New Solar Install in San Diego TOU with EV

[sensij]

Your situation does not sound very different than mine. I just completed my first month under EV-TOU2 and it is working out very well for me. I just posted some numbers here, but the executive summary is that with TOU, my 3.1 kW system is on track to produce enough to cover 600 kWh of monthly demand, split about 55%/45% between baseline usage and EV. In this first month, if I had been on the tiered plan I would have had a $15 bill. Not bad right? With TOU, instead I had a $46 credit that will be used in winter when the array won't produce enough.

Offhand, I'd guess that a 4 kW - 4.5 kW system would be enough to cover your bill under TOU, but there are some caveats. Where in San Diego are you, and what is your roof orientation and pitch? EV-TOU2 has a very solar friendly 12 pm -6 pm peak period right now, which is likely to turn into 2 pm - 9 pm at some point in the next few years. I can share a spreadsheet that shows some whatifs, although it is helpful if you download your "green button" data from SDG&E's website so that you have a reliable consumption history to model.

[cmarschi]

Thanks to all of the key people on the forum that provide invaluable information and feedback for newbies like myself who are trying to learn more about solar.

I am just starting the learning process and have done some initial runs on PVWatts. I have a couple directional questions that hopefully you can help with.

My Non-EV electric usage is very low, approx. 400-500 KWh a month. With the EV in the last two months my total usage (now on TOU) is 750-950 KWh per month.

My first estimate was for a 5.4 KW system that would cover essentially all of my electric consumption. The choices are for the LG panels or the Sunpower. I will read more on those options in the other posts. It seems most of the more diligent members are using or recommending the LG panels.

It seems like a smaller system may make more sense for my situation. My EV is fairly inefficient and my expectation is that for the next three years I will be under 1000 KWh per month in usage. If I get a new EV, it will likely use less electricity and we would be unlikely to have 2 EVs in the household any time soon.

Any thoughts on the calculations I should use to determine the system size when using TOU where an EV is the primary driver of usage? We do not have airconditioning and are not typically home during the day. My peak usage rate on TOU is less than 100 KWh per month.

Any feedback or direction would be greatly appreciated.