Metrics for cost per KHW hour + thoughts on power optimizers vs. microinverters

[max2015]

Understood. For a good job on cost anal., a decent handle on POCO rates and tariffs is needed. Without it, you're one step above back of the envelope anal. Sometimes T.O.U. can ad to the dent over tiered rates, but it takes some knowledge of both and use patterns as f(time) to get an educated guess.

On sizing: have you run PVWatts yet ?

Hello JPM --- from a TOU perspective, we're in good shape... Since we're a working couple, the first part of PG&E's peak period (2 to 9 pm) will have little to no power draws... All of our EV charging would take place between 1 and 5 am each day...

I've run PVWATTs... The results are 14,500 kWH per year... I ran the calculator using a LG Mono Neon 300W panel.

[J.P.M.]

Hello JPM --- from a TOU perspective, we're in good shape... Since we're a working couple, the first part of PG&E's peak period (2 to 9 pm) will have little to no power draws... All of our EV charging would take place between 1 and 5 am each day...

I've run PVWATTs... The results are 14,500 kWH per year... I ran the calculator using a LG Mono Neon 300W panel.

Suggestion: Run PVWatts and download the hourly output to a spreadsheet. Then spend a few minutes loading the POCO T.O.U rates by hour into the same spreadsheet. Have patience. Multiply the output by the hourly rate for each hour of the year (8,760 hours) and sum for a yearly revenue. If that sum is more than you estimate your T.O.U. bill might be, reduce the array size as you see fit.

For situations such as yours, T.O.U. can (perhaps) be used to not only save a few bucks on the electric bill, but if considered before buying solar, can reduce the array size - Part of the benefit of delving into the POCO tariff/rate swamp.