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Re: The “range–extended” EV considered

Posted: Fri Nov 18, 2011 8:25 am
by edatoakrun
From the OP:

“In fact, a true ICE ”range extender” for a BEV is not a bad Idea, It's just that current designs are all abysmal failures, from the point of energy efficiency and driver utility. Putting an ICE drivetrain in an EV, whether in series, parallel, or any other hybrid configuration, is not advisable, IMO. Invariably, you will get an overweight, overpriced, underperforming vehicle, like the Volt. It seems almost as ridiculous, to install an extremely expensive and heavy large battery pack (like the Tesla S long-range options) which is only occasionally required by the BEV driver.”

Well the concept of a trailer mounted range extender, posted, either a 30 kWh or larger hydrocarbon–fueled generator, or a large battery pack, more or less converts a BEV into either of the undesirable options above, a very large battery pack BEV, or a series hybrid ICEV. And I think you probably will require a trailer–mounted unit, if you either want a 30 kWh (series hybrid sized generator) or a larger-than 20 kWh add-on battery

The good news, or course, is that it’s only temporary, and you could theoretically set up rental networks, so that the (very?) high costs could be spread out over many users, and the efficiency penalties would only occur during the time of usage, Allowing cost and energy efficient BEV use at all other times.

But I believe these are among the least likely directions vehicle evolution will take. It is currently fairly cheap and simple just to rent a specialty vehicle for a particular task. Will range-extender trailer rentals ever prove superior to just renting the vehicle you require?

Maybe I should have premised the OP with the comments I have made many times on other threads. I believe BEVs are currently superior for the majority of consumers for the majority of their needs, and will soon largely replace ICEVs (including hybrids) and that BEVs’ market dominance will be constrained mainly by how rapidly the BEV charging infrastructure is established.

But the final stage in the evolution from ICEV to hybrid to BEV, the range-extended EV, in which the ICE is reduced to it’s vestigial state, as a small, cheap generator, intended only to do it’s dirty and inefficient work when absolutely necessary, to reduce the time and frequency of BEV recharge sessions on occasional longer trips, is now the missing link in the vehicle market, in this evolutionary path. And even after the ICE is no longer required at all, when the BEV charging network is established, and cheaper longer range batteries are available, I might have no problem at all ,still filling the combustion heater tank in my BEV up (with a relatively low polluting fossil fuel) every winter, to get heat much more efficiently than through the grid-to-battery-to resistance alternative.

I don’t get it. My LEAF is a great car, but if I lived 35 miles from town rather than 25, or if winter temperatures regularly fell into the teens, rather than the thirties (in Shasta County where I live, where there is currently virtually no charging infrastructure, and little prospect for rapid future development) I wouldn’t have bought it.

And if any manufacturer had brought a LEAF class twenty-something available kWh battery pack BEV to market, with a 4 kWh to 8 kWh range extender, with only a few hundred pound, and few thousand dollar cost, penalty (both realistic, IMO) I, like many LEAF buyers, probably would have chosen it, over my LEAF.

And I also think almost every Volt buyer, would have done so...

As well as many other car buyers, who chose ICEVs and hybrids.

Re: The “range–extended” EV considered

Posted: Fri Nov 18, 2011 8:42 am
by essaunders
For these micro turbines, what dies their claimed efficiency mean? What is comparable efficiency of other engines/generators (for comparison).

Re: The “range–extended” EV considered

Posted: Fri Nov 18, 2011 8:51 am
by edatoakrun
essaunders wrote:For these micro turbines, what dies their claimed efficiency mean? What is comparable efficiency of other engines/generators (for comparison).
As posted earlier:

http://www.microturbine.com/_docs/CAP11 ... der_LR.pdf" onclick="window.open(this.href);return false;

Somewhat better than most ICE, but about half as efficient as grid combined cycle natural gas, I believe.

Re: The “range–extended” EV considered

Posted: Fri Nov 18, 2011 7:44 pm
by N952JL
JRP3 wrote:
N952JL wrote:
I love the BEV, but the leaf needs to have 4x the range at the same price to become main stream.
Nah, double the range at $10K lower price would do it in my opinion, especially as fuel prices rise and people care more about getting to and from work and the store than the rarely taken road trip.
I disagree. Of course I am going by the 73 mile range for interstate @ 70mph just at one hrs. Double the range would just give me a 2 hr range before 30 min QC recharge to 80% for an addition hr and halve. That gives you about a 250 mile range in 4 hrs total time. That would just get me to Atlanta and back. Most of America is country, not city. There is more of America like Warner Robins than San Diego. If you want to go somewhere it takes time and distance. An honest interstate range of 300 miles would turn this car into the only car I would need. Less than 200 I need to rent or buy an ICE. An air travel isn't the answer as it a 180 mile round trip to the Airport area with no public or private charging anywhere near.

Re: The “range–extended” EV considered

Posted: Fri Nov 18, 2011 8:03 pm
by JRP3
Since most households have more than one vehicle most households are not really limited by an EV, especially if that EV has at least a 150 mile range. You're making the mistake of projecting your own situation onto the general public EV's don't need to have 300 mile range to go mainstream, they need to have enough range at a low enough price. Requiring enough range for a trip that might be taken once a year for most people is just not necessary, especially when there are other viable options, i.e, the second car or rental.

