New system config in Bay Area

[DanKegel]

$3.38? Choice seems pretty easy

[J.P.M.]

$3.38? Choice seems pretty easy

Only easy for those who only look at first cost.

[Willaby]

Again, you are demonstrating that you haven't actually modeled realistic consumption patterns against the current and proposed TOU rates.

Of course I have, I have a simple spreadsheet for it. I ran it for 38c and 45c under a 4-9 peak scenario. I consistently use 22c and 18c for off and super-off as I think these rates are reliable assumptions. With a "right-sized" system, which I now suggest is around 120% (for my situation), you can efficiently generate some credits in winter to carry to summer AND the mid-day summer production will help offset that later peak. A 60-70% system comes up short.

Under the current peak I am looking at $400-500 in credits (potential for a 2nd EV), after the shift I might have $100-200 in credits. I think I used a realistic model, including changes in consumption (washing after 9pm instead of 6pm, etc).

Tell me you don't think many SDGE solar customers will be in for a shock after the peak shifts.

Btw, "right-sized" for me includes 10% for degradation. Estimated 8% per decade? I want to cover at least half this over the life.

[Willaby]

150% of usage qualify for payback in 10 years? possibly but clearly the 50% over production will take longer to pay back than the 100%
and that is IF you are allowed to interconnect 150% under net metering. (big if)

Of course. My point is that if a poster comes to this forum and asks for advice on system size and they get an answer that it needs to payback in 10 years, that is just not much help and not good advice.

[Willaby]

Not to mention if the POCO's can get the net metering payback reduced like they did in Nevada.

IMO it is a gamble to purchase a system that over produces with hope of getting back that investment based on how much my extra generation is worth to someone else.

Maybe in CA where the rates keep going up and the people keep complaining about it but do nothing to stop it.

Heck, my POCO is Duke Energy and it is now considered the worst electric utility in the country yet my rates are now ~ $0.095/kWh for the 1st 1000kWh which is lower then they were 8 years ago. It is hard to complain about that cost which unfortunately makes it real hard to justify installing a personal solar pv system. The payback could exceed 15 years in most cases.

I don't think they can reneg on California NEM, at least that is a fixed assumption in my model. California is unique, and San Diego is most unique. After the shift I think peak rates may actually drop for a time and Sensij might even agree with this (?). I use rates between 36c and 50c (they are 48c now).

I have a friend in Beverly Hills, FL, loves solar, huge house with a huge roof, but will never buy it as long as the kwh rates are so low.

[Willaby]

I didn't see any name calling. Where was it ?

You have to look hard.. Remember, I'm a sensitive guy with a thin skin.

[DanKegel]

Only easy for those who only look at first cost.

Well, that'd hurt if it were true. But since you didn't bother to say why it was inaccurate, I assume you didn't want to be taken seriously.

The choice was between SolarEdge and Enphase, I think.
If the SolarEdge is $1500 cheaper and can handle the load just as well, I'm pretty sure that the SolarEdge will be the better choice of the two. SolarEdge's simpler module electronics seem likely to be more reliable.

[J.P.M.]

I don't think you should ignore TOU because that's likely the best plan for you if EV charging is significant portion of the your electric usage. Modeling using tiered rate plan won't be accurate. I have PG&E and EV and switched to EV-A. The modeling result is quite different from tiered rate plan. Also, PVWatts model seems to be only accurate within 20% (a big range) due to weather variation (El Nino seems to have impacted my solar production significantly). On top of that PG&E changes rates to complicate things further. For example, the most recent PG&E rate changes increased partial-peak and peak rates significantly which increased my NEM credits significantly since I export most of my solar production during partial-peak and peak hours even though my overall solar production has been significantly below PVWatts model. So, it's looking like I will get to using a lot more A/C in the summer for free. All in all, I don't think it's practical to project with high accuracy given all the variables. Lastly, I think you can get better pricing for LG/Enphase in the Bay Area.

With the idea that PVWatts is a long term average estimate with any year off by a fair amount, do you have any thoughts on other reasons why production might be down besides perhaps El Nino ?

[J.P.M.]

You have to look hard.. Remember, I'm a sensitive guy with a thin skin.

Yea, me too.

[activemind]

Thanks for the responses everyone...

But if we ignore tge $1500 differnce and just look at the reliability and features of the system...

