drees said:
gascant said:
Hopefully the 20 kWh/day doesn't throw me into tier 5 electric rates. If it does, I might have to spend that $3500 to get a second meter installed (another thread, I know).
You're gonna want that 2nd meter if you really are charging 20 kWh/day as that alone would get you into tier 3 @ 30c/kWh, no?
Well, in the first place, he probably won't use 20 kWh/day every day, unless he's one of those crazy engineers who works seven days a week. But let's assume he does, and that his house uses both gas and electricity. I believe that makes his baseline 12.1 kWh/day summer, 12.6 winter. To get to tier 5 he then has to use 36.3 summer, 37.8 winter. So to make this really tough, let's assume the wife and kids are home all summer and using some AC, so he averages 20 kWh/day in summer without the LEAF.
I'm not sure where you got 30c/kWh for tier 3, but E1 (flat rate) is 28c. Here is what he is spending now in my hypothetical case, and would continue to spend per day for the house if he went with the 2nd meter:
12.1 kWh tier 1 at $0.12233 = $1.48/day
3.63 kWh tier 2 at $0.13907 = $0.505/day
4.27 kWh tier 3 at $0.28011 = $1.196/day
Total: $3.18/day
Note that although he is "at tier 3", most of his electricity is being billed at less than half that rate.
If he put his EV on a second meter with E9-B rates the kWh breakdown would be the same (since I am assuming the house and the car each use 20 kWh/day) but the rates are different. Assuming off-peak charging:
12.1 kWh tier 1 at $0.05995 = $0.725/day
3.63 kWh tier 2 at $0.05995 = $0.218/day
4.27 kWh tier 3 at $0.20099 = $0.858/day
Total: $1.80/day added for the LEAF
That will certainly save him money over having both the house and car on E1 rates:
12.1 kWh tier 1 at $0.12233 = $1.48/day
3.63 kWh tier 2 at $0.13907 = $0.505/day
8.27 kWh tier 3 at $0.28011 = $2.317 /day
12.1 kWh tier 4 at $0.38978 = $4.716 /day
3.90 kWh tier 5 at $0.38978 = $1.52 /day
Total: $10.54/day
That adds up fast - staying on E1 would cost him more than $1,000/year in the "summer" season (6 months) alone, and the E9-B rate would pay for that $3500 second meter cost in a couple of years.
But by moving the whole house to E9-A rates he can probably do much better than E1 without having to pay for the second meter. The problem is, you really can't figure out how much better without knowing how the house use breaks down between peak, partial peak, and off-peak times. One thing to note, though, is that in the summer season there are 35 peak hours per week, 58 partial-peak, and 75 off-peak hours, and there are no peak hours in the winter season. So those really scary 55.5c/kWh tier 4 and 5 peak rates will apply to only a very small fraction of his usage.
Ray