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Discussion Starter #1 (Edited)
I’ve been lurking around for a few weeks learning as much as I can about the Volt. It was really bothering me not knowing whether or not the high price of the Volt made it obsolete. My summer class load is exceptionally boring so I’ve spent my “free time” in class building a pretty extensive cost analysis excel “program” if you will. The program is very simple and helpful, it requires you to input the following:

1) The price you are willing to pay for a regular car in 2010
2) Regular car average fuel efficiency (MPG)
3) Estimated regular car maintenance cost per year
4) Number of miles you drive on an average weekday
5) Number of miles you drive on an average weekend day
6) Number of long driving trips you take per year
7) The average total distance of one long driving trip (miles)
8) Amount of down payment on vehicle you can afford
9) Interest rate you would expect on a car loan given your credit score
10) Number of years you want it to take to pay off the vehicle
11) Trade in value of your current car (in two years)
12) Sales tax of your state
13) monthly car insurance payment

Then it takes the known facts about the Volt (which can all be changed to see effects) and gives a detailed breakdown of a ton of different things. The breakdown takes into account three different cases for gas and electricity prices (worst case/exponential growth, optimistic linear growth, and a case for values of gas and electric prices which you fill out). In the end you can see exactly how much you will be paying each year for both the Volt and a regular car, (interest, gas price and all). When you account for growth in gas prices it is pretty surprising to see the results. It will make a lot more sense once you see it. It really helped me understand all the cost involved and how it’s going to play out. I figured you guys would like to see it too (since half the post here seem to be about cost speculation).

I spent a lot of time making sure this thing would be robust to any numbers, it has a bunch of IF statements so you can play around with driving ranges below and above the 40 mile range as well as change the all electric range and it will all still work.

If there are any mistakes, things I missed or bugs please contact me (gtg334q at mail.GAtech.edu) and let me know, so I can edit it, it might be a little hard for someone to figure out…

I’ve also attached an example of how to fill out the sheet if it is confusing. It might be easier to understand if you look at the example first and then start with your own.

Hope this helps finally answer the question about price of the Volt!
 

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Very good. One little modifier though may be the expected length of ownership. You'll save on fuel but the savings will be amortized over the life of the vehicle.

Edit: along with expected cost of gas (average) during life of vehicle.

that way we can see if eventually it'll be a zero sum game, a bust, or a boon without the mental math
 

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Discussion Starter #3
I'm not exactly sure what you mean. That should be covered in the "Cost analysis tab" thats what the whole red and green business is. where are you doing mental math?
 

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Very good. One little modifier though may be the expected length of ownership. You'll save on fuel but the savings will be amortized over the life of the vehicle.

Edit: along with expected cost of gas (average) during life of vehicle.

that way we can see if eventually it'll be a zero sum game, a bust, or a boon without the mental math

Good point on this. I used to own a Hyundai Excel and have deducted from my taxable income 5 times its purchased value when I held on to it for 10 years. I gave it away to a Pastor even though it still runs good and passes smog test.

So how long you want to hold on, and assuming that your repairs would become more frequent after the first 5 years of amortization, :D

Electric cars are projected to last longer with fewer maintenance. And also bear in mind that significant number of us would like to hold on to our purchased cars much longer than the amortized payments, so we should run the analysis and comparison past the payment period.

And if you want, here is a reference to the actual retail data of electricity prices of each of the different states of the USA that you can include in your analysis:

http://www.eia.doe.gov/cneaf/electricity/page/sales_revenue.xls

In the case of California, using simple averages, our electricity rates increased by 2.35%/year, but if we used the non-linear compounding method of growth rate, the trend shows a 2.19% compounded rate of increase. The linear vs non-linear trends are not significantly different than each other because of year to year variability that in some years we did have some declining rates due to the refund from the Enron snafu. So I just used the higher value for conservative analysis.
 

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I'm not exactly sure what you mean. That should be covered in the "Cost analysis tab" thats what the whole red and green business is. where are you doing mental math?
I mean, it'll calculate gallons of fuel used over the payment period. If it could calculate it out past the payment period and over the life of the car as well as calculating average cost saved on fuel vs electricity.

You'd have to enter a few field. One for expected lifespan. A second for expected cost of fuel per gallon. And a third for basic electricity rates.
 

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Discussion Starter #6
I mean, it'll calculate gallons of fuel used over the payment period. If it could calculate it out past the payment period and over the life of the car as well as calculating average cost saved on fuel vs electricity.

You'd have to enter a few field. One for expected lifespan. A second for expected cost of fuel per gallon. And a third for basic electricity rates.
I'm pretty sure all of that stuff is in there in the third tab labeled "Cost Analysis" see: "Regular car gas cost per year, Volt gas cost per year, etc" the final column gives you the cost savings by year and the break even point.

Also, I’m curious has this helped anyone? What did the results show for your case? Any other suggestions for improvement?
 

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Sometimes I can have a hard time reading new graphs but I don't see where fuel costs are explored. I only see fuel and electricity consumption but not actually the cost. That's why I threw it in in my example because ultimately the cost of the fuel will be the tipping point for most people.

It's still a great spreadsheet.
 

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Discussion Starter #8
Yeah it’s hard to explain just because I made it so it all makes since to me ya know….

So if you want to explore how cost effect if the Volt is worth it you need to go to the tab labeled “Your Projection of Gas Prices” - once you click this tab you can fill out whatever you think the prices of gas and electricity will be in the future (research your area). Once the data is filled in you can go back to the “cost analysis” tab and the last/third group of data labeled “cost analysis of what you think gas and electric prices will be” will show all the numbers you are looking for by year. The programs pretty powerful once you get it, you can change any number of variables to see the effects. Let me know if I’m not getting what you’re looking for and I’ll make sure I add it.