Would you guys still recommend solaredge?

[J.P.M.]

Of course. My point is that if a poster comes to this forum and asks for advice on system size and they get an answer that it needs to payback in 10 years, that is just not much help and not good advice.

I use 12 years, but I believe I'm a bit on the long side. How long does the average homeowner shopping for solar plan to stay in their home ? I read/heard somewhere folks average stay in a home in the U.S. is ~ 7 years. I'm also wondering if in 10 - 12 years, there might not be some whiz- bang stuff that makes solar obsolete. Maybe a higher probability in 15-20 yrs.

Given the idea that people scrap out $500 phones after 2 yrs. for no reason I can decipher, I don't have a hard time with 10 yrs. on a PV system. Besides, 10 years is a conservative guess that makes for sharper price hunting that will get about a SWAG 10% ROI and anyway, not a 25 year anything can be cost effective time frame from the solar peddlers and tree huggers or the solar will never be competitive on the other end from some anti solar rightwing blowhard. It's a guess, and a starting point, or some attempt at a beginning point for a rational cost analysis.

[SunEagle]

I don't think they can reneg on California NEM, at least that is a fixed assumption in my model. California is unique, and San Diego is most unique. After the shift I think peak rates may actually drop for a time and Sensij might even agree with this (?). I use rates between 36c and 50c (they are 48c now).

I have a friend in Beverly Hills, FL, loves solar, huge house with a huge roof, but will never buy it as long as the kwh rates are so low.

I hope you are correct that the POCO's can't change the game like they have in other states.

[J.P.M.]

I hope you are correct that the POCO's can't change the game like they have in other states.

I'd bet they can, but given the visibility of solar both as a physical and social presence, and the pubic comment such a move seems likely to evoke, I'd guess it's less likely (but not impossible) that any of the NEM rules currently in place in CA will suffer grandfather to be euthanized.

[SunEagle]

I'd bet they can, but given the visibility of solar both as a physical and social presence, and the pubic comment such a move seems likely to evoke, I'd guess it's less likely (but not impossible) that any of the NEM rules currently in place in CA will suffer grandfather to be euthanized.

My concern is that Nevada has already changed the Net Metering rules and now the Pennsylvania PUC wants to do the same thing.

[activemind]

After much deliberation and back and forth and 16-18 configs/quotes later I think I have made up my mind

I am going with 18 LG320 panels and SE P300 power optimizers and SE7600 inverter.

Total system power would be 5.76kW and price would be $19,465 => $3.38/Watt.

After rebate cost ~ $13,625.

I am also doing my panel upgrade from 100A to 200A as part of this project.

Had some questions about that:

1. What panel should I be putting? I dont want the best in class but I want best bang for the buck and good saftey rating.
2. I will be putting 1 240V outlet for charging my car at home. Anything special I need to keep in mind when the circuit is wired?

Thanks for all the feedback and help guys.
Appreciate it!

-AM

[ktran1]

Hi activemind, how much does it cost to have panel upgrade from 100A to 200A. I live in Bay Area, it will cost me a lot of money >$10k to upgrade to 200A because they need to trench and pull copper wire from PGE box to my meter. Thanks

[activemind]

@ktran - the simple answer is depends.

There are 2 parts to a panel upgrade.
1. The panel itself (100A bus bar vs 125A vs 200A)
2. The wires from transformer TO your main panel.

1. It should cost you ~2k for upgrading to 200A. I got multiple quotes and finally decided to go with the guys who were doing the solar connections because they turned out little cheaper since they were there anyways.
2. I got lucky here that my line was already 200A. You have to talk to PGE and they need to send someone out to be able to answer this but all of this should be no cost to you. If there are conduits or aerial wires, then upgrade would be cheaper. But if they have to re-trench then I would say > 10K.

So I would start by calling PG&E and asking them to evaluate your line. Have your latest bill handy.
Best of luck!

-AM

[ktran1]

Hi activemind, thank you for your response. My house is 43 yrs old, the PG&E box is located underground on my sidewalk direct to meter about 25 ft. I know the wire feed to my meter made by aluminum, which has 125A rating. From the meter, there is 100A relay feed to sub-panel 125A rating in garage. I wonder if the wire was buried with or without conduit. I signed a contract with solar installer, they will take care everything. I think they will do a simple upgrade panel from 100A to 125A.