~5 kW System in San Diego

[jakepv]

Looks like the ideal TOU pattern would be to limit or have no consumption during on-peak hours and shift major consumption to off or super off-peak hours per the chart linked below:

http://www.sdge.com/clean-energy/ev-rates

This is good stuff!

[J.P.M.]

With SDG&E, you can download the per-hour usage data from their website. If you're good with spread sheet, you can superimpose that with different TOU plans and see if it makes sense. Even without EV, if you can shift bulk of your usage (eg. electric dryer, AC etc) to the cheapest hours, it might still work. Also the orientation of the panels becomes more important with TOU as well.

Lots of fun but doable. Just keep in mind that use patterns are just that - and not locked in...........................On the array orientation: The optimum orientation shift to max out system REVENUE is a function of the T.O.U. pricing and time schedule rather than usage. A certain orientation will produce a value of the revenue independent of a usage pattern. Around here, that optimum is somewhere around 195 - 205 deg. az. and about 30 deg. tilt. That's mostly an academic exercise, because most arrays are parallel to a roof fixed surface. Basically, for T.O.U. array sizing optimization, run PVWatts for all the orientations you have and, for any array size, pick the one that maximizes REVENUE, not necessarily PRODUCTION.

[thejq]

With SDG&E, you can download the per-hour usage data from their website. If you're good with spread sheet, you can superimpose that with different TOU plans and see if it makes sense. Even without EV, if you can shift bulk of your usage (eg. electric dryer, AC etc) to the cheapest hours, it might still work. Also the orientation of the panels becomes more important with TOU as well.

[J.P.M.]

1) 8,400 kWh
2) 8,472 kWh
3) TOU seems to be a bit of a gamble to me since my understanding is that you can only opt in/out once a year. An installer told me that TOU is recommended for folks with electric cars (which is not me). I work from home during the day and my wife is a stay at home mom so I don't think TOU makes sense for us, would you agree?

Thank you. On #3, T.O.U. may or may not make economic sense for everyone. That's why it takes a bit of analysis. ONE consideration that usually tips the balance to T.O.U. is the ability to charge an EV at super off peak rates. It is not the only consideration.........................If you want to do the homework, and can get a fairly decent guess on your usage PATTERN, you may find (or maybe find to the contrary) that energy generated under a T.O.U. tariff is, on average, worth more/kWh than the cost paid per average kWh of energy used, allowing a smaller system to produce as much revenue as a larger system. That's were and how the initial increase in savings under T.O.U. can occur.

[jakepv]

1.) I missed the post about what your annual approx. annual electrical usage is. .................2.) Have you run PVWatts on your own yet ? If not, suggest you try it and use a 8 -10% system derate instead of the 14 % default rate, and the Carlsbab airport data.................... 3.) Sometimes, depending on use PATTERNS, using a T.O.U. pricing tariff can allow for a smaller system size to have the end result of the same $$ reduction in an annual electric bill as when on tiered rates, thus lowering initial costs even more.

1) 8,400 kWh
2) 8,472 kWh
3) TOU seems to be a bit of a gamble to me since my understanding is that you can only opt in/out once a year. An installer told me that TOU is recommended for folks with electric cars (which is not me). I work from home during the day and my wife is a stay at home mom so I don't think TOU makes sense for us, would you agree?

[thejq]

Carlsbad, SE and 20*

SE is definitely not ideal in Carlsbad (92008 and 92011 are the worst) when most of the time the marine layer doesn't disappear until late morning. Anyway you can put it on a SW roof or even partially? Like JPM said, get a good estimation on your system size with http://pvwatts.nrel.gov/ .

[J.P.M.]

Carlsbad, SE and 20*

1.) I missed the post about what your annual approx. annual electrical usage is. .................2.) Have you run PVWatts on your own yet ? If not, suggest you try it and use a 8 -10% system derate instead of the 14 % default rate, and the Carlsbab airport data.................... 3.) Sometimes, depending on use PATTERNS, using a T.O.U. pricing tariff can allow for a smaller system size to have the end result of the same $$ reduction in an annual electric bill as when on tiered rates, thus lowering initial costs even more.

[jakepv]

Where in San Diego are you ?

Which direction does your roof face ?

What kind of angle is it ?

Carlsbad, SE and 20*

[thejq]

Depending on the orientation and tilt, ~5KW is a common size (not that small) in SD area. Sunpower is a premium brand with the best warranty in the industry but with premium pricing as well. Personally I wouldn't pay more than 10% extra (eg. than LGs) for that. Both LGs and Solarworld are good panels, but LG is definitely more bankable, as Solarworld almost went BK twice. Other good choices are Canadian solar, Trina and Sunedison. If you don't have shading and want the highest reliability, I'd go with SMA and save a little money too. But if you want the best performance with panel level monitoring/debugging capability, go with Solaredge. Enphase is fine if you plan to pair with lower wattage panels, but will likely clip with the ones on your list. If you have a normal roof (tile or shingle), QuickMount system is tried and proven and trusted. As expensive as fixing the roof can be, I won't save a few bucks by using cheap mounting HW.

As for your price, $3.5-$3.75 seems to be the norm in SD without special installation requirements. Check your PM.

[albert436]

Where in San Diego are you ?

Which direction does your roof face ?

What kind of angle is it ?

[jakepv]

Good Morning all! I just discovered this forum and there's some good info, thanks for sharing. My situation is, I'm looking to purchase an approx. 5 kW system and there is no shading and a southeast facing roof with plenty of space. Three questions:

1) I think after reading a number of posts, the premium paid for Sun Power is a little too high, especially for a smaller system and no roof space constraints like I have. The two brands that keep getting proposed are LG and Solar World. What are your opinions on expected life, durability, etc.? If it was your money, which one would you buy or would it be another brand?

2) Enphase or SMA or SolarEdge? All panels will be on one side of the house and there is no shading. I get the warranty differences, I'm after quality, peace of mind, and best value for my dollar.

3) What are your experiences, good or bad with QuickmountPV vs ProSolar/TileTrac vs Unirac?

Thanks everyone and I'm looking forward to contributing to the community!


As an FYI, theses are the "best" bids I've received thus far from the 5 companies (good reviews, comparable warranty coverage, etc.) I've talked to:

5.3 KW
17x LG315 + SE5000
~$22,000
~$4.13/W

5.0KW
16x SW315 + SMA5000
~$20,700
~$4.10/W

5.2 KW
16x SP327 + SMA5000
~$24,000
~$4.58/W