Also the prices for the other two cost analysis are found in the tabs labeled “exponential projection” and “linear projection” if you want to see what values I used for each year
 

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Ah...ok...I see what happened. I'm using a version of Open Office that I'm not familiar with and I didn't see any tabs. I see them now.

Ah..now I feel like a dummy not having seen them.

Edit: Really really feel like an idiot. Normally I catch small things like that but since I only downloaded the example I saw only the main variable page. This really really is an excellent work you've done.

Edit2: I really will pass this along. Did you tag it for credit? If not I'll do so for you when I pass it along.
 

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So far so good. On the projected costs, right now nationwide everyone pays different rates for fuel and electricity.

Would it be possible to append it so people can place their current prices and an algorithm projects expected costs? I imagine that the price growth curve would be the same across America (ie. Los Angeles pays 30-50 cents more per gallon of gas than New Orleans, La). Same with electricity. I pay just over 7 cents a kWh right now so the expected price is already off for me right now.
 

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Discussion Starter #12
That involves too much variability then I know how to capture. That’s the reason I included the “what do you think” part. Everyone’s going to be different and can fill that part out if they really want to get into detail about their specific needs. Otherwise the linear projection should give them a good aproximation.
 

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GAtechVOLT,

Very slick! However, I think I found a bug.

It looks like in the "Your Projection" section of "Cost Analysis" that Volt fuel consumption on long trips isn't being picked up. That's cells F35 to F45. I replaced:

=(Variables!$B$29/Variables!$B$23)*'Your Projection of Gas Prices'!B11
=(Variables!$B$29/Variables!$B$23)*'Your Projection of Gas Prices'!B12
...

with:

=Variables!$B$44*'Your Projection of Gas Prices'!B11
=Variables!$B$44*'Your Projection of Gas Prices'!B12
...

and I think that's correct. I could be wrong.
 

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Modifications to compare with HEV and incorporating battery cost

Thanks very much for this well-done model.

I modified the model slightly to make a couple of things easier for me to do (modifications included in the mod.zip file in this post). First, I like to make comparisons to the equivalent HEV vehicle (e.g. the Prius), so I modified the price information to add the battery cost to the HEV price and to assume the same MPG as the equivalent HEV. Second, I changed things slightly to allow for changes to the battery capacity (and thus all-electric range and price). Third, I made the rebate scale with the all-electric range.

Also, I changed the baseline commute miles information to be consistent with the numbers I've found for the average in the U.S. (23 miles) and I changed the numbers in the "your projections" tab to be my projections.

For me this reinforces a few things. First, the battery costs need to get down to $400/kWh for the average commuter to make the Volt close to economically viable without rebates (using my fuel and electricity cost projections). Second, the Volt would be economically viable (without rebates) for the average U.S. commuter (23 commute miles) with $700/kWh batteries if the all-electric range was reduced to 20 miles--choices in battery capacity would make the Volt viable for more buyers. Third, a $125/mile-AER rebate would probably make the Volt (with 40-mile AER and $700/kWh batteries) close to viable for the average commuter--the government pays for excess battery capacity. Finally, if battery costs get down to $350/kWh, gas prices stay high, and cars are offered with a range of battery capacity, many PHEV's will be sold.

Bottom line: The batteries are expensive and you don't want more battery capacity than you need for your daily commute--it doesn't make economic sense.
 

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Discussion Starter #16
I was notified of another error. The sales tax you will pay for the Volt will be on the full price (I had it after the rebate was taken out). Also, I had the sales tax computed using the loan interest parentage instead of the sales tax percentage…whups. I added a version counter to the file name. Currently we are on V1.1 if the number changes you know I made a change.

Pdt - I tried to cover the changes in battery capacity by allowing the “amount of kwh to charge” cell to be changed, I didn’t know the price per kwh. Interesting modifications. How come you assumed the HEV and the Volt would have the same mpg?
 

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I was notified of another error. The sales tax you will pay for the Volt will be on the full price (I had it after the rebate was taken out). Also, I had the sales tax computed using the loan interest parentage instead of the sales tax percentage…whups. I added a version counter to the file name. Currently we are on V1.1 if the number changes you know I made a change.

Pdt - I tried to cover the changes in battery capacity by allowing the “amount of kwh to charge” cell to be changed, I didn’t know the price per kwh. Interesting modifications. How come you assumed the HEV and the Volt would have the same mpg?
In charge-sustaining mode the Volt will operate essentially the same as an HEV. I don't see much of an advantage to the Volt architecture in charge-sustaining mode and it will have more dead battery weight to drag around. Thanks again for the model. I found it very well-constructed and useful.
 

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I was notified of another error. The sales tax you will pay for the Volt will be on the full price (I had it after the rebate was taken out). Also, I had the sales tax computed using the loan interest parentage instead of the sales tax percentage…whups. I added a version counter to the file name. Currently we are on V1.1 if the number changes you know I made a change.

Pdt - I tried to cover the changes in battery capacity by allowing the “amount of kwh to charge” cell to be changed, I didn’t know the price per kwh. Interesting modifications. How come you assumed the HEV and the Volt would have the same mpg?
Sorry, I realized that I may have misunderstood the question. I was just converting your model to be a comparison of HEV vs PHEV to better understand when the PHEV will start to be more economical over HEV.
 

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Bump. Not sure how I ran across this but I was not around here when it came out. Even the the 1st Gen Volt is probably not being purchased for cost savings some may like this spreadsheet that folks complimented. See first post.
 
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