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Old 11-05-2010, 08:29 PM   #101
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I don't have access to SAE libraries. Mucho Drachma for subscription. From a MIT discussion:

3.5 The Internal combustion engine (Otto Cycle)

The quantity is called the compression ratio. In terms of compression ratio, the efficiency of an ideal Otto cycle is:



Figure 3.11: Ideal Otto cycle thermal efficiency

The ideal Otto cycle efficiency is shown as a function of the compression ratio in Figure 3.11. As the compression ratio, , increases, increases, but so does . If is too high, the mixture will ignite without a spark (at the wrong location in the cycle).


Ideal engines at 9:1 compression have thermal efficiencies of better than 50 %. I realize in practice theory is a bit far flung.
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Old 11-05-2010, 08:35 PM   #102
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OK. Can't argue with that graph.
Well, I'll split the difference with you. The idling/standby losses (17.2% aren't technically a measure of the engine's thermal efficiency, they are more a function of the way the car is driven (very low if doing all-day interstate travel, etc)
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They do not discuss how to heat a vehicle in January in Manitoba using battery power. While the the gasoline engine's waste heat takes care of the problem nicely for 5+ months of the year.
That's going to be an issue. The Nissan Leaf plans to use a standard electric resistance heater, which is going to use a lot of juice. Burning fuel in a small catalytic heater (with outside air, no recirculation) would help a lot, but the refueling hassle and possible safety issues probably make this impractical.
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Old 11-05-2010, 08:35 PM   #103
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...
There are tradeoffs, in my relatively mild western PA, compared to say the Dakotas, I would not want to deal with an electric vehicle year around. Could be an OK toy in the summer. On second thought, maybe not at all, In January the electric rates will be de-regulated. Kiss byby to 10 cents per KWH.
Winter is one of the bigger considerations when considering an EV.
From what I have heard from other winter drivers, a 35% to 45% reduction in range.
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Old 11-05-2010, 11:49 PM   #104
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OK thanks Nords. I was just trying to get a handle on how Zathras was calculating that 1.5 cents per mile number he gave. That's a very attractive number if it doesn't have strings attached (like an assumption your system is already fully amortized). If it could be readily duplicated by the average home owner/EV owner, I'm sure it would be a very popular arrangement where conditions would allow it.
It's a niche... and when you're paying 22-25 cents/KWHr to import the oil across 2500+ miles, it's a popular niche. But solar & wind construction have exploded around here in the last 12 months.

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Nords,
How many kwh did your solar panels generate in the past 12 months? And what is the total capacity of your panels?
In the last 12 months we've generated 3168 KWHrs, from a low of 230 in February (28-day month) to a high of 298 in August. We have 45 panels on the roof for a total of about 3300 watts on a 3000-watt inverter. Most of the panels are 1990s vintage of 55-60 watts and 16 of them are 2005-model factory seconds of 115 watts. It's the computer equivalent of a rooftop full of 486s and Pentium PCs.

The technology has moved ahead smartly in the last five years with higher conversion efficiency and higher power density. Inverters are a lot better. Today you could have the same rating and generate more power from about 10 panels taking up about 60% of the roof space used by our current system-- admittedly at a considerably higher price than we got from Craigslist, eBay, and DIY.

I've calculated that we'd need another 3-4 kilowatts to recharge an EV. We'd either need to build a pergola on the south side of the house and roof it with the aforementioned 10-14 panels (plus a second inverter or individual panel microinverters), or replace our "old" array with modern equipment. Spouse favors the pergola for décor reasons and I think it's the cheaper approach.

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HECO $16/month: Is it the same as the connection charge whether you have net metering or not?
Yes. Oh, no, that would be way too simple and too many customers would understand what they're actually paying. On the rare months when we generate more than we use, our bill will say "Mimimum charge $16". That's all. Of course now that our kid is in college, those months may become more frequent.

During a typical month we'll consume a net of 30-50 KWHrs. For example, last month we generated 277 KWHrs and bought another 42 KWHrs from HECO. Of course the reality is that we were generating way more than we used during most days and then sucking it back from HECO overnight or on rainy days. That's the beauty of net metering-- using HECO as your storage battery.

