For some reason our county insists on running electricity lines through the air, and we also have heavy windstorms. Put the 2 together and we get power outages every year. In 2006 I actually had a power outage for 10 straight days (in the middle of a city 
). I lived in Africa for 25 years, and I've never seen anything like that. Anyway, getting off topic...
If something like that happens again it can leave me quite stranded in the Model S. So I'm considering getting a natural gas backup generator, and wanted to run the numbers to see how much it would be to charge a Model S.
Turns out to be very interesting:
Costco has a cheap Honeywell (Model 006032-0) for $2700. Gives about 40 Amps continuous @ 240V. Familiar numbers to all of us :smile:.
That should give you a nice 240 mile standard charge in about 8 hours. Ok, so how much would it cost to charge a Model S using that?
Spec for the Honeywell says 156 cu.ft/gas per hour at full load (i.e. 40 AMP)
156 cu.ft/hour x 8 hours totals = 1248 cu.ft. of natural gas for a standard charge.
1248 cu.ft of natural gas = 1.317 MMBTUs. (x 1.056 for relative heat content and / 1000. Why they sell it like this is beyond me.)
Now here comes the fun part:
2012 national average for natural gas is $10.98 per MMBTU.
1.317 MMBTUs @ $10.98 each = $14.47 to standard charge a 85kWh.
To put that in perspective, at a gas price of $3.62 per gallon, $14.47 buys about 4 gallons of gas. To travel 240 miles on 4 gallons, gives you 60 mpg. Heck, using Chad's worst case 2/3 planning equation, you'd still be getting close to 40 mpg.
There are obviously other cars that get 40, and even a few that break 50. But then you're not talking about something the size & performance of a Model S.
And all this from a rinky dink home generator.
These cars are crazy efficient.:love:
PS: Of course this is just for an emergency backup, I realize that natural gas used this way would still release a lot of CO2. Usually I'm either 100% on hydro or baseline.
). I lived in Africa for 25 years, and I've never seen anything like that. Anyway, getting off topic...If something like that happens again it can leave me quite stranded in the Model S. So I'm considering getting a natural gas backup generator, and wanted to run the numbers to see how much it would be to charge a Model S.
Turns out to be very interesting:
Costco has a cheap Honeywell (Model 006032-0) for $2700. Gives about 40 Amps continuous @ 240V. Familiar numbers to all of us :smile:.
That should give you a nice 240 mile standard charge in about 8 hours. Ok, so how much would it cost to charge a Model S using that?
Spec for the Honeywell says 156 cu.ft/gas per hour at full load (i.e. 40 AMP)
156 cu.ft/hour x 8 hours totals = 1248 cu.ft. of natural gas for a standard charge.
1248 cu.ft of natural gas = 1.317 MMBTUs. (x 1.056 for relative heat content and / 1000. Why they sell it like this is beyond me.)
Now here comes the fun part:
2012 national average for natural gas is $10.98 per MMBTU.
1.317 MMBTUs @ $10.98 each = $14.47 to standard charge a 85kWh.
To put that in perspective, at a gas price of $3.62 per gallon, $14.47 buys about 4 gallons of gas. To travel 240 miles on 4 gallons, gives you 60 mpg. Heck, using Chad's worst case 2/3 planning equation, you'd still be getting close to 40 mpg.
There are obviously other cars that get 40, and even a few that break 50. But then you're not talking about something the size & performance of a Model S.
And all this from a rinky dink home generator.
These cars are crazy efficient.:love:
PS: Of course this is just for an emergency backup, I realize that natural gas used this way would still release a lot of CO2. Usually I'm either 100% on hydro or baseline.
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