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Discussion Starter #1
Could use some input/advice regarding my electric company's EV rate and associated calculation.
I don't have to go on the EV rate. The whole house at would be at this rate (no separate meter for the EV circuit).
The figures below are for the energy & distribution charges combined.

Vehicle is 2015 Volt. 28 mile RT commute 7 of 14 days (12 hour shifts, 9a-9p). I probably do as much running errands, etc. on days off. I'm in Michigan. Also, wife is a teacher (summers off and home w/ kids during the day re: A/C usage). I can charge at Level 2 starting at after 11pm with no issues to use the cheapest 9 cent kWH rate.

Both rates are for the whole house.
Current Rates: no time of day metering
October – May = 13 cents per kWH all day, every day
June -September = 13 cents for the first 600 kWH. 601 kWH and up = 16 cents.

For reference, my past 2 years (note: PRE-EV ownership) kWH usage was 13,952. Average monthly kHw is 581.33 a month. A total of 821 kWH were over the 600 during the "summer" rate at 3 cents more. However, in 3 of the 8 "summer" months, we didn't go over the 600. I calculate an average of 13.17 cents/kWH.

EV Rate
All Year: Weekends, Holidays, and every day from 11pm-7am are off peak 9 cents per kWH. I'd save 4 cents kWH during charging overnight.
October-May
Monday-Friday 7am-11pm = 13 cents

June-September
Monday-Friday 7am-2pm and 6pm-11pm 15 cents
Monday –Friday 2pm-6pm 22 cents ouch

There's a 4 cent incentive to charge at night. There's also a 6 to 9 cent premium during 20 peak hours a week during the 4 hot months.
I assume i'll use 10-12 kWH to charge from 0-10 miles left (please correct me if i'm wrong). I assume that my monthly usage will go up by 335 kWH a month. This will undoubtedly push me over 600 kWH during the summer.

My expected monthly average will rise to 916 kWH. At the current rate, i'd be going up $42.90 for 8 months and $52.8 for the summer. If i go to the EV rate, this increase is only $29.70.
The 8 months are a no brainer in favor of the EV rate. I don't think i can flip-flop seasonally as they install a new meter for the EV rate.
What do you think about the summer eating away at that? I'm thinking (since the whole house is cheap at night) I can set the dishwasher on delay and maybe the washer, too.

Thanks in advance for any input. It's been a great 1st week with the Volt.
 

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Congrats on the Volt!

I'm interested to see what some MI people say about this. I know that in Southern California, our SoCal Edison utilities company offers an EV plan, but a quick review showed that it is actually not in most people's best interest to switch. You would need to be a corner case for the plan to actually benefit you.

This MI plan might be the same way. It sounds like you've already run the numbers, and if it doesn't appear to make sense to you, then I would say don't make the switch. I guess what I'm saying is, just because something is marketed for you doesn't mean it's your best option.
 

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Here in southern Illinois we only have a FLAT rate 24/7 but it's 5.7 cents per kW so I'm not complaining. I believe up in Chicago they offer TOU pricing. I like what I have. I don't have to worry about when I charge.
 

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This is a single meter whole house time of use plan if I understand your post. Shame on the utility and the Public Service Commission for inventing this monster. You will forget about saving all that money most of the year when you are trying to decide to turn on the AC at 4pm in July. Wholesale price of electricity in the upper mid-west is less than 2 cents at night. There is no reason to offset with higher rates during the day.
I think these plans are the future for all electric users. They are just trying to get volunteers now.
Unlike much of the country the upper mid-west doesn't air condition that much. If your AC and house are reasonably efficient this plan will probably be a winner for almost every day of the year. EVs take less to charge in the summer as well.
Having 2 EVs will increase the savings. Electricity is still cheaper than gasoline around here.
 

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Discussion Starter #5
This is a single meter whole house time of use plan if I understand your post.
If your AC and house are reasonably efficient this plan will probably be a winner for almost every day of the year.
That's correct, whole house is on a single meter.
Yes, house is 3 years old and pretty efficient AC unit, etc.
 

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At first glace, I'd think the EV plan would be likely to save you some. My back-of-the-napkin calcs have an average rate of $0.112 with the EV plan and $0.139 with the existing plan. But it would depend in part on how power-hungry your household is during those 2pm-6pm hours in June-Sept.

If you'd be willing to program your thermostat to run the A/C a bit harder and cool the house a few degrees before 2pm, and then raise it by maybe 3-5 degrees warmer during those peak hours before lowering it again a few degrees at 6pm, that would help to minimize demand during that peak period.

Also, if you use more power during weekends, that would help too. I know I tend to do laundry on the weekends. And I run the dishwasher at night. (I'm on a variable TOU plan.)
 
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