Adding more panels to existing system advice welcome

[MGE]

Morning gents been a while since I posted up here and I'm looking for some advice on adding to my existing system.
I am located in San Diego Cal.

Installed ( 8.84DC system) (34) 260w Suniva ( USA made ) panels with some Enphase M215 micro inverters back in April of 2013 and have been trouble free from day one.
Have generated 120MW to date and every thing is operating fine.
This system covers about 80% of my electricity usage annually.
Looking at possibly purchasing an electric vehicle sometime in the future and want to hopefully offset the cost of charging when the time comes.

Currently have a 200a main service panel (200a buss rating and 200a main breaker ).
I have (2) 20a 2 pole breakers that are pretty much maxed out so I wont be adding any more panels to those strings.
Looking at adding possible another 4k on a new 20a 2 pole and have the space in panel to install.

Looking at installing another system on our 2nd story roof, run conduit down etc and tie into my service panel.
If I swap out my 200a main and replace it with a 175a breaker will that give me the capacity to add more solar?

Just started looking at panels and came across some Panasonic 360w units for about $350 ea. and some Enphase IQ7+ micros for about $129. What is anyone's experience with these models?

I understand that the newer micro's are not able to be monitored with the older Envoy display that I currently have but I should be able to purchase another Envoy ($500) and add a separate string on the same Enphase site to monitor the new system. Am I correct?

Been out of the game for 10 years or so since I retired (IBEW Electrical Contractor) so I'll need to brush up on any new code requirements.
Luckily I was able to install my present system before the 3' safe space requirements for roof access.

Any suggestions are welcome.

[J.P.M.]

Questions:

1.) Are you still under NEM1.0 ?

2.) NEM 1.0 or otherwise, do you know that you can add up to 1 STC kW to your system and keep whatever NEM agreement you now have ?
Add more and I'm pretty sure your NEM 1.0 status can change.

If you have not done so already, before you start making plans and spending $$, check what SDG & E has published and then call them to confirm what you believe you understand about rules for system expansion.

If you're on NEM 1.0 you can stay there until 04/2033 or at least until the law changes, and stay on tiered rates provided you stay under a 1 STC kW expansion which, given your usage and annual solar fraction is a significant advantage - at least until an EV adds something like about 300- 400 kWh/yr. to your annual usage for every 1,000 EV miles you drive.

Add more than 1 STC kW and your NEM 1.0 status can change.

I'm in 92026 and in what may be a somewhat similar situation to yours, I've got a 5 STC kW system that was installed 10/2013 under NEM 1.0.

I'm on tiered rates and plan on keeping that status as long as possible.

An EV may change those plans for me but I've got spreadsheets w/all the SDG & E rates and my average usage and generation in 15 minute or 1 hour intervals respectively since array startup and will evaluate as situations develop.

[MGE]

Not sure of my Tier rate schedule but after having solar for awhile SDGE sent me some info on changing to a different program. I declined and was grandfathered in with my existing one for I think it was 20 years or so. Yes we are on NEM.
So a call to SDGE would give me my limit on expansion?
So my original system is 8.84 KW DC, 7.6 KW AC. So I can add 1kw additional without changing?
What is STC? Supplemental Type Certificate?
Gonna call Utility now and see what shakes out.
Im in 92117.

[J.P.M.]

Not sure of my Tier rate schedule but after having solar for awhile SDGE sent me some info on changing to a different program. I declined and was grandfathered in with my existing one for I think it was 20 years or so. Yes we are on NEM.
So a call to SDGE would give me my limit on expansion?
So my original system is 8.84 KW DC, 7.6 KW AC. So I can add 1kw additional without changing?
What is STC? Supplemental Type Certificate?
Gonna call Utility now and see what shakes out.
Im in 92117.

Before I start:
1.) There's a lot of alphabet soup in this post which I try to explain, so please bear with it.
2.) I'd respectfully suggest that you might google "SDG & E + current and effective tariffs" and look under "residential rate plans available to you. Then, familiarize yourself with schedules "DR" ("Domestic Residential) and "DR-SES" (Domestic Residential - Solar Energy System) for your information ("FYI"). As you will see, ther are lots of rate plan schedule options.
3.) STC == Standard Test Conditions/ See the end of this post for more info.