For that month we were charged the following:
$8.00 CUSTOMER CHARGE
$3.49 NON-FUEL ENERGY
$3.73 BASE FUEL ENERGY
$1.07 INTERIM INCREASE 2009
$1.08 INTERIM INCREASE 2007
$0.20 PBF SURCHARGE
$2.12 ENERGY COST ADJUSTMENT
$0.01 IRP COST RECOVERY
$19.70

Reading the fine print on HECO's website, using 42 of their KWHrs means we paid a "base fuel energy", a "PBF surcharge", and an "energy cost adjustment". If we had used zero of their KWHrs then taking those off the bill works out to a net charge of $13.65.

That's lower than the $16 minimum, so HECO must have had a good month for maintenance/repairs/excess demand. Other monthly bills had higher non-fuel energy charges and IRP cost recovery charges to add up to more than $16. It'd be interesting to see if we had used zero KWHrs on that month whether they would have charged us $13.65 or $16... probably the $16. Still a bargain.

Despite all this modern hifalutin' net-energy metering and our digital meter (which can communicate with a utility over its power lines), we still have a human meter reader walking the streets. HECO's 20-year-old billing computers still don't do net-metering so they print a separate net-metering spreadsheet in our snail-mail paper bill to track the 12-month excess power generation. No complaints, though; I've heard that California's PG&E net-metering statement is almost as bad as a cell-phone bill.

Thanks for asking these questions-- they sparked a thought. Our current system uses a big-box net-metering inverter that has to sense HECO's grid voltage before it'll turn itself on and convert photons to electricity. If a hurricane or an earthquake take down HECO then our inverter won't turn on and we're out of the solar business. But writing this post makes me realize that the new microinverters may not necessarily need to sense HECO's bus voltage before they do their power conversion. If that's the case then we'd definitely want to add them to our EV-charging PV array just for the ability to generate some electricity after a hurricane. I'll have to check into their specs next time I'm talking to a solar company.
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Old 11-06-2010, 01:49 AM   #105
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As to the price, my EV averages 4 miles/Kwh (over 4500 miles so far).
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Sample: If gasoline is $2.80/gal and electricity is $0.10 per KWH:
Gasoline motive energy unit per dollar= 114000/2.8 x .2 = 8142
Electricty motive energy units per dollar = 3412/0.10 x .64 =21,836
8142/21836 = 0.37 (37%).

Good but still higher than I expected. Using Zathras' above mileage and the real world fuel economy of a new Corolla, 30mpg. Electricity @ $0.10/kwh and gasoline @ $2.60/gal, both are current in Houston.

Electricity: 10/4 = 2.5 cents/mile
Gasoline: 260/30 = 8.7 cents/mile
So the fuel cost for EV is only 29% of the gasoline Corolla.

But the same Corolla can also be driven conservatively resulting in 35mpg. So fuel cost is only 7.4 cents/mile. 34% in this case and is closer to your number.
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Old 11-06-2010, 02:19 AM   #106
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For that month we were charged the following:
$8.00 CUSTOMER CHARGE
$3.49 NON-FUEL ENERGY
$3.73 BASE FUEL ENERGY
$1.07 INTERIM INCREASE 2009
$1.08 INTERIM INCREASE 2007
$0.20 PBF SURCHARGE
$2.12 ENERGY COST ADJUSTMENT
$0.01 IRP COST RECOVERY
$19.70
I've got to stop complaining about the complexity of my electric bill. Here's the itemized bill for last month (one of the two months in Houston when neither the A/C nor the heater is running). Total usage is 388 kwh.

