Those in So. Cal...What has been the worst month for solar & what was your bill like?

[MikeInRialto]

I'm in So. California and if you are too, what has been your worst month, the bill for that month, and of course the size of your system.


Thanks!

[J.P.M.]

I'm in So. California and if you are too, what has been your worst month, the bill for that month, and of course the size of your system.


Thanks!

The billing for any 30 day or so billing period will also depend on usage as well as generation. A more meaningful parameter might be total generation for the period in kWh divided by system size in STC Watts or kW. For example, I could have lousy generation and be gone for half the month, or great generation and a mild month w/ little/no HVAC load, etc.

Not sure what use a comparison of bills against generation by themselves might have. Maybe use minus generation as a way to help determine if/where more conservation efforts might be helpful, but since conservation efforts are best made before system acquisition, and while still useful, if the offset is > 100%, that's sort of closing the barn door after the horse got out.

[rhedayi]

I have a 5.2 kw SP system, worst month WAS december at 532 kw but this month is only at 432 with 2 days to go and rainy cloudy weather coming.....last month the bill was $85 TOU DT plan

[NorCalX]

Have you figured out how to use PVWATTs yet?

The month by month performance prediction tells you when to expect the worst/best solar generation months (does all the seasonal/weather pattern etc. stuff for you).

For my location in Northern California it is January (I can expect approx. 395kwh in Jan but 1402kwh in Jun)

When I checked a randomly SoCal location in San Diego it was December (my system would expect approx. 700kwh in Dec but 1200 in July)

PGE lets us check our historic usage. Check if SCE does as well.

If so you can compare your historic electric usage per month against the performance prediction and get a rough estimate of what to expect

And for some real world results...my JAN production with 1 more day to go is currently at 368.5/395. If I get 20-26 as expected for the current weather I will end slightly below the estimate with 388-394ish out of 395. Not bad considering "el nino" and tons of rain so far

[J.P.M.]

Have you figured out how to use PVWATTs yet?

The month by month performance prediction tells you when to expect the worst/best solar generation months (does all the seasonal/weather pattern etc. stuff for you).

For my location in Northern California it is January (I can expect approx. 395kwh in Jan but 1402kwh in Jun)

When I checked a randomly SoCal location in San Diego it was December (my system would expect approx. 700kwh in Dec but 1200 in July)

PGE lets us check our historic usage. Check if SCE does as well.

If so you can compare your historic electric usage per month against the performance prediction and get a rough estimate of what to expect

And for some real world results...my JAN production with 1 more day to go is currently at 368.5/395. If I get 20-26 as expected for the current weather I will end slightly below the estimate with 388-394ish out of 395. Not bad considering "el nino" and tons of rain so far

PVWatts provides an estimate of long term average performance. It is a tool for preliminary design. it is not a predictor of performance over short term periods such as a month or a year, any more than weather can be predicted. Summer PV performance will be better than winter performance for the same reason summer weather is warmer than winter weather - there's more solar energy available and it hits the ground or panel in a more vertical fashion.