planet4ever wrote:Rat wrote:frede wrote: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?