LEAF Charging Costs

[DaveEV]

... if you use A/C in afternoon on hottest months, like I do, I fall into tier 3 for several months per year, which is about 24 cents/kwh.

A/C in the afternoon would be the ideal load for a PV. The generation & load would be well matched.

It's not quite perfect - PV power starts falling off mid afternoon and typically it's hottest mid afternoon.

You'd need to have west facing panels to generate more power in the afternoon, but then you'd be giving up some on total power production.

Peak rates generally don't start until 12pm or so and extend until 6pm or so - from 4-6pm PV systems only be generating a fraction of their peak output.

Here's my system's typical output from noon to 6pm:

12: 2.6 kW
13: 2.7 kW
14: 2.6 KW
15: 2.4 kW
16: 2.0 kW
17: 1.5 kW
18: 0.8 kW

Solar noon is just before 1pm - my panels are mounted nearly flat (just slightly to the west). You can see how fast power drops once you get farther than 2 hours from solar noon.

You have to be very careful going on a TOU system if you are planning on using AC during peak times - I would recommend sticking on a standard domestic rate plan for a year with hourly monitoring of net generation/usage for a full year (or at least monitoring of the meter at each TOU period transition) to see if it would help or hurt your bill. Most utilities make you stick on a billing plan for a full year once you change...

 

[LEAFfan]

You'd need to contact your local utility, their clean-air helpline if they have one. My utility wants me to pay for the second meter, which is too expensive to be practical in my situation, but it sounds like at least one other's utility will do the work for free.

SCE (Southern California Edison) has a program for second meter dedicated to car charging port. This is one advantage of having a special charging port - the utility can give you a special rate for the car alone. You can keep your house on your regular rate tariff. The second meter has a TOU (Time-of-Use) tariff. Off-peak is Midnight to 6 AM. Off-peak price was 8 cents/kwh, but they just raised it to 6 cents/kwh distribution + generation (4-6 cents/kwh), total up to 12 cents/kwh. For folks in other areas, this probably sounds high, but SCE normal rate is tiered, and if you use A/C in afternoon on hottest months, like I do, I fall into tier 3 for several months per year, which is about 24 cents/kwh. There appears to be no charge (except installation) for the second meter, and there is a 50% tax credit for the installation. I have had the Edison Service Planner at my house, but he told me the second-meter option was a different department.

Has anyone else contracted to install the second meter ?

I'm in Arizona with SRP. I don't think I'm going to need a second meter or even if that is an option...I'll have to check. Right now, I'm on the EZ-3 TOU plan...3-6 PM is on-peak and all the rest are off-peak @ .08/kwh including weekends and holidays.

 

[tbleakne]

... if you use A/C in afternoon on hottest months, like I do, I fall into tier 3 for several months per year, which is about 24 cents/kwh.

A/C in the afternoon would be the ideal load for a PV. The generation & load would be well matched.

I agree. The 24 KWh battery would also provide a very substantial backup for a blackout. The lack of provision for this (sending power back from the car to the house) is a definite disappointment. However, it is possible draining the battery every Summer afternoon would shorten its life. Better to use solar to mitigate A/C drain. In my case, my roof has shade issues.

 

[redLEAF]

I (honestly) went through the most recent threads and didn't see this article, all I can say is that even though HI is a great place to live (I had a sister who lived out there a few years back) I wouldn't want to pay these charging rates; here in IL we're close to the average but as this article states I'm planning to contact ComEd to see what impact adding an EV would do -- BTW great discussion on this topic --

http://www.edmunds.com/fuel-economy/the-true-cost-of-powering-an-electric-car.html

 

[JasonT]

I (honestly) went through the most recent threads and didn't see this article, all I can say is that even though HI is a great place to live (I had a sister who lived out there a few years back) I wouldn't want to pay these charging rates

Me neither, but I wouldn't want to pay their gas rates either. Poking around the web, got one estimate that the average right now is $3.65-$3.75/gallon (depending on source).

 

[DaveinOlyWA]

my electric bill. it wont take you long to see why i just charge a straight 10.3 cents /kwh. as you can see, it would take an accountant and mathematician to sort this out.

but basically used 850 kwh so if divided by total bill it works out to 10.268 cents /kwh. now if i just took the 2nd tier rate minus the discounts and estimated taxes, it figures to just over 10.2, so i took the higher

 

[Anonymous]

I do similar to Dave with my bill (which looks almost identical to his, since we're both obviously on PSE).

My latest bill had a total charge of $96.22 (for the electric portion) and that was a total of 988 kWh. I actually subtract out the "basic charge" elements, since that charge is a flat rate per meter. That works out to $0.0901/kWh.

 

[IBELEAF]

my electric bill. it wont take you long to see why i just charge a straight 10.3 cents /kwh. as you can see, it would take an accountant and mathematician to sort this out.

but basically used 850 kwh so if divided by total bill it works out to 10.268 cents /kwh. now if i just took the 2nd tier rate minus the discounts and estimated taxes, it figures to just over 10.2, so i took the higher

Aren't you getting 0.085578 in the first 600 kWh and 250 kWh at 0.010268... So you are including other charges as well, but basically your average should be 0.0908

 

[DaveinOlyWA]

well, i "could" figure it that way since i would have some of the charge on the lower tier, but i choose to figure it based on my maximum cost.

if i did it based on just what the KWH cost me in real figures with taxes, etc, its just at 10 cents so not a lot of difference either way and the connect charge would apply with or without the car plugged in.

besides... i already have caused bad blood in the break room at work when people were complaining about the price of gas and i mentioned it cost me 54 cents to commute.

one asked "is that one way?"

i said "oh no!! its not THAT much. that is my round trip cost"

 

[garygid]

Easy to read and understand compared to my SDG&E Net-metering statement (with Solar PV over-generation).