Look at your bill. It will tell you what schedule (rate tariff) you're on. If you see schedule "DR" for a rate schedule, you're on tiered rates. Anything else and you're on some time of use (T.O.U.) rate schedule. Maybe/Probably Schedule DS-SES.
You have been on NEM (Net Energy Metering), which itself is a schedule, from the time you got your PTO (Permission To Operate) back in 2013.

Originally, all CA NEM eligible customer/users of the big 3 CA IOU's (Investor Owned Utilities) - SDG&E, SCE and PG&E - were on what's called NEM 1.0., the original net metering scheme in CA.
Also, many other non I.O.U.'s (like co-op's and MUD's (Municipal Utility Districts) followed the CA Public Utility Commissions (the "CA PUC") I.O.U. mandates and offered some form of similar NEM arrangement. Under NEM 1.0, most folks were on what's called tiered rates - officially called "Schedule DR" with SDG & E. That meant (and still means) that rates were tiered by usage during a billing period, that is (and oversimplified a bit here for brevity and clarity), users on schedule "DR" (tiered rates) paid (and still pay) one $$ rate per kWh for the first few hundred kWh used in a billing period and a higher $$ per kWh rate for the next tier, and so forth.

After the ~ 5 % limit of utility system capacity supplied by PV was hit for each utility, NEM 1.0 no longer accepted customers into the original fold.
But people still wanted PV and net metering. So, NEM 2.0 came along. It's still net metering, and that's good, but it has some features that make it not as good as NEM 1.0 for most users. One of the not so nice things about NEM 2.0 is that for most new NEM 2.0 customers, something called "Time of Use" (T.O.U.) rates are mandated. Those rates can be a PITA (pain in the ass) to use and usually/often have the general effect of raising the average cost of a kWh of energy for a billing period over that of tiered rates by some amount depending on billing period usage amount and primarily on the time of day when that energy is used. For example, summer afternoon rates (when a lot of high usage A/C (air conditioning) is used). Those rates are considered quite draconian by a lot of users. On the other side of the T.O.U. rate scenario, there is something called "super off peak rates which, depending on rate plan chosen, can be quite cheap. The rub there is that the super off peak rate is mostly available midnite to 6 A.M. seven days/week and additionally from 6 A.M. to 2 P.M weekends and 10 A.M to 2 PM. during March and April. So, unless someone does a whole lot of what in the vulgate is called time shifting, a lot of energy gets billed at peak time rates of 4 P.M. to 9 P.M. for non-grandfathered users.
Long story on the March and April weirdness that's left as an exercise for the student.

Anyway, and from what you write, it sounds (reads) to me that you are one of those NEM 1.0 users who actually paid attention and responded to SDG & E's letter (which letter was more/less forced on the I.O.U.s by the CA Public Service Commission) that required users to actively decline to be switched from tiered rates to T.O.U. rates. That is, if users didn't actively declare and decline to be switched over to T.O.U. rates which, by default, at least for users on NEM with a solar energy system, would be to schedule "DR-SES", they would, by their inaction, be switched to T.O.U. rates. The wording in the notification letter users got was, in my opinion, written in a sort of deceptive way, and many of the folks I spoke with about it threw it away as just a bill stuffer - not realizing that unless they sent it back declining the change to T.O.U. billing, that's exactly what would happen. Reads to me like you were one of the few who read it and sent it declining the change.

Now, what does any of this have to do with your desire to increase system size ?

Well, if you are on NEM 1.0 - and from what you write it seems you may still be on tiered rates - if you increase the size of your system size beyond 1 STC kW, you will, by the rules of the game, be liable to getting changed over to NEM 2.0. That means you may well lose your tiered rate eligibility.