ELECTRIC CHARGE 30.81
FUEL CHARGE 17.84
FUEL REFUND 388 KWH @ $0.0188800- 7.33CR
TOTAL MONTHLY CHARGES 41.32

BTW, that's 10.65cents/kwh which is higher than the average 10.00cents/kwh for the past 12 months.
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Old 11-06-2010, 02:26 AM   #107
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Our current system uses a big-box net-metering inverter that has to sense HECO's grid voltage before it'll turn itself on and convert photons to electricity. If a hurricane or an earthquake take down HECO then our inverter won't turn on and we're out of the solar business. But writing this post makes me realize that the new microinverters may not necessarily need to sense HECO's bus voltage before they do their power conversion. If that's the case then we'd definitely want to add them to our EV-charging PV array just for the ability to generate some electricity after a hurricane. I'll have to check into their specs next time I'm talking to a solar company.
Sorry about that Sounds like you're looking for excuses to do more tinkering.
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Old 11-06-2010, 05:00 AM   #108
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I spent about an hour browsing the internet for an unbiased and complete life-cycle cost analysis for two alternatives: cost of driving a EV vs cost of driving a gasoline powered vehicle. (ie, green power vs brown power).

There were certainly a lot of biased economic comparisons, tilted toward the side of using an EV, but not one analysis which gave a head-to-head comparison. Makes me think of Jack Nicolas' famous statement, "You can't handle the truth".

Just to be clear, I am talking about an ordinary homeowner who must pay the true out-of-pocket expenses for everything. No subsidies, no government rebates, no special deals on electrical company "net metering", etc.

If you are going to use solar panels, then your house must be 100% energy independent from the power company. A life-cycle cost analysis must include depreciation and maintenance costs, for a solar system. Otherwise, you just pay full energy cost for buying electricity from the power companies.

Let us not forget, a power company buys electricity from consumers in the day time when the sun shines because government regulations say they must. In reality, buying power at retail prices during the day is a bad deal for power companies because that is a time of low energy use.

I want to compare apples to apples and oranges to oranges on a head-to-head basis, on a level playing field to use as many metaphors as possible.

Then, what kind of car would the average American choose to buy and drive? Battery powered or gasoline powered? I'll guess it is the gasoline car.
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Old 11-06-2010, 07:43 AM   #109
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Then, what kind of car would the average American choose to buy and drive? Battery powered or gasoline powered? I'll guess it is the gasoline car.
My guess is the same as yours. If you make all the assumptions you've made (no govt subsidies, etc), then the gasoline powered car is almost surely a lower cost and more practical alternative for the vast majority of Americans. If not, the market would already be brimming with plug-in cars. But:
1) That's not to say that they won't make economic sense for some people. Just as a Chevy Suburban or a moped make sense for some people. The plug-in EV is right for some "missions", and wrong for others. At the present state of technology and price, they're likely the wrong economic choice for most users. Just like a moped or a Suburban.
2) Total cost per mile or per month isn't the only marketplace criteria. If it were, no one would buy an Infinity, Lexus, or Lincoln. Folks want to make an eco-statement, so they should be able to. Heck, if the electricity they are using to fuel the thing is really "green", then they are doing something for the planet--let them revel in it and leave more hydrocarbons for me to burn.

I just don't want to subsidize this behavior with taxes.
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Old 11-06-2010, 08:25 AM   #110
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Interesting reading, good to see all the activity on this subject - I've been busy and have wanted to respond, but there are just too many points to address for the time I have right now! I'll try to pick a few later.

But I'll repeat a statement I've made before, along the lines of what samclem just posted: If EVs were even close to being ready for the US market, we'd be seeing them all over the place in Europe, where they have high petrol costs, shorter average commutes and smaller cars on average, and a lot of wind generated electricity (and France has ~ 80% nuke). That is where the first inroads would be made.

But we don't see that, so it's really just silly to think there is any significant market here in the US at this time. And yes, if anyone wants 'green' bragging rights, then they can pay for them themselves.

-ERD50.
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Old 11-06-2010, 09:09 AM   #111
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Interesting reading, good to see all the activity on this subject - I've been busy and have wanted to respond, but there are just too many points to address for the time I have right now! I'll try to pick a few later.

But I'll repeat a statement I've made before, along the lines of what samclem just posted: If EVs were even close to being ready for the US market, we'd be seeing them all over the place in Europe, where they have high petrol costs, shorter average commutes and smaller cars on average, and a lot of wind generated electricity (and France has ~ 80% nuke). That is where the first inroads would be made.

But we don't see that, so it's really just silly to think there is any significant market here in the US at this time. And yes, if anyone wants 'green' bragging rights, then they can pay for them themselves.

