don't even have to worry about recharging at work.

Would I buy the EV model? Not on your life. Maybe I would consider it if I were looking for a second car for commuting only. However, in 10 years you will not have as many recharging stations as you currently have gas stations, especially in rural areas. And even if every gas station installed a charging port, if I wanted to take a trip, I'd be stopping every hour and a half to recharge. And lets say that I misjudge my range and run out of power, I guess AAA can tow me to the closest recharging point, but I'd rather they just give me a couple of gallons of gas and let me be on my way.

EVs will absolutely be in our future, but between now and then, grid chargeable hybrids are a logical step in that direction. Maybe the ICE in a grid chargeable hybrid will rarely be used, but I would feel comfortable having it there as a backup.

 

In ten years EVs will have a range of 400-500 miles per charge and will recharge in an hour. You will be able to bump charge in a couple of minutes to get you down the road. Sanyo just released a battery that will enter the market in 2006 that can fully recharge in 6 minutes and charge to 80% in one minute. after 1000 charge cycles, the capacity is reduced 1%. 80% of it's capacity is available down to -40 degrees. The Tzero can already achieve over 300 miles on a charge without these new technology wonders. In ten years the propulsion unit of choice will be electric and in 20 years or less it will dominate. Maybe much less.

Until the efficiency and emissions of our nation's power plants is improved, this will not result in reduced emissions or more efficient use of energy. Our power plants are still dirty and inefficient. Relying on them for vehicle propulsion will be a step backwards.

I'm going to just respect your right to an opinion on this one. I could be wrong in my assumptions. We'll keep an eye on it in the coming years.

 

I'm glad to see the discussions. I would urge readers to look at our fact sheet at PRIUS+ and to read a new section we've added in response to many questionis that have come up: 4. How Much Cleaner than a Gasoline Car is a PHEV Charged from the Dirty (Coal) Grid?at CalCars-Vehicles. Finally, we've linked to this discussion at What People Are Saying about PHEVs, CalCars and PRIUS+ in a listing of discussion groups and blogs that have picked up the story (along with NYT, BizWeek and others to come).
--Felix

 

Hi Felix-
I went to the website and noticed a few things. First, the comparisons to conventional gas engines are misleading when we are trying to compare grid charging a Prius to an unmodified Prius. Second, none of the studies tested the Prius as far as I can tell. Third, after skimming through hundreds of pages of info referenced by and linked to this site, I can find no info on assumptions made in the testing. What are the grid emissions figures that were used. What vehicles were tested? How were the figures arrived at? I wasn't very convinced by the undocumented charts and graphs. Can you help me out here?

 

To follow up-

Felix-
I am excited about your progress and have been following it for some time. The mileage figures that you show fall well below the figures that I achieve. Is that because of the additional battery weight or are these supposed to represent an unmodified Prius.
Also, back to the issue of the grid figures. I see no mention of the certain types of emissions that are associated with burning coal. I understand that you probably a very busy man so I hope I'm not imposing too much in asking for a response to my concerns.

I will continue to watch your progress. It has been very interesting to watch your team identify and address the many problems in this endeavor. Good luck sir.

 

Yes, coal is bad.

But the great thing about plug-in hybrids is once you have them in place, you can change the whole electricity generation network to renewable sources without having to scrap, or even alter, an entire vehicle fleet.

But of most potential is the fact that as soon as you have a viable plug-in hybrid, then you don't even have to bother using a grid at all.

There's 20 miles daily range available from sunlight alone on the surface of the Prius, and way more than that with modest sized wind-turbines. This guy gets most of his daily commuting range from onboard solar and wind power:

http://www.solarvan.co.uk/ 8)

 

I'd like a better battery, that can give 5-10x as much assistance to the ICE as the current one does. That'd suit my needs for now.

Ummm, as long as I don't have to invest $6,000 to get it...