Now, as I wrote above, new NEM 2.0 users are (or will be) on some T.O.U. tariff (there are some legacy NEM 2.0 users still on tiered rates but all new NEM 2.0 uses are on T.O.U.)

That's why I wrote it's important to make sure of your NEM status and whether you're on tiered rates or T.O.U. rates.
You will need the information to make more informed and perhaps better decisions about increasing system size while maybe getting an EV.
Increase system size more than 1 STC kW and you'll give SDG& E reason to pull/change your NEM 1.0 status and maybe your 20 yr. eligibility and tiered rate grandfathering, all of which they are eager to do given the opportunity which you might hand to them.
Depending on your circumstances (and everyone's situation is different, believe me ) you may or may not come out ahead or behind in either case, but some homework is going to be necessary.

I enquired with SDG & E several years ago about increasing my system size by more than 1 STC kW. After getting vague answers from a couple of phone droids and a couple of links/steps up the chain of command I was told in a rather cryptic way that it "probably" wouldn't be a good idea to do that (that is, increasing my system size by more than 1 STC kW) if I wanted to keep my NEM 1.0 status and so my tiered rates, and so a generally lower cost per kWh vs. what I'd pay for the same amount of annual electric energy draw from SDG & E if I change over to T.O.U. rates.

For your case, and here's one rub and only one of several considerations you may want to learn and then think about before you do anything:
With T.O.U. rates you can most likely charge an EV at night during what are called "super off peak" hours - midnite to 6 A.M weekdays and midnite to 2 P.M on weekends for most SDG & E T.O.U. residential rate schedules for a lot less $/kWh than with schedule "DR" - that is tiered rates. Reason: All the extra electricity an EV draws on a tiered rate schedule is most likely charged at the higher tiered rate that's maybe 2 or 3 times as much as the "super off peak" T.O.U. hourly rate. But, you'll have a lot fewer billing surprises on tiered rates, and maybe lower overall annual bills, particularly because of those draconian summer "on peak" T.O.U. rates.

I'd respectfully suggest that being informed about what the costs and consequences of increasing your system size may be something you might want to consider.

All this stuff sounds complicated, and it is, but it's more convoluted than complicated and it is understandable with a bit of diligence and perseverance. Just don't expect SDG & E to be very helpful, forthright or forthcoming with information. FWIW, I've found a persistent but professional and maybe pleasant attitude helps in getting information.

BTW: STC = = "Standard Test Conditions". That's how PV panels are tested or "rated". A panel is put normal (perpendicular) to a solar simulator that has an (artificial) irradiance of 1,000 W/m^2 while being held at a temperature of 25 C. and no wind velocity. Thae panel's power output at those conditions is then measured. Whatever power output the panel produces under those conditions is the panel's STC rating. Usually, that's done (verified) with something called a "flash test" on a production line making it easier to keep the panel (actually the solar cell temperature) closer to 25 C. and also to lower the cost of testing.
I usually specify "STC" watts for clarity and completeness and to avoid confusion. There are other rating methods which, IMO (in my opinion) only, do little more than muddy the water as to what people are buying and so are worse than useless. Still, those other ratings persist, and while many folks know what a, say, "250W panel" means, I'm specific about which rating I'm referring to.

Take what you want of the above. Scrap the rest.

[MGE]

Spoke to an SDGE rep yesterday and they confirmed what JPM stated. Anything added over 1KW kicks me out of NEM.1.0 and over to NEM.2.0 rates.
So I will be researching those rates and compare them to my existing. As soon as the wife tells me the password to our Utility account, which she has changed numerous times so I don't have access to that yet.
She's home, stay tuned.

NEM1.0 sure looks better than 2.0 which is better than the 3.0 thats coming up next.
Went back and looked at my 2021 statements for the year and I averaged, after credits of course, $72.44 per month in Electricity charges over a 12 month period.

Looking at my 8 1/2 yr history my average cost per month was $91.70.

Looking like I will probably stand pat on adding any more panels as the payback on my estimate for a 4kw ststemat around 7k all in will take a long time to realize.
Now maybe in 2033 when my 20 year grandfathered NEM1.0 account is due I'll see what will be the smartest choice to go then.

