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Grex > Agora46 > #161: Grid-connected electric and hybrid cars: insurance for the power grid | |
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| 15 new of 39 responses total. |
scott
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response 25 of 39:
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Aug 19 13:25 UTC 2003 |
(doubtless I'll be asked to RTFA after this question, but...)
Russ, weren't you dissing the usefulness of some electric vehicle a while
back, based on the issue of charge/discharge cycles wearing down the battery?
I vaguely recall somebody talking about a hilly commute to work...
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russ
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response 26 of 39:
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Aug 19 23:26 UTC 2003 |
Re #25:
>... weren't you dissing the usefulness of some electric vehicle a while
>back, based on the issue of charge/discharge cycles wearing down the battery?
Possibly. Not every vehicle is good for everything, and it's in my
character to say that something isn't appropriate for a given purpose.
HOWEVER, battery-discharge issues are largely mooted by hybrid
vehicles, and IIRC the small variations in charge used by the grid
stabilization scheme don't appear to decrease battery life much even
for lead-acid batteries. If you could get paid more than the wear on
the battery costs, you'd come out ahead. Just in case I'm getting it
wrong, see my source for this:
http://www.acpropulsion.com/Veh_Grid_Power/V2G%20Final%20Report%20R5.pdf
Incidentally, the problem of battery damage by deep discharges goes
down as the battery capacity goes up, and it appears that a relatively
small and light lithium-ion battery would hold more than enough energy
to power a vehicle for most people's daily driving.
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russ
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response 27 of 39:
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Aug 24 20:24 UTC 2003 |
I've had a chance to re-read the final report (finally!), and I'd like
to quote from it to give everyone an idea of what's possible:
2.3 Results
Results showed that wireless data transmission times were within
ISO system requirements, and that the daily energy throughput
through the battery pack while performing regulation is of the
same magnitude as that from typical daily driving. Battery
heating during the test periods was negligible. The long term
effects on battery life were beyond the scope of the study;
however, it was noted that battery energy capacity increased by
about 10 percent during the course of the testing. The monetary
value created by these services varies with the market price for
grid ancillary services. A sample vehicle usage profile was
developed, with on average 22.6 hours of grid connect time every
day. The value of grid regulation was determined for this usage
profile based on regulation pricing from sample weeks in
December 201, April 202, and July 2002. The annualized gross
value created with 80-Amp grid connections available at home and
at work ranged from a low of $3,038 for December 2001 to a high
of $5,038 for July 2002. The results support the ZEV program
goals by demonstrating the feasibility of vehicle-based grid
services or V2G.
Note well the various benefits:
1.) Negligible battery heating (implies very high efficiency).
2.) Battery capacity increased (implies long life).
3.) Gross value created was up to $420/month, and never below
$250/month. (That's based on market prices for regulation
services, if you read the rest of the paper.)
When you consider that a complete lead-acid battery pack for an electric
car is only about $2500, getting that much extra value out of the
batteries ought to get everyone's attention. The car could go a long
way toward paying for itself.
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russ
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response 28 of 39:
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Sep 20 04:12 UTC 2003 |
People who have any interest in the possibilities of electric cars
should take a look at this article:
http://www.nytimes.com/2003/09/19/automobiles/19ELEC.html
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drew
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response 29 of 39:
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Sep 20 19:50 UTC 2003 |
I like the progress so far - and it would go really well with an
Amick-style wind foil. Could have virtually infinite range that way, since
it regenerative-brakes.
But must these things be so expensive? The quoted price would buy 44000
gallons of gasoline at $5/gallon. Is there a way to get such capability a
couple of orders of magnitude cheaper?
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russ
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response 30 of 39:
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Sep 21 00:11 UTC 2003 |
I suppose you could make the car cheaper if you didn't build it
by hand. I hear that this tends to drive up the price a bit.
More seriously, I'm told that Li-ion cells are now available for
roughly $1/amp-hour. At a nominal voltage of 3.6 volts, a string
of 75 cells at 200 AH would hold 54 KWH and cost $15,000. That
would be enough to go a couple hundred miles in an efficient car.
The price is bound to keep coming down with time.
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gull
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response 31 of 39:
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Sep 23 14:26 UTC 2003 |
Do NYT user IDs expire if you don't use them or something? I don't go
there much, but every time I do none of the ones I thought I'd created
work. I'm getting sick of creating a new one every time someone posts
an article.
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klg
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response 32 of 39:
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Sep 23 16:14 UTC 2003 |
We believe they do.
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rcurl
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response 33 of 39:
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Sep 23 18:27 UTC 2003 |
I've given up on the NYT website because of this. They are just losing
an audience if others also find this onerous.
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mcnally
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response 34 of 39:
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Sep 23 19:01 UTC 2003 |
re #31: I've got an infrequently used one that I've been using
occasionally for nearly five years now and another one that I use
for daily browsing. Despite going months between uses the
infrequently used one has never expired.
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scott
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response 35 of 39:
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Sep 23 19:17 UTC 2003 |
Probably it's the NYT login cookie(s) getting expired on in/by your browser.
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other
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response 36 of 39:
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Sep 23 20:01 UTC 2003 |
I keep my cookie file locked (thanks, rcurl) with the nyt cookie and one
or two others in it. All others disappear as soon as the browser quits.
I've never had to re-enter my nyt login.
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other
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response 37 of 39:
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Sep 23 20:02 UTC 2003 |
(IIRC, one of the others is a Doubleclick opt-out cookie.)
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mary
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response 38 of 39:
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Sep 23 20:12 UTC 2003 |
There must be something different about the settings
of those having problems. I'm using my original NYT account
opened at least a couple years ago and it's never burped
on my login.
I use Safari and have cookies enabled but only for sites
I navigate to and accept.
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gull
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response 39 of 39:
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Sep 24 01:01 UTC 2003 |
Re #33: I doubt that bothers them. It's not like they make any money
off the website.
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