And to take this thinking one step farther, suppose the government were to get rid of all these subsidies, net metering buy-back, and other half-hidden costs that give the edge to the hybrid, half-gas, half batteries car. And suppose instead they were to place a tariff or consumption tax on petroleum product consumption - like they do with the "sin tax" on cigarettes and alcohol. After all, that is our real goal - isn't it? Reduce our dependence on petroleum?

This would encourage the development of REAL alternative energy cars, giving the market and private enterprise a little bonus to think a harder about finding a practical and economic alternative to petroleum based cars. Then we would be moving in the right direction. With luck, we might even find something that could replace the battery. I have this haunting feeling we are going to dread the day when we have millions of old car batteries on our hands that are a real bitch to dispose of.
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Old 11-06-2010, 09:37 AM   #112
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May have to admit, EV is in my and DW's future.

EVgrampsGranny.gif



Shamelessly stolen from JagLovers website.
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Old 11-06-2010, 10:14 AM   #113
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And to take this thinking one step farther, suppose the government were to get rid of all these subsidies, net metering buy-back, and other half-hidden costs that give the edge to the hybrid, half-gas, half batteries car. And suppose instead they were to place a tariff or consumption tax on petroleum product consumption - like they do with the "sin tax" on cigarettes and alcohol. After all, that is our real goal - isn't it? Reduce our dependence on petroleum?

This would encourage the development of REAL alternative energy cars, giving the market and private enterprise a little bonus to think a harder about finding a practical and economic alternative to petroleum based cars. Then we would be moving in the right direction. With luck, we might even find something that could replace the battery. I have this haunting feeling we are going to dread the day when we have millions of old car batteries on our hands that are a real bitch to dispose of.
I agree completely. Loose the subsidies, for solar, batteries, oil, trucking, etc.
Adding a tax to carbon/energy is the best solution. However, I have yet to see any politician willing to do this unless they are not planning to run for re-election.
So without that solution, adding subsidies seems to be the next best option.
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Old 11-06-2010, 10:25 AM   #114
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May have to admit, EV is in my and DW's future.

Attachment 10377



Shamelessly stolen from JagLovers website.
Jags are too sluggish
I prefer something like this:

http://www.teslamotors.com/roadster/gallery/view/5135
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Old 11-06-2010, 10:32 AM   #115
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Adding a tax to carbon/energy is the best solution. However, I have yet to see any politician willing to do this unless they are not planning to run for re-election.
I think because this only makes sense once we look at the costs (they will be very high) and agree that the benefit we are buying is worth it. The benefit is very unclear to the voting public, and the costs are very clear.
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So without that solution, adding subsidies seems to be the next best option.
If the most efficient solution isn't acceptable, surely an even more suboptimal solution makes even less sense. But, maybe it's more palatable because the costs are less direct. "Someone else" pays, and at a later time, and we can kid ourselves about "doing something." That's a bad path.
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Old 11-06-2010, 10:36 AM   #116
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In reality, buying power at retail prices during the day is a bad deal for power companies because that is a time of low energy use.
You lost me right here...

By far the biggest electricity hog in this part of the world is a/c on a long, hot summer day.
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Old 11-06-2010, 11:50 AM   #117
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Jags are too sluggish
I prefer something like this:

Roadster Image Gallery | Photo Details | Tesla Motors
Looks great, do you own one?

I am a jag fan, have two, looking for a third. A convert from Benz.
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Old 11-06-2010, 12:46 PM   #118
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Looks great, do you own one?

I am a jag fan, have two, looking for a third. A convert from Benz.
Thanks!
Yes, although blue, not red.
I am actually not a sports car enthusiast, however it is the only highway capable EV that fits my driving profile.
Eventually we plan on owning one Tesla model S sedan and one Rav4 EV.
Hopefully by 2013.
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Old 11-06-2010, 05:29 PM   #119
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Thanks!
Yes, although blue, not red.
Wow, very cool.

Race ya'! Chicago to Minneapolis, heh, heh , heh (Google Maps says 377 miles). I might need to stop for gas in my Volvo S40, probably not with highway mpg though.

Sorry, couldn't resist (yes, a part of me is jealous). Must be fun to punch it, with all that low end torque.

-ERD50
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