New to forum/ looking for guidance.

[lilaznjdawg]

Hi All. Newb Diyer, recently installed the eg4 mini split system with panels and now am looking for more. I currently have a 8.8kwh tesla system with 1 PW- about 50 kwh per day. However, recent and future additions, I probably need 2 more batteries and double the panels. My debate I have with myself- runs complete off grid system (looking at eg4 batteries/inverter 6000, and panels) for 15k to 20k or have tesla come back out and add a second unit for 40k and not worry about it. I installed the mini split cause I like the idea that it’s always on when the suns out. I would like to have that for two other mini splits I currently have (tied to the grid). My ultimate goal is to have the smallest grid bill while having the ac on endlessly.

The off grid system- I would run secondary connections for only some of the appliances- car charging, maybe a dryer, a the eg4 mini split plus the other two mini splits I have. Probably wouldn’t be as clean with wires going everywhere. Dependent onsize, I would run it to the main ac units (1 for upstairs and 1 for downstairs)

Adding to tesla- would be more expensive but they would be able to tie to the grid. My gripe about tesla and smud (provider) is 1. They give me .07 per kwh sent, and charge me a minimum $ .13kwh pulled. I would also have to install the new battery outside of the garage per 2022 ca code upgrade.. And charge me a $24 /mo connection fee.

To me, the easier solution would be to install the off grid system and somehow tie it to teslas system- but I’m not sure how to do that and haven’t seen it anywhere. The easiest would be adding via tesla. Anyone have any experience doing that- upgrading tesla system with out tesla? I spoke with a tesla tech and he said adding a pw is only a couple wires to the existing inverter via an app. But what if I want to add both a pw and panels? Has anyone DIY to teslas system? From my basic knowledge, couldn’t I just add solar panels to their connection box or am I missing the details.

Looking for opinions and pros and cons. I’m ok with trying new things. I’ve been watching will for some time now. Thanks for the inputs. Sorry if I’m uneducated and not looking at the whole picture!

 

[MaikaiLife]

This is a rather complicated scenario, trying to generate more solar with a black box system like Tesla, and then adding a DIY system working together without issue.

I've successfully connected an Enphase system with a Sol-Ark inverter using the Sol-Arks AC coupling feature. This feature lets the Sol-Ark run the power of the home and then by adjusting the frequency, turn the supported UL 1741SA or UL 1741 Enphase system on/off by adjusting the AC phase between 60 and I think 62HZ.

It's not ideal or very efficient, but essentially with no wiring changes to the existing micro-inverter system the Sol-Ark can couple the energy on the load outputs and use the energy from the other solar system to charge the batteries and run household loads.

This was for an off-grid application, otherwise, you need to make some wiring changes and bring the power in from your existing grid-tied system on the generator ports of the Sol-Ark.

The bottom line, it can work with some adjustments, I'm not as familiar with non-Sol-Ark inverters, but if they have the same or similar functionality then you could add a nice AIO inverter, and have it be the master inverter for your solar system, enabling you to receive from the grid, sell to the grid, AC couple your existing system and add more panels that connect to the master inverter and increase your overall solar production, plus increase your storage options.

 

[lilaznjdawg]

so from the sound of it, i probably won’t be able to as a newb to solar. would you recommend the latter, installing a new off grid system and running separate panel / plugs to appliances? or would you just pay tesla for a second system…

thanks again for all of your insight- ill have to research solar-ark and its capabilities

 

[MaikaiLife]

Given your honesty of Solar experience you would need a Solar contractor/consultant to design and implement everything, which might still have some hiccups and in the end, cost you near the same amount as adding onto your Tesla system.

It’s a tough call, but I think expanding your investment will be the most hassle free and certainly less risky when it comes to support .

 

[zanydroid]

Which NEM are you on? NEM3? Those net metering numbers are surprisingly bad. Did you validate that your numbers are correct?

The battery building code rules apply to everyone. The main difference with off grid is that it’s a lot easier to escape notice than with storage.

Also for $.13/kWh to import from grid (which is amazingly low for California), you may be looking at a rather long break even point for code compliant solar + storage if you hire someone to install. They are required by law to give you break even info though, using a simulation customized to your house.

Adding panels to the end of a string is fraught because the panels need to be oriented properly without shading. You will need someone to value engineer where to put the solar panel, relative to the input. And it is highly unlikely anyone other than Tesla will modify this for you.

There are plenty of Californians on the forum that have saved a ton with DIY grid tie and battery systems, however they really sharpened the engineering pencils to do it.

 

[lilaznjdawg]

thanks for the advice. the .13 cents is the minimum (12-6am). i believe im on NEM 2. but to my knowledge SMUD has its own? or i don’t think its applicable? I had thought in 2022 they changed their repayment. If i am in it, i believe 2.0 was around 2021 / 2022 time frame. and 3.0 was 2023.

Anyways, i would lean more towards tesla but where i want the panels would be on a roof over a porch that they may or may not install it. i would, but they probably would need the city to sign off on the structure… which haha i may or may not want.