Re: The “range–extended” EV considered

Posted: Fri Nov 18, 2011 10:00 pm
by N952JL
JRP3 wrote:Since most households have more than one vehicle most households are not really limited by an EV, especially if that EV has at least a 150 mile range. You're making the mistake of projecting your own situation onto the general public EV's don't need to have 300 mile range to go mainstream, they need to have enough range at a low enough price. Requiring enough range for a trip that might be taken once a year for most people is just not necessary, especially when there are other viable options, i.e, the second car or rental.
I agree, I also have another ICE vehicle for the longer trips. But I thought the aim was to eliminate gas. I can't prove this, but for some reason I feel about 1.00 per gal of gas goes to fund the bad guys. And I really do not what any of my money going there. I would love to eliminate ICEs in total. We can't do that if we still need the ICE for the longer trips required by everyone who doesn't live in a city.

For example, you live in Savanna GA. You are forced to evacuate because of a storm. (Fl knows all about that). Where do you go? You go to Macon, 160 miles away.

Re: The “range–extended” EV considered

Posted: Sat Nov 19, 2011 6:23 am
by JRP3
About 20% of our oil comes from the "bad guys", so theoretically driving an EV about 85% of the time covers this. If we do most of our driving on electricity then home grown biofuels, become a real possibility to fill in for the rest when necessary. More to the original point though, EV's become mainstream long before your originally stated parameters are met, in my opinion.

Re: The “range–extended” EV considered

Posted: Sun Nov 20, 2011 11:40 am
by eHelmholtz
Ingineer wrote:Here's a cut-away drawing:

Image
Phil,
I just saw a cargo carrier at harbor freights that can hold 500lbs (it's $69.99 with a coupon). I wonder if you could use this to hold your generator setup and avoid having to have a dedicated trailer built; since it's aluminum, it should be lighter too. http://www.harborfreight.com/500-lb-cap ... erralID=NA" onclick="window.open(this.href);return false; Do you think it would work?

Re: The “range–extended” EV considered

Posted: Sun Nov 20, 2011 12:21 pm
by DrInnovation
I see lots of people tossing out long trips as an issue, some dismissing it as infrequent. Individual's of course vary but long trips are a real issue for the average American.

If you want to focus on reducing oil, or are mixing the desire for a new car with reducing costs and oil dependency then the BEV +ICE compared to an Range Extended EV REEV) +ICE take looking at real data. Your personal data is best and it is clearly very family dependent. But if one wants to talk main stream or average, that has been discussed on another thread (http://www.mynissanleaf.com/viewtopic.p ... &start=210" onclick="window.open(this.href);return false;)
where there is some data to address "average" American, look at http://www.bts.gov/publications/highlig" onclick="window.open(this.href);return false; ... on_03.html
The data is a mess but there are some useful tidbits you can get

The average American in that data takes 24 "long trips" trips per year, with a median distance of 194 miles. (Long trips are defined as the final destination > 50miles from home, so minimum 100m round trip).
So its not 1-2 times per year that the need 200 miles or more.. it is on average 12 times in the 200-2000 range and 12 times in the 100-200 range, with a total travel for long distance trips of about 7500 miles.

Which is better BEV+ICE vs REEV in terms of reducing gas usage depends on the the average of BEV+ICE verses a REEV. Since I don't know of the efficiency of any 3rd party range extender I cannot estimate it. But I will comment that some have posted here that a range-extender build into car is not efficient, without any data to support that view. If its a choice between buying a BEV to augment an existing average ICE, or buying an integrated EREV like the Volt (which gets 37mile per charge and 40mpg/hwy), then for the average data (commute <35 miles & ~24 long trips per year) BEV +32MPG ICE uses more gas than an EREV. Sure a family can do better; a BEV + Prius is better; A BEV + TDi is better. But if the choice is Buy a BEV and keep an average ICE, versus but a integrated EREV, the EREV may save more gas overall. YMMV and anyone considering the issue should model their projected usage.

What about the economics of an add on RE?
With a 25mpg ICE the 12 trips > 194 miles need about ~100 gallons of gas, which is < $400/year and it will be hard to justify an expensive range-extender. (Total long distance travel 7500 is about 300 gallons or < $1200 a year).
60% of families have second car, so the car is not and added cost, just gas. A rental ICE would obviously add more.
With respect to the total cost of covering one can argue if renting an ICE or a Range Extender makes more sense.
Renting a range extender might make sense if its efficient enough and the price < price of gas for the ICE. With a limited market for while that may be difficult to make cost effective.




If you are focused on minimizing cost this is totally moot as no new BEV or Range Extended EV (REEV) is the right choice. The right choice is used Prius or other high MPG car (because of the vehicle cost and rapid depreciation no new vehicle is a good financial investment), at least until used BEV or REEV are on the market and a decent price.

Re: The “range–extended” EV considered

Posted: Sun Nov 20, 2011 12:41 pm
by JRP3
I guess I don't know any average Americans since I don't know anyone who takes that many long trips in a year. Actually I do know one person who never seems to stop taking trips since she doesn't have to work and doesn't have any real hobbies, maybe she tips the averages.