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Finally going solar. I have a question about Enphase microinverters and Powerwall compatibility

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#21
skepticcyclist said:
You can also add a very small backup battery to avoid most of those issues
Click to expand...

With the hassles of everything, if OP goes Enphase sunlight backup, either don't do ESS at all or at least do a small 3.3 kWh battery since like you mention, you still need their smart gateway anyways and having a small battery means you won't be able to backup many loads. Installers won't want to pull your loads due to more work, low $$ as well so you see more inflated quotes.

I've also stated in the past that getting only 1-3 Enphase batteries is probably not worth it neither. 2x 10kWh batteries (6 total 3.3kWh ones) used to run about $25k. Take fed tax credit and if you are lucky to get SGIP, you can see a ~$15k install which is probably close to PW pricing (even though it's still a bit more). I didn't pay much more than 2x Tesla PWs, but of course, the PWs have more kWh.

I'd like to see Matt Ferrell's reasoning for going Enphase. FranklinWH, a newer company has stuff good on paper, but they are new. Specs/features look pretty good though.

Here is his recent video:
 
#22
wwu123 said:
It can, but I believe you also need to install Enphase's equivalent of the Tesla Gateway to manage isolation from the grid, which also makes your system ready for batteries in the future. A friend got quoted about $10K to have that gateway installed, on a solar install that itself was only $10-15K total - that's $10K without any batteries, to get sunlight backup. That installer also said it basically doesn't work, and advised against it - my digging around suggested maybe it's because there's no way to manage loads to ensure they stay below the available solar output, so if your loads are too high, the whole thing probably just shuts down....

I'm interested in the concept, as I have older M215 micro's, that they've supposedly made compatible with this - but not for $10K...
Click to expand...
What price would you accept?
 
#24
cali8484 said:
What price would you accept?
Click to expand...
For my own home scenario, off-grid solar would be worth about $2000 to me, given I only get about 5 hrs/day of usable solar in the winter months when outages are more frequent. But 5 hrs is enough to take a hot shower, run the furnace blower to warm up the house, re-chill the fridge, charge up batteries.

But I know $2K is not going to happen, esp the primary Enphase component is also the one that makes you battery-ready, and it seems generator-ready now (though I checked and it seems they only supports a small number of high-end, large 10-48kw whole home generators).

I was perfectly willing last year, and now, to pay $11.5K to Tesla for one Powerwall and Gateway installed, but it just didn't pencil out to get their required additional solar panels (4-5kw worth), because of my remaining sub-optimal roof orientation/shading. They are about to start selling Powerwalls a la carte for $8K, a Gateway for $1K - though I'm sure no installer will do the job for $2.5K for that either.

So my latest low-tech backup plan is the PG&E Backup Power Transfer Meter for generators, that I started another thread about. I'm trying to verify with PG&E now that I'm eligible for both their $300 generator rebate, as well as the free BPTM installation. If that works, I'll be out-of-pocket only $250 or so for a supported 4000kw generator, and then will start experimenting with using EcoFlow, Bluetti, or one of the other 240V battery "generators" to plug into the BPTM instead....Won't support off-grid solar charging, but will allow whole-home backup battery power without an additional transfer switch.
 
#25
#26
#27
wwu123 said:
But I know $2K is not going to happen, esp the primary Enphase component is also the one that makes you battery-ready, and it seems generator-ready now (though I checked and it seems they only supports a small number of high-end, large 10-48kw whole home generators).
Click to expand...
That's not even close to what Enphase charges just for required support equipment. In any case, only the iQ8 supports sunlight only backup without batteries. So, you would need to upgrade your M215's which adds even more cost.
wwu123 said:
So my latest low-tech backup plan is the PG&E Backup Power Transfer Meter for generators, that I started another thread about. I'm trying to verify with PG&E now that I'm eligible for both their $300 generator rebate, as well as the free BPTM installation. If that works, I'll be out-of-pocket only $250 or so for a supported 4000kw generator, and then will start experimenting with using EcoFlow, Bluetti, or one of the other 240V battery "generators" to plug into the BPTM instead....Won't support off-grid solar charging, but will allow whole-home backup battery power without an additional transfer switch.
Click to expand...

PG&E BPTM based solution may not be as cheap as you think. Unless your solar system is installed via line side tap you will need extra things ($$) done to make sure your solar system is automatically isolated when on generator power.
 
#28
cali8484 said:
That's not even close to what Enphase charges just for required support equipment. In any case, only the iQ8 supports sunlight only backup without batteries. So, you would need to upgrade your M215's which adds even more cost.