Thanks for the help JPM.

[J.P.M.]

Spoke to an SDGE rep yesterday and they confirmed what JPM stated. Anything added over 1KW kicks me out of NEM.1.0 and over to NEM.2.0 rates.
So I will be researching those rates and compare them to my existing. As soon as the wife tells me the password to our Utility account, which she has changed numerous times so I don't have access to that yet.
She's home, stay tuned.

NEM1.0 sure looks better than 2.0 which is better than the 3.0 thats coming up next.
Went back and looked at my 2021 statements for the year and I averaged, after credits of course, $72.44 per month in Electricity charges over a 12 month period.

Looking at my 8 1/2 yr history my average cost per month was $91.70.

Looking like I will probably stand pat on adding any more panels as the payback on my estimate for a 4kw ststemat around 7k all in will take a long time to realize.
Now maybe in 2033 when my 20 year grandfathered NEM1.0 account is due I'll see what will be the smartest choice to go then.

Thanks for the help JPM.

You are most welcome ; my pleasure Sparky.

What's your array's orientation ?

[Ampster]

MGE
With regard to your assumption that you will be grandfathered on NEM 1.0 it may be at risk with NEM 3.0. I don't have specifics because the NEM 3.0 proposal has changed numerous times. My advice is to read the latest as it evolves.

[MGE]

Array's orientation is.

(17) panels facing S at 22 degree tilt.
(6) panels facing W at 12 degree tit.
(11) panels facing W at 5 degree tilt.

Not optimal but ascetically not noticeable.

I am already grandfathered in until 2033 from what I understand unless something changes that I wont have control over.

[Ampster]

.........
I am already grandfathered in until 2033 from what I understand unless something changes that I wont have control over.

My point was that your assumption about being grandfathered is subject to a change that you may not have any control over. But you may have control over a strategy to mitigate the risk of being thrown into NEM 3.0 sooner than expected. If you are already into NEM for fifteen years then you may automatically be thrown into NEM 3.0 when it becomes effective or 15 years after your PTO. I used the word ,"may" because none of us can predict how the final version will turn out. However one of the many objections to earlier drafts of the proposal was the disregard for previous grandfathered tariffs. It is worth investigating to verify whether your assumption about 2033 is still valid.

[J.P.M.]

Array's orientation is.

(17) panels facing S at 22 degree tilt.
(6) panels facing W at 12 degree tit.
(11) panels facing W at 5 degree tilt.

Not optimal but ascetically not noticeable.

I am already grandfathered in until 2033 from what I understand unless something changes that I wont have control over.

Are you interested in reasonably good long term estimates of annual output for each array and what each output is approximately worth per installed STC kW to offset a bill on schedule DR-SES and on schedule DR ?

I'm in La Quinta at the moment but I'll be back in San Diego with access to my stuff in a couple of days.

[Will792]

Prices you listed for Panasonic panels and IQ7+ are on the high side. I replaced my original system with 21 Suniva 260W panels and M215s with one using 20 original Sunivas, 52 330W LG panels and 72 IQ7s. LG panels were $200 and average for IQ7s was around $75 ($1300-$1400 for a box of 18). Prices went up a bit since I did my installation couple of years ago but not to the level you mentioned.

BTW Panasonic panels are 96 cells with higher voltage so IQ7+ is not compatible. I think only IQ7X is.

IQ Envoy uses different signaling so equipment from different generations cannot communicate. In my case I sold my original M215s and cable on eBay. New system is all IQ so no compatibility issues. Since IQ does not require neutral wire it helps with conduit wiring. One of IQ7s died after a year and Enphase sent me a replacement. Took about 2 weeks and I had to send in failed unit.

Technically you do not have to install IQ Envoy but in that case you will not have monitoring functionality. If you do install IQ Envoy it would be a new system for Enphase, without any connection to the system you currently have.

