Monthly Charging Cost - anyone projected or tracked it?

I don't have a Kill-a-Watt hooked to my charger, but I can do some pretty easy estimates for my usage at home:

$0.26 average cost for a KWh (according to latest PG&E bill)
3 hours every night
5 nights a week (not home on the weekends, not using the car then)
4.5 weeks a month

Comes out to .26 * 3 * 5 * 4.5 = $17.55 in electricity. Considering that gas costs around $4.40 a gallon here, that's about 4 gallons worth of gas. If we assume that I actually can get 11.3 miles of EV per charge, that same $17.55 propels me 254 miles. Or the equivalent of about 63mpg. Or 7 cents a mile.

No matter how I look at it, I am saving money with the car. If I can charge at work for free (which I do), I save even more money.

 

can you really use the average cost? i think you have to look at it as "no prius" vs. "prius". for me since i'm always in the top tier without my leaf and prius, the actual cost to charge the cars is 35c/kwh (or whatever the top E-1 rate is right now, it changes depending on the time of year and how many time PG&E has been to the PUC this year )

 

34 cents is the top rate. We're always in the top tier as well, so I feel your pain. Last month's bill (March) was 791KWh which came out to about 26 cents a KWh. The previous month (Feb) was 1049KWh which came out to about 27 cents a KWh. What's funny is that I got the PiP in March, so I would have expected the usage to go up in March. The worst month I had last year was 1188 KWh at an average cost of 30 cents a KWh. Our usage pattern is a bit difficult to predict...

 

right before i got the leaf i replaced most of the halogen floodlights in my house with CFL floods. this saved me about 100KWh per month, and the leaf is consuming about 150KWh per month, so in terms of pre-electric car vs. post, we're doing pretty good.

of course, the PIP is going to make it worse.

but i guess what i was trying to say is that, is it "fair" to your computers and lights to charge them more per kwh as their cost of operation when it's the PIP that's increasing the average cost of power? in the end, the extra amount you paid because of the PIP is 0.34c/kwh* kwh consumed by the PIP...

 

Only 150KWh for the Leaf? That seems rather low usage. I would expect you to be pulling at least 250 to 300 KWh per month. Or this the net effect of replacing the light bulbs and then getting the Leaf?

Well, based on my usage pattern so far, it's only about 60 to 70 KWh per month. But that's charging once per day at home during the week and nothing on the weekend.

If my usage pattern was consistent over the year, then your way of accounting for the power consumed would be perfectly fine. Looking at my bills for the last year, I had a high of 1068 KWh and a low of 791 KWh. March of last year was 1047 and this year it was 791. January of last year was 1035 and this year was 1018. Totally unpredictable. Thus I'm kind of forced to look at the overall cost rather than an incremental cost to run the PiP.

I'm hoping that the combination of going to E6-TOU and putting solar on the roof will drop me out of the top tier and maybe even down further. According to PG&E, just by going to E6 will lower my yearly cost by $90 to $180. Adding in solar should drop it another $600 or so yearly.

 

Yes, I am.

Everyday to document the PIP I take photos of the Kill A Watt and the PIP displays before going to work, then I take photos again before lunch, after lunch, before going home with photo of the work Kill A Watt, then display photos when I get home.

I add the info to Excel that I've posted here.

I got my PIP March 14, now with 648 miles, EV Display shows 96 kWh and 5 gallons, EV%= 58 and HV%=42. Adding the home & Work Kill A Watt units, I get 113 kWh.

 

well, we're driving ~500 miles per month in the leaf. 150 at the wall is 3.33mi/kwh (assuming charger efficiency of 85%) which is just about right for the leaf. the car thinks its getting 3.9mi/kwh but all evidence is that it's too optimistic in it's calculation.

but as long as you are always in the highest tier before adding the PIP, then the incremental cost of the PIP is all in the highest tier. 791KWh should definitely be in the highest tier, at least according to my bill.

yeah, this is the way to go. i ended up not doing it because my roof is kind of complex and every roofer i talked to gave me a different story about how hard it would be to put the comp roof on that the solar guys wanted. the fact that they all said something different definitely worried me.

anyway, to the topic of this thread: i've had the car for 11 days and according to the car i've done 124 EV miles using 34KWh and 167 gasoline miles (3 gallons). however, i've driven the car a lot more than we normally would drive. anyhow assuming a charge efficiency of 85% that's 40KWh at the wall. that would imply 120KWh per month, but again i think this first week is a bit on the heavy side.