PG&E BPTM based solution may not be as cheap as you think. Unless your solar system is installed via line side tap you will need extra things ($$) done to make sure your solar system is automatically isolated when on generator power.
Click to expand...
Yes, as I stated earlier my friend was quoted $10K to add it to a new solar install; $2K was in response to someone asking specifically what it was worth for me. Someone with 13kw system and no winter shading might find more value, but my system is only 4kw and shaded to the east and west in winter. Bummer but moot point that it doesn't work with anything but IQ8; their datasheet and other docs have no clarity about what features of the System Controller (1 or 2) actually are compatible with older micro's, except to say that you can't mix different generations....

Bummer that the BPTM doesn't necessarily work with solar. I thought the first thing they explained it did was to isolate the house from the actual grid at the meter; so I guess you are talking about isolating the solar from the generator and house loads? I assumed the generator wouldn't create anything that would be recognized as a micro-grid by the old micro-inverters, so that they would automatically stop producing, but maybe that was a bad assumption. EDIT: As I think about it, I would have to go manually start the generator after the BPTM does its thing - so at that point I should be able to just flip the breakers for the solar off, that should isolate them I think?
 
#29
wwu123 said:
Yes, as I stated earlier my friend was quoted $10K to add it to a new solar install; $2K was in response to someone asking specifically what it was worth for me. Someone with 13kw system and no winter shading might find more value, but my system is only 4kw and shaded to the east and west in winter. Bummer but moot point that it doesn't work with anything but IQ8; their datasheet and other docs have no clarity about what features of the System Controller (1 or 2) actually are compatible with older micro's, except to say that you can't mix different generations....

Bummer that the BPTM doesn't necessarily work with solar. I thought the first thing they explained it did was to isolate the house from the actual grid at the meter; so I guess you are talking about isolating the solar from the generator and house loads? I assumed the generator wouldn't create anything that would be recognized as a micro-grid by the old micro-inverters, so that they would automatically stop producing, but maybe that was a bad assumption. EDIT: As I think about it, I would have to go manually start the generator after the BPTM does its thing - so at that point I should be able to just flip the breakers for the solar off, that should isolate them I think?
Click to expand...
Yes, if you were to install a generator, you would want to flip off the breakers to the PV system while it is running.
 
#30
wwu123 said:
Yes, as I stated earlier my friend was quoted $10K to add it to a new solar install; $2K was in response to someone asking specifically what it was worth for me. Someone with 13kw system and no winter shading might find more value, but my system is only 4kw and shaded to the east and west in winter. Bummer but moot point that it doesn't work with anything but IQ8; their datasheet and other docs have no clarity about what features of the System Controller (1 or 2) actually are compatible with older micro's, except to say that you can't mix different generations....
Click to expand...
The docs are definitely a bit confusing but only the iQ8 is capable of grid forming.

wwu123 said:
Bummer that the BPTM doesn't necessarily work with solar. I thought the first thing they explained it did was to isolate the house from the actual grid at the meter; so I guess you are talking about isolating the solar from the generator and house loads? I assumed the generator wouldn't create anything that would be recognized as a micro-grid by the old micro-inverters, so that they would automatically stop producing, but maybe that was a bad assumption. EDIT: As I think about it, I would have to go manually start the generator after the BPTM does its thing - so at that point I should be able to just flip the breakers for the solar off, that should isolate them I think?
Click to expand...
That would work but if you ever forget to turn off the PV breaker you could end up damaging your generator.
 
#31
cali8484 said:
Can your Enphase fellow provide documentation?
Seriously doubt it will work with a Ford available today. The only Ford with bidirectional charging is the F150 Lightning and it does not use standards based CCS protocol and Ford has already said it doesn't work with any third-party bidirectional chargers.
Click to expand...


I'm talking to someone on the corporate side. As is usually the case they're more upbeat about what can be delivered than what people in the field can probably deliver. The Enphase Koolaid tastes like grapes.

But yeah they have the wheels are in motion for them to have bidirectional EVSE support... but to your point the OEMs may be locking their partnerships away.

Ford's got Sunrun/Delta
GM has Sunpower
Nissan has Dcbel
Stellantis has some dude with a lifted Ram driving with his high beams on behind you at night
 
#32
wwu123 said:
Yes, as I stated earlier my friend was quoted $10K to add it to a new solar install; $2K was in response to someone asking specifically what it was worth for me. Someone with 13kw system and no winter shading might find more value, but my system is only 4kw and shaded to the east and west in winter. Bummer but moot point that it doesn't work with anything but IQ8; their datasheet and other docs have no clarity about what features of the System Controller (1 or 2) actually are compatible with older micro's, except to say that you can't mix different generations....

