Tesla PowerWall2 Net Metering and 3-phase Discussion | Ludicrous Feed | Tesla Tom

[@shoimthewoim]

Thanks very much for your very helpful information. I just installed 2 PW2s on a 3 ph home and I spent a lot of time unsuccessfully trying to find this information. In my case, I have a legacy PV system on a premium FIT from 2010 or 11 and was told I needed to add the other 2 phases so that additional panels and batteries could be added without losing the FIT. When the house was switched the 3 ph, the sparkie had to balance the load across the 3 phases despite no added loads from the house (my peak load is 4-5 kW briefly and average demand is ~13 kWh/ day) so, functionally - from the grid’s perspective- I can’t see the need for the balancing. Splitting my house loads across 3 phases crueled my hope to backup the entire house (but with lights, fridge, and coffee maker (plus an extension lead to the TV) I can manage a blackout ok! And with cbus 2 smart wiring to all the lighting and exhaust fans - I discovered during a grid outage that power to fixtures and power to the control units had been split across 2 phases - so that needed to be fixed with a quick modification to the distribution board by the sparkie. I still wish I could swap all the house circuits back to the phase with the battery, seeing as how it wouldn’t make any difference to the load on that phase compared to historical use. Until I found your video, I was stressing about how I could no longer ‘disappear’ my load from the grid during the night time because there would always be some components on the non-backup phases. Eliminating my nighttime demand in order to reduce grid demand for FF generation was the whole point of my PW2 purchase as my legacy PV output far exceeded my consumption but the generation and load were not coincident. So, thank you again for putting my mind at rest!

[@LudicrousFeed]

Pleasure, glad it helped. I’ve had the same setup since this video was posted (I made this comment in Nov 2023) and everything still working fine 🙏

[@DrunkenAfro]

Great explanation. I have 3 phase & a PW2. Phase 2 & 3 are wired to run big load items only. Pool pump, ducted AC and some power tool outlets. In a blackout the house remains functional except for those big load items. This is preferable as firstly, the PW cannot discharge more than 5kw/h and if it did would drain a 100% full PW in less than an hour.

[@LudicrousFeed]

DrunkenAfro Thanks. I’ve wired my PW2 and 3-phase home in much the same way. Essentials (eg fridge and kitchen) on Phase 1 coupled with PW2/solar. TT

[@paulspeirs2]

Coming across this video late, however one point wasn't fully explained in regards to a single phase inverter and 3 phase supply through a net meter. I assume that if I'm generating 3kW and using 1kw per phase, then the solar directly powers the phase connected to the inverter, and I export the remaining 2kW. The net meter will then look at that and see that I'm importing 2kW across those 2 phases and cancel out any import costs. This only came up when the discussion included the powerwall 2. In theory it should be the same since the net meter doesn't know if a powerwall controller is deciding to send the power back to the grid or the inverter is. Cheers, Paul

[@LudicrousFeed]

Yes your summary is correct. Solar net metering occurs regardless of whether a battery is connected or not

[@craighardiman144]

Well explained Tom. From what I understand you're correct, you'd need three PW2's. Also if you're a 3 phase home and running things like 3 phase A/C etc due to their high power draw you really would need 3 PW2's, one for each phase.

[@LudicrousFeed]

Craig Hardiman I feel that way too Craig. As I said in my video, segmenting PW2 into three lots of 4.6kWh mini batteries to power a 3-phase home that is not perfectly balanced would drain the segments disproportionately. TT

[@mondotv4216]

@@LudicrousFeedIt doesn't work that way. Three phase requires three separate phases (all 120 deg out of phase with each other) and the combined voltage with a common neutral is 400V AC (not 690V) - you would need some very expensive hardware to convert a single phase supply to 3 phase (for big loads there is an autotransformer that converts the 230V to 400V, a bunch of capacitors and electronics to split that into 3 phase and an idler motor). Because the PW2 is an AC battery and it's single phase you need three of them. If it was a DC battery then you can use a single battery with a 3 phase hybrid inverter. I was very confused when you started talking about splitting the Powerwall 2 into 3 separate sections - apart from capacity it just wouldn't work.

[@gregmclean3345]

Thanks for taking the time to explain this. I have a 3 phase home where my "essential" power and lighting are spread over 2 phases. I have other non-essential devices running off the 3rd phase as well as a 3 phase bore. My Solar provider has informed me that I need 2 Tesla Gateway 2 devices to enable 2 Powerwalls to support the 2 phases of essential services. Is this correct? The rest of my setup is planned to have 36 * 370w panels and a 10kw 3 phase inverter.

[@LudicrousFeed]

Hi Greg, thanks for the question. My understanding is that for normal grid operation, if you have net metering then it won’t matter. However, in the event of a blackout, then you will want your 2 PW2/gateways connected to your ‘essential’ phases so that you are covered. Hope that makes sense. Great setup btw! 👍🙂

[@gregmclean3345]

@@LudicrousFeed Thanks for the speedy reply! So can I construe from your comment that I do indeed need 2 * Gateway 2 devices? My simple thinking was that a single 3 phase gateway 2 device should allow supply of power (using 2 powerwalls) to 2 phases. BTW I had a new (net metering) meter installed today. The only downside is that I still lose charging from the panels when the grid drops out (but I really can't afford a 3rd powerwall).

[@LudicrousFeed]

My understanding is that only one gateway is required for multiple batteries on ONE phase. I believe that backup mode is only available to ONE phase, even in a 3-phase setup and even if you have multiple batteries spread across the three phases. So I guess the issue is whether it's worth having a second battery on a second phase if it's not available for backup anyway in the event of a blackout? Again, I'm not a qualified installer so please always check with Tesla or your installer.

