Official California PG&E Thread

[planet4ever]

So once they read the meter and determine that 18/66 (~27%) of my usage was off peak and the rest part peak, they just apply that percentage to each tier. 27% of tier 1 usage is off peak, 27% of tier 2 usage is off peak, etc. So you don't have to measure baseline usage across time periods.

Yup, exactly as Rat said.

[frede]

So once they read the meter and determine that 18/66 (~27%) of my usage was off peak and the rest part peak, they just apply that percentage to each tier. 27% of tier 1 usage is off peak, 27% of tier 2 usage is off peak, etc. So you don't have to measure baseline usage across time periods.

Yup, exactly as Rat said.

Thanks for the clarifying, that makes sense.

[frede]

Fred,
You are welcome here, and we are happy that you have chosen to participate.
When will you get your Volt?
Merry Christmas

Thanks for not kicking me out! My Volt is in transit by rail from Michigan. I've heard that it might be here (SF Bay Area) by tomorrow, but I'm not holding my breath. There is a very active thread over at gm-volt.com forums about people tracking their Volts, and the rail shipments seem to be moving at a snail's pace. GM shipped the first few Volts by truck so there are some in CA that have already received their Volts (and their tax break), so you might see one on the road.

[Ready2plugin]

Fred,
You are welcome here, and we are happy that you have chosen to participate.
When will you get your Volt?
Merry Christmas

Thanks for not kicking me out! My Volt is in transit by rail from Michigan. I've heard that it might be here (SF Bay Area) by tomorrow, but I'm not holding my breath. There is a very active thread over at gm-volt.com forums about people tracking their Volts, and the rail shipments seem to be moving at a snail's pace. GM shipped the first few Volts by truck so there are some in CA that have already received their Volts (and their tax break), so you might see one on the road.

Fred,
Congrats on the upcoming delivery of your Volt! My LEAF should be here by Jan 5. I'm in the camp of the more EV/Plug-ins the better! Can I ask if you were able to get your Volt at or close to MSRP?

Thanks!

[garygid]

Fred,
What EVSE ("charging dock") are you planning to use?

What is supplied with the Volt?

Is it the "Voltec" EVSE from SPX, or what?

Thanks, Gary

[greenleaf]

So once they read the meter and determine that 18/66 (~27%) of my usage was off peak and the rest part peak, they just apply that percentage to each tier. 27% of tier 1 usage is off peak, 27% of tier 2 usage is off peak, etc. So you don't have to measure baseline usage across time periods.

Yup, exactly as Rat said.

I sat down to create a spreadsheet to compare E1, E6 and E9a. I have a question regarding how the percentage usage for peak, part-peak and off-peak are calculated.

For simplicity, let's talk about winter with only part-peak and off-peak. If my part-peak usage for the month is 10 kWh and off-peak uage is 20 kWh, then my usage percentage would be easy to compute:

Part-peak 33%
Off-peak 67%

We get 33% from taking 10/(10+20) = 33%.

What about if my part-peak usage is -5 kWh (net generation from solar PV) and off-peak usage is the same 20 kWh? How would the percentages be computed?

Would it be the following?

Part-peak = 5/25 = 20%
Off-peak = 20/25 = 80%

I am guessing that the denominator would be abs(-5) + abs(20) = 25 since if I do not take the absolute value, I would end up with a denominator which is zero if there generation = consumption.

Can anyone please comment?

[planet4ever]

No, no. Not at all. If your total usage is less than your baseline then all of your usage, positive or negative, is tier 1. You don't want to use absolute values for anything. In this case just multiply the actual kWh for each period by the tier 1 rate for that period. The answer, positive or negative, is what you are charged or credited.

Actually, now that I think about it, my spreadsheet does the same thing with multiple tiers. What I really compute is the percentage of total usage that falls into each tier, and then, within each period (peak/part/off) multiply the signed kWh for that period by all of those percentages and add them together to give the total charge or credit for each period.

I use IF(..;..;..) logic to calculate the percentages, so I would not end up dividing by zero even if my total usage was zero (which it never has been). For example, my formulas for the tier 1 and tier 2 fraction cells are, in effect:
Tier 1 fraction: IF(net<baseline;1;baseline/net)
Tier 2 fraction: IF(net<baseline;0;MIN(net-baseline;0.3*baseline)/net)

[greenleaf]

No, no. Not at all. If your total usage is less than your baseline then all of your usage, positive or negative, is tier 1. You don't want to use absolute values for anything. In this case just multiply the actual kWh for each period by the tier 1 rate for that period. The answer, positive or negative, is what you are charged or credited.

Actually, now that I think about it, my spreadsheet does the same thing with multiple tiers. What I really compute is the percentage of total usage that falls into each tier, and then, within each period (peak/part/off) multiply the signed kWh for that period by all of those percentages and add them together to give the total charge or credit for each period.

I use IF(..;..;..) logic to calculate the percentages, so I would not end up dividing by zero even if my total usage was zero (which it never has been). For example, my formulas for the tier 1 and tier 2 fraction cells are, in effect:
Tier 1 fraction: IF(net<baseline;1;baseline/net)
Tier 2 fraction: IF(net<baseline;0;MIN(net-baseline;0.3*baseline)/net)

Thanks. I think I have got it figured out now.

After I put in my (expected) consumption and Solar EV generation data, here's my cost summary (30 days):

Code: Select all

                     E1      E6     E9a
Winter without EV  $28.45  $30.70  $25.04
				
Winter with EV     $66.35  $61.05  $43.52
Summer with EV     $43.07  $22.48  $35.18
Mean (with EV)     $54.71  $41.77  $39.35

I have included a 30-day meter charge of $7.59 for E6 and $6.56 for E9a.

When I get my Leaf, E9a is better in winter while E6 is better in summer. I think I should move to E6 or E9a. I will have to eat my words from several post earlier in which I said I will stick to E1.

[Ready2plugin]

Good news, PG&E has a new rate analysis tool that they will run for you over the phone that will put in what type of EV you have, number of miles you estimate to drive per year and it will compare your current rate with E9a or E9b to see which would be best given your usage history. I found out the my solar company was wrong for keeping me on E1, my cost will actually drop an average of $10 month from my E1 rate (without the car) to the E9a rate (with the car). Don't call the main number but their 877-743-7782 (new construction) number if you want them to do the same for you. They are also going to run an analysis using the E6 rate, but that takes 7-10 business days, so I'll see if that is actually better before I switch.

[greenleaf]

Anybody knows how frequently (or infrequently) we can switch rate schedules?