Bummer that the BPTM doesn't necessarily work with solar. I thought the first thing they explained it did was to isolate the house from the actual grid at the meter; so I guess you are talking about isolating the solar from the generator and house loads? I assumed the generator wouldn't create anything that would be recognized as a micro-grid by the old micro-inverters, so that they would automatically stop producing, but maybe that was a bad assumption. EDIT: As I think about it, I would have to go manually start the generator after the BPTM does its thing - so at that point I should be able to just flip the breakers for the solar off, that should isolate them I think?
Click to expand...
The issue with the BPTM has been covered elsewhere, but I think that it boils down to needing home wiring such that the PV/Gateway/Powerwall section of the wiring be able to be isolated from the generator feed.

So, I think that the order of events would be
  1. lose power,
  2. isolate PV/Gateway/Powerwall,
  3. start generator with generator main breaker off,
  4. let the generator warm up,
  5. connect generator to BPTM,
  6. throw the generator breaker to on
And, I guess, 7) wait for BPTM to switch to generator power.
 
#33
holeydonut said:
I'm talking to someone on the corporate side. As is usually the case they're more upbeat about what can be delivered than what people in the field can probably deliver. The Enphase Koolaid tastes like grapes.
Click to expand...
Of course, they have to pump up the investors but no worse than Tesla's self-driving taxi fleet that should already have taken over the world by now. Just watch, they will soon announce EnphaseGPT :cool:
 
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#34
BGbreeder said:
The issue with the BPTM has been covered elsewhere, but I think that it boils down to needing home wiring such that the PV/Gateway/Powerwall section of the wiring be able to be isolated from the generator feed.

So, I think that the order of events would be
  1. lose power,
  2. isolate PV/Gateway/Powerwall,
  3. start generator with generator main breaker off,
  4. let the generator warm up,
  5. connect generator to BPTM,
  6. throw the generator breaker to on
And, I guess, 7) wait for BPTM to switch to generator power.
Click to expand...
I finally found the 2022 thread on the PG&E BPTM, but it was hard to find since it didn't preface the word "Backup" nor use the acronym BPTM - though there was no discussion of isolation there. Nonetheless, thanks to you and cali8484 for pointing me in the right direction, I have done more research now on the generator isolation issues. I have further questions but rather than continue to sully this Enphase thread, I'm going to move my follow-up questions over to the thread I started a few days ago:

PG&E EPSS and generator options
 
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#35
For a couple of you here who compare Enphase solar production and Tesla solar production, mine showed withing 1/2 percent in the past with Tesla showing more.
Then, something happened not long ago with no input on my part. I was curious and looked and compared again as in the past periodically.
Now, it is almost exactly the same. Enphase uses 2 decimal places for daily and monthly totals while Tesla is only 1 decimal place. WOW, with that limitation
the difference is in the teen Wh., less than 1/10%.
 
#37
cali8484 said:
The docs are definitely a bit confusing but only the iQ8 is capable of grid forming.


That would work but if you ever forget to turn off the PV breaker you could end up damaging your generator.
Click to expand...
I use a generator interlock similar to this to make sure I don't inadvertantly turn the generator breaker on when the grid is still connected:

Not having something like this to disconnect your solar may not be up to code.
 
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#38
 
#39
cali8484 said:
That's certainly a low cost alternative to the BPTM but it doesn't help with PV isolation.
Click to expand...
Something like this could work if the generator and solar breakers could be placed adjacent to or across from each other (or an additional breaker for the solar). But I don't know if something like this already exists for interlocking two like breakers. You could easily make your own or modify one but it obviously wouldn't be UL approved at that point.
 
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#40
RKCRLR said:
Something like this could work if the generator and solar breakers could be placed adjacent to or across from each other (or an additional breaker for the solar). But I don't know if something like this already exists for interlocking two like breakers. You could easily make your own or modify one but it obviously wouldn't be UL approved at that point.
Click to expand...
If a generator has a breaker in the main panel, then it's not being connected via the BPTM in the first place.

But if there were a scenario where the generator and solar both had breakers in the main panel, would it be possible to had them on opposing sides of a manual transfer switch, feeding into a shared breaker in the main panel? I'm not sure what use case would need something like this though, and then seems like you'd still need another standard generator interlock kit to prevent the main breaker from being on with the generator on. (None of this having any relevance to the BPTM scenario....)

Note to moderator: I tried desperately to move the BPTM discussion over back to my thread that started it, but folks still prefer to discuss it here, ha ha
 
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