[@gregmclean3345]

@@LudicrousFeed Thanks Tom, it looks like technology hasn't got to where I would like it to be yet. The fundamental requirement for me; the batteries must be able to provide power to both phases at night and during grid outages. I may have to re-think my strategy or stump up more cash. Your input has been invaluable!

[@LudicrousFeed]

My absolute pleasure. Essentially we either need a true three phase gateway OR a three phase battery.

[@josephjohn907]

Nice

[@billnipp2309]

When are you getting the model 3? or are you not?

[@LudicrousFeed]

bill nipp That’s the $80k question isn’t it ... when is it coming to Australia! 😉🇦🇺

[@billnipp2309]

@@LudicrousFeed Theyre in Europe already so why not Australia

[@billnipp2309]

@@LudicrousFeed Elon Musk says Tesla's Model 3 will come to the UK and Australia by mid-2019. Elon Musk said on Twitter that Tesla's Model 3 would be rolled out in the U.K. and Australia by "around mid 2019."

[@LudicrousFeed]

bill nipp There are a lot of us in Australia eagerly awaiting their arrival. Sale in the UK will be our best indicator being the first RHD market. TT And yes we still have a reservation for the M3. 😊 TT

[@Porkonfork]

Let me tell you a story Ludicrous Feed..... 11 years ago, my 85 year old neighbor sat me down and gave me some advise. He told me to invest in renewable energy starting with my own solar panel set-up. I could only afford a 3.5 kwh system (8.2K) at that time however the back to grid cost was 60c plus an extra 6c introductory offer (total 66c) with the provider. This is guaranteed until 2023. Needless to say, l have not paid a bill for 11 years, and that includes a 4 bed/teenagers + in-ground pool/ pump etc etc. My neighbor may have passed away sadly however l am forever grateful for his wisdom and knowledge given. We would joke that when the contract finalised, we would throw a "installing battery" party along with his 100th birthday. And yes, l will do that in his honour. So...... I do hope that your wisdom and knowledge are also passed onto the younger generation. You're doing a great job... so thanks and keep it up

[@LudicrousFeed]

Porkonfork That’s a wonderful story and good on you for listening to your neighbour. If you do throw a party in his honour, be sure to send some photos! Thanks for the encouraging words, it’s viewers like yourself that keep me going. TT

[@zhenchew]

How do you get net metering? Is it a different meter or is it just a call to the power company?

[@LudicrousFeed]

zhen art Check with your energy retailer to switch over to a smart meter which can enable net metering. Some charge, others don’t. TT

[@zhenchew]

@@LudicrousFeed thank you.

[@paullewis252]

In the case of 3 phase and one battery. Assuming you do not have any appliances or tools that actually require 3 phase and the grid is down, why can't you have a contactor that disconnects the grid and connects the 3 phases on the house side, making it a virtual single phase? When the grid comes back on, the contactor can disconnect the joined phases and reconnect as 3 phases again. Yep understand the battery will be effectively split 3 ways, but if its an issue you'll have to add more battery.

[@LudicrousFeed]

AFAIK I'm not aware of a commercial product or 'contactor' that can perform this single/three phase toggle function? If so that would be awesome. As for my situation, the only 3-phase appliances are my EV chargers which is not a worry usually for me as worse case scenario I can charge my cars with the 10A mobile connector in the event of a prolonged blackout ... or go to a public charger to top up.

[@paullewis252]

@@LudicrousFeed What about a 3 phase ATS? They are readily available.

[@CNile-se9xw]

G'day Tom Love your videos, as we too are interested in reducing our power draw. We are fortunate to have a 3ph (ph = phase) solar system, with a 3ph convertor, mainly to cover our 3ph airconditioner. It works great for us, as we're retired so we run the cooler during the day when solar generation is plentiful, & it doesn't actually need to run for long due to our smallish home being well insulated. We don't have the financial resources to install 3 powerwall2s in one go, but your suggestion of starting with one Powerwall2 looks promising, even though we're aware that it won't run our 3ph cooler in the event of a blackout until we can eventually have the 3 Powerwall2s. The problem here in S Aus is that power costing computations are GROSS only, so I'm overwhelmed & wondering if it'd be cost-effective for us to go ahead, or where would be the sweet spot. Mind you, I fully realise that you're very busy & I truly appreciate the time that you've already devoted to crunching the numbers for us subscribers, so there's no expectation for you to grind it out for what would very an extremely small portion of your followers. All the very best to you, your family & those you love. John

[@LudicrousFeed]

C. Nile Thanks for your comment John. As Feed in tariffs are rolled back for solar (AGL are already starting), batteries will seem more attractive. There may be a tipping point soon. I’ll monitor market forces for now but if I see any major shifts, I’ll certainly document it via this channel. Thanks for supporting Ludicrous Feed. 👍😊 TT

[@CNile-se9xw]

@@LudicrousFeed Tom, you're a champion.

[@achung80]

i think for the 3 phase gateway to work maybe it has to have some kind of dynamic switching. so you would have say one huge bank and then 3 sub smaller battery banks that act as buffers. then your battery maangement system could potentially cycle through and discharge into each buffer battery. that way maybe you dont need to dedicate 3 large storage pools

[@achung80]

powerwall discharge is capped at 5kw from memory?

[@LudicrousFeed]

Adrian Chung That would be one smart system. That kind of bucket filling system would have to be inbuilt into the 3-P PW2.

[@LudicrousFeed]

Adrian Chung Yup capped at 5kW.

[@alex54545]

Well done my son 😅

[@LudicrousFeed]

Alex K You like that one 😊

[@ThePianoPimp]

Net