Is AC or DC Coupling the BEST for Your Tesla Powerwall 3?

[@AliceGunners]

Informative video

[@kimlynch5526]

I have DC optimizers on my Solar Panels. They were installed in 2019. Going to the powerwall it sounds like the DC optimizers will have to be removed from each panel to work with the Powerwall 3? All 30 panels are on same plane no shade .

[@StevesTechTime]

Hi, I am currently in the process of having a modest 8 x 450W solar array on a single string attached to a Powerwall 3 fitted (currently scheduled for mid November) but due to a mix up in my roof dimensions I have agreed to a revised layout using the 8 panels but it has also now come to light two of the panels in the late afternoon sun will be affected by a shadow. Having spotted this I have agreed to having two optimisers fitted, which normally would be ideal but since I am also using the PW3 and following this video the use of optimisers looks very doubtful? I am now wondering if I should have two micro inverters fitted and have a mixed system of AC/DC (no not the band 😂)? Any pro’s, con’s, ideas on resolving very much appreciated. Just one other thing, in case I did go down the micro inverter route (whilst trying to minimise extra costs) should I split the array equally into 4 panels DC and 4 AC? Oh, one other thing, am I correct in assuming the use of a panel micro inverter, I.e. Enphase IQ 8 Plus or similar, I will not realise the full potential of my 450W solar panels?

[@sensahuma4u]

Good stuff, another useful video, thank you @Heatable. 1. It'd be good if you mention how much energy will be lost roughly if using a PV system with micro inverters, implying the Enphase would first convert DC to AC at the panel itself, then Tesla or battery system would need to convert it back to DC for storage, then finally reconversion to AC for home consumption? Considering the last step applies to all PV storage systems, would the first two steps with an Enphase system result in 8~10% loss of energy before the battery is charged? P.S- I like the Enphase based setup you guys recommend in more ways than one, but would be good if the energy losses are mentioned, howsoever big or small. I reckon the extra 10~20% production from an Enphase system with REA panels would more than compensate any loss due to extra conversion steps; is that right? 2. Have you considered Meyer Burger (German/Swiss company) bifacial panels? Thanks!

[@Heatable]

Hi, thanks for your comment. Most reference sheets report a 3% loss in conversion (each time). It's worth considering that this is only for any energy recovered from the battery which needs to be re converted so it's not 100% of the time. These losses also exist for all systems when overnight charging. We are aware of them but haven't installed them, no.

[@ngl1962]

The question I was ask when a such solar company here in Puerto Rico installed me the TESLA Powerwall one generation with a solar edge hybrid inverter and I choose DC couple but his explanation took me to fail the batteries on 2 times MARIA and FIONA that's sadly , now my one million dollar question is do you think the Powerwall one can be connected to that DC inverter of the Powerwall 3 to wake them up and maybe work with it because I can use them to setup a charging station for my car also I have Micros inverter with a GATEWAY and POWERWALL 2 how would a proper and robust setup in your opinion retro fitting a system with this equipment (5) iQ8-A , (19) iQ7-A , Gateway 2, Powerwall 2 and if I go with a Powerwall 3 with a Universal Tesla Charger, how would you setup this last two item with the ones that mention before, thank you for the responded.

[@yp77738yp77739]

That’s very useful to know about the optimiser incompatibility, thank you. Where do you find this bulletin as my installer is advising me to do this in an install in a few weeks. One question, when you process the G99 application, do you always apply for the full 11kW of the inverter capacity for exporting even if the current installation only required 7kW.

[@Heatable]

Yes we would always apply for the full 11kW to ensure we have no delays with the G99 application.

[@highland-oldgit]

My installer is also going to use separate SolarEdge inverter and optimisers due to the complex roof setup. I think this will be fine as the separate inverter will be wired to the AC side and the PW3 will only 'see' the inverter and not the optimisers ?

[@yp77738yp77739]

@ You need to question what they are doing, it’s bonkers not to use the integral inverter in the PW3. Fine to use a separate inverter but then don’t go to the expense of installing a PW3.

[@Glyn001]

Am I right in thinking that even if you had 20kw of solar connected on DC it would still only charge at 5 kw ? Secondly when the powerwall is full with this say 20kw of DC will it shut the panels off or will it discharge AC at your DNO limit to the grid . So you could have 5kw coming in and possibly 11kw going out ?