[MGE]

Thats my understanding as well concerning the IQ7+ micros that the system would be separate from my existing one as the 2 systems are not compatible together.
Put in new micros, install new Envoy, set up new array on Enphase website and monitor as I do my existing system.

The prices I got at the Wholesale house here in town Im sure was for general public pricing. I used to have a business account here as well as purchasing all my Solar system equipment when I installed back in 2013. I have friends that have accounts there if and when I was ready to go forward so I'm sure the price would drop accordingly.

I thought the Panasonics were 96 cell too and I questioned the salesman on the micros being compatible as I think their rated for 60-72 cell panels and he said no the Panasonics are 72cell.

Just goes to show you don't believe everything someone tells ya.
Trust but Verify.

JPM I appreciate the offer but as far as a long term estimate goes Im fine with looking at my Enphase lifetime graph reports. I still record my monthly Estimated/Actual energy produced.
I've been online since April of 2013 and typically overproduce in the summer months and underproduce in the winter.

Production:
2013 (8 1/2 mos) 9.8MW
2014 13.27MW
2015 12.50MW
2016 12.90MW
2017 12.31MW
2018 12.70MW
2019 12.47MW
2020 12.35MW
2021 12.71MW

With varying weather conditions I think it would be hard to track panel output production.

[Will792]

Enphase IQ microinverters compatibility with panels has to be checked with compatibility calculator, https://enphase.com/installers/micro...ers/calculator . Now there are so many different variations of panels, 60, 72, 120,144, 156 cells and so on. Even some 60 cell panels are not compatible with IQ7 in cold climates, because of voltage.

My point is to check Enphase calculator, before buying microinverters.

So many people were so excited before IQ8s were released since it can form microgrid. Now IQ8 is out and people realize that it does not make any difference for almost all installations.

You might consider line side tap for PV feed, instead of main panel feed. The other option is to install Enphase ATS before main breaker panel, even if you do not plan to use Enphase batteries. Personally I have Tesla PowerWalls with Tesla Gateway (ATS) and very happy with setup. Unfortunately Tesla no longer does PWs installation without solar so it is not an option for you.

[nomadh]

Anyway, and from what you write, it sounds (reads) to me that you are one of those NEM 1.0 users who actually paid attention and responded to SDG & E's letter (which letter was more/less forced on the I.O.U.s by the CA Public Service Commission) that required users to actively decline to be switched from tiered rates to T.O.U. rates. That is, if users didn't actively declare and decline to be switched over to T.O.U. rates which, by default, at least for users on NEM with a solar energy system, would be to schedule "DR-SES", they would, by their inaction, be switched to T.O.U. rates. The wording in the notification letter users got was, in my opinion, written in a sort of deceptive way, and many of the folks I spoke with about it threw it away as just a bill stuffer - not realizing that unless they sent it back declining the change to T.O.U. billing, that's exactly what would happen. Reads to me like you were one of the few who read it and sent it declining the change.


t.

Thanks for the amazing post. I think I remember this letter or something like it. I called to confirm nothing did or was changing and they said it wasn't but I don't recall sendeing the letter in. And I wonder if I didn't use the exact wording required. Is there something I should look for on the bill to make sure sdge didn't slam me? Thanks

[Calsun]

We recently bought a plug-in hybrid and it is set to charge from 11pm to 3am as needed. We charge the car about every third day. When there are free public charging stations we make use of them when practical to do so. We do not need more power through the panel as there is no overlap between the charging and normal household electrical use.

I would try to determine the likely power needed during the month for charging an electric vehicle as a starting point. In our case we chose to go with a plug-in hybrid that can go 45 miles on battery power before the gas engine is needed (powers the car and recharges the main battery at the same time). A 100% EV would need 4x as much power to charge and has a limited range and most EVs have no space left for a spare tire. If you get a flat tire then a flat bed tow truck is needed to take you to a tire store, which is hopefully nearby and open for business and has the tire your vehicle needs. The plug-in hybrids qualify for tax credits and allow for the HOV lanes on the freeways so a good choice at this point with current battery technology.