Adding panels to my installation?

mdgilford_98473756

I have a small system, 4.4kw, and I'd really like to bring it up to 6 or 6.5kw. Has anybody here ever done something like that? If so, what was your experience like? I know that I'd need a second inverter. I'm wondering about the cost of such a relatively small system upgrade. Thanks in advance to anyone who wants to share their experience.

Matt

Jones_lab_guy

Been there, done that, have the tee shirt.
Expanding a system with central inverters translates into a new install for the expansion. I've done it - twice. I started with a 4kW array (which at the time was considered impressively large). The first expansion after 5 years was to maximize the system according to local codes and I added 3 kW. They were able to attach to and expand the original rack system and essentially place the new panels around the original set so that the visual appearance is a single 7 kW array. Wiring comes down to two separate inverters and goes into two separate circuits into my breakers main box. There are no savings on the second install - it is a whole new bill of goods and labor. Second expansion after 3 more years used larger format panels and microinverters. It was again a totally separate experience and required replacing my main electrical box and a couple of code variance applications for total electrical feed and fire code for roof space and firefighter access. The third array is also a slightly different orientation.
Your experience will be dependent first of all on the installer in terms of exactly how (and if) it is integrated. My first two installs were by the same contractor so the experience each time was similar. My third install was a new contractor (who was willing to push the code envelope with variance requests).
On line monitoring is a real challenge and with each install, one of my requirements was to update the monitoring to consolidate the data.
Bottom line - a lot cheaper and easier to do it once but finances, technology and necessity can make it complicated to do it one step.
Ultimately - glad I expanded and have no regrets - my fourth install was to add powerwalls which is the icing on the cake.

gregbrew_98470014

Jones' experience is pretty common with Tesla. Each "expansion" is really an entirely separate project, with planning, permitting, and an *electrically* independent system from what was there before. Tesla won't just add panels and upgrade the inverter. A third-party installer probably would do that, and might even buy the old inverter from you, but in all likelihood, doing so would invalidate your warranty with Tesla.

rossman_98479752

I have an 11 panel 3.2kW solar city system with a 20 year prepaid lease from the house builder. This week I am adding 12 panels 4kW and a powerwall from Tesla (purchased). Will the Tesla solar app show production of both systems merged on one graph or will each system have independent graphs?

Jones_lab_guy

Tesla app will show a consolidated solar production...confirm this with your installer and via contract just to make sure. My app actually shows the consolidated output from THREE systems. (It's a looooooooong story).

gregbrew_98470014

Jones, Were all three of your systems with Tesla? If so, I can see them being able to consolidate the data. With a third-party system, I seriously doubt that Tesla can combine data with the old system, as they have no access to the old system's data, without something like a TEG.

Jones_lab_guy

All three systems were SunPower - installed at three different points over a 12 year span followed with Powerwalls as a fourth install. You are correct in that Tesla cannot access the historical info, but from the point of the PW install - yes - the output from all three of my systems are consolidated in the Tesla App.
My PWs were installed March 1, 2019. The Tesla app shows accurate production data from my three systems (consolidated) back to that date.
The only components in the mix from Tesla are my PowerWalls.

rossman_98479752

> @Jones_lab_guy said:
> Tesla app will show a consolidated solar production...confirm this with your installer and via contract just to make sure. My app actually shows the consolidated output from THREE systems. (It's a looooooooong story).

I noticed in the contract for my existing pre-paid leased panels that they have a power generation yearly guarantee for the 20 years of the lease. The guaranteed power drops slightly each year. Since it appears that after adding a new 12 panel system in a few weeks, I will see a consolidated solar output number of both the new and existing systems. How can I know if the existing system is performing up to spec if I can’t see each systems production?

I can remember some time ago folks were posting daily solar production graphs that could show multiple system outputs simultaneously on the same graph with each system being a different color.

gregbrew_98470014

Your different-colored graphs were accessed via the old MySolarCity site.

That site is no more, since shortly after the acquisition of Solar City by Tesla. We're now stuck with the somewhat less-capable Tesla app.

rossman_98479752

> @gregbrew_98470014 said:
> Your different-colored graphs were accessed via the old MySolarCity site.
>
> That site is no more, since shortly after the acquisition of Solar City by Tesla. We're now stuck with the somewhat less-capable Tesla app.

I still have the older MySolarCity app running on my phone and desktop. I like it as it can show a real-time generation graph updated every second. I suspect the MSC app will go away when my additional panels are installed next month - unless the install is postponed again from fire smoke here in northern CA.

gregbrew_98470014

Shhh! I do, too!

I also access my data through the even older SolarGuard site. The SolarGuard data matches exactly what's on the front of my inverter. The MySolarCity site data differs by less that 1%, which is weird, because it's also fed by the came Com Gateway as SolarGuard. They must handle the data in a very slightly different manner.

Yeah, you'll probably lose your Com Gateway data feed if your inverter is swapped out, unless the new one has the required ZigBee RF interface. Be sure to ask your install crew chief about it. (It doesn't hurt to ask.)

If you're getting an additional inverter, the old data should still be available, but will only tell you about a portion of your new, larger array.

rossman_98479752

The new panels will get their own new inverter so my existing inverter may still work with the MySolarCity software. Time will tell.

gregbrew_98470014

I expect that the old stuff can be integrated with the new on the Tesla app, but I highly doubt it will go the other way. Be sure to ask the installation crew chief to integrate old with new while they're on site. Getting through to Tesla Customer Service on the phone lately has been, shall we say, "problematic" for some.