[@Glyn001]

Thank you so much for the answer this was always puzzling me and really begs the question why would you choose to connect more than say 6kw of DC unless I am being stupid and it will eg 15kw DC solar connected perfect day and generating 14kw 5 kw filling powerwall 3 and 9kw being exported DNO limit 12kw so when powerwall is full it will throttle pv to only produce its max of 11kw to be exported. If that’s how it works then it’s definitely outstanding especially for the people like myself with the original FIT who will be able to connect new DC and still keep there original AC coupled with the FIT meter separate. Thanks TOK

[@tonyt7402]

If you could only find roof space for a one of two panels for a second string, would there be enough DC voltage to activate the Inverter?

[@Heatable]

Yes that's right, even with 20kW of solar DC capacity connected, your system will still charge at the maximum rate your Powerwall can handle-typically around 5kW. So yes, even with 20kW of available DC, the charging rate is capped by the Powerwall’s input limit. Once the Powerwall is fully charged, the excess solar power will no longer be used for charging. Instead, your system will either (a) send the extra power back to the grid or (b) curtail the output from the solar array, depending on your inverter and grid-export limitations. If you have a DNO export limit (for example, 11kW), the inverter can discharge to the grid up to that limit. This means you could have the Powerwall charging at 5kW (or fully charged) while the inverter exports the surplus-potentially around 11kW if that’s your set limit-to the grid.

[@tangent2658]

Thank you for this. I was under the impression that I couldn't use a microiverter system with a powerwall 3 but I guess I can. I'm also assuming that I could mix and match so part of the solar could be DC and another section be AC. What are the costs of a G99 application and is there any way to gage the likelihood of the outcome of that application? Maybe a database of nearby homes.

[@Heatable]

Hey, yes you can have both AC and DC set up at the same time if you wanted to. G99 would be included in the installation price and it can depend on a number of factors, including how close you are to a substation and what infrastructure is in the area. Some applications take longer than others due to the local grid, but typically if you live in built up towns and cities they get approved.

[@gopakumarsudhir4766]

I have a solar system installed with a hybrid inverter and a DC coupled Pylontech battery already. I need to increase my battery storage. Can I put a Tesla Powerwall 3 in the AC coupled form alongside my existing set up to increase my battery storage? Thanks in advance.

[@Heatable]

Yes, you can add a Tesla Powerwall 3 to your existing setup to increase your battery storage, as the Powerwall 3 is AC-coupled, making it compatible with hybrid systems like yours. The Powerwall 3 operates independently of your DC-coupled Pylontech battery and hybrid inverter. It would charge and discharge separately from your current battery system, with its own inverter.

[@bringiton8989]

"Unless you have a heat pump" - it would have to be a blooming big heat pump on a very cold but sunny day for the micro inverters plus battery to be giving you a benefit - you'd be kicking out over 25kW of heat in that scenario.

[@mikec2505]

You mentioned ‘a solar show’ you were at recently. Other than Fully Charged that I am aware of, are there any other shows (preferably in the Midlands) that you would recommend that are are open to consumers like myself (rather than just trade) where we can come and chew the fat with suppliers like yourselves?

[@Heatable]

Yes we were at the Everything Electric show, but for solar specific shows, any electric, sustainability or home shows are great.

[@mazmoneth]

Hi, you’ve designed a system for me with 30 panels and a Powerwall 3. No one asked me if i have a heat pump at home,we do - and aircon! Could you clarify Bens comment on falling short of energy with a DC system as the system you have designed has no micro inverters and is DC.

[@Heatable]

Hey 🙂The Powerwall 3 can supply up to 11kw of power which should be more than enough for most domestic setups on single phase. The comment was aimed more at smaller inverters.

[@derloos]

Is PW3 really 1ph only?

[@Heatable]

Yes PW3 is currently single phase.

[@derloos]

@@Heatable meh.

[@eddierourke3878]

You can wire a PW3 per each phase. Enabling the PW3's to power a three phase home. However only one phase can be backed up off grid. So need to be careful on choosing which phase to backup, and careful of any three phase circuits. 😉