Enphase IQ8 & Powerwall add on

[miimura]

I have an 11 year old Enphase M215 based solar system and recently added a new IQ8 based array. They are totally separate solar systems, but both tied into the Powerwalls in the Generation Panel. The systems are even separate in Enphase Enlighten monitoring. The Tesla CTs just had to go over all the solar wires near the breakers feeding them. You just have to be careful to match the phase and direction of all the wires going through the CTs so they sum correctly.

To the OP, you should definitely figure out why your SolarEdge solar is not working when off-grid. Fixing that is definitely the first step.

 

[wwu123]

I have the Sunlight backup and I was looking at Powerwalls.

I thought if you have IQ8 with Sunlight backup, you basically have the Enphase gateway installed, i.e. the IQ System Controller, to provide grid isolation and micro-grid-forming capability, just without their batteries. Isn't it basically an Enphase battery setup, just without the batteries - shouldn't it be fairly trivial to add Enphase batteries at that point?

Seems much easier than replacing the Enphase gateway with the Tesla Gateway in order to use Powerwalls - since you can't have two different gateways both wanting to do the isolation and grid-forming...

 

[WidowMaker03TX]

I thought if you have IQ8 with Sunlight backup, you basically have the Enphase gateway installed, i.e. the IQ System Controller, to provide grid isolation and micro-grid-forming capability, just without their batteries. Isn't it basically an Enphase battery setup, just without the batteries - shouldn't it be fairly trivial to add Enphase batteries at that point?

Seems much easier than replacing the Enphase gateway with the Tesla Gateway in order to use Powerwalls - since you can't have two different gateways both wanting to do the isolation and grid-forming...

wwu123, I think your right. My desire for Powerwalls may be clouding the obvious answer of Enphase batteries.

 

[CrazyRabbit]

Iq8 inverters need to be used with the enphase disconnect switch to perform grid forming, iq8 inverter grid forming is not compatible with tesla gateway. Iq8 will act like an ordinary inverter with tesla powerwall/gateway and recharge your batteries while off grid.
Your solar needs to be connected to the island side of the gateway and need a solar CT on the solar conductor.

 

[CrazyRabbit]

The IQ8 are able to provide power when the grid is down either by recharging the batteries or powering the house. With my SolarEdge as soon as the grid goes down solar production stops and then I just have to try and stretch out my battery power till grid gets reconnected.

Your solaredge system should be able to recharge your batteries when off grid. Can you explain why your system was not configured in this way?

 

[WidowMaker03TX]

wwu123, I think your right. My desire for Powerwalls may be clouding the obvious answer of Enphase batteries.

Price for 4 Enphase 5P batteries and upgraded components is about $4k more than a 2 PW2 and gateway install.

 

[wwu123]

Price for 4 Enphase 5P batteries and upgraded components is about $4k more than a 2 PW2 and gateway install.

That's disappointing, from looking at some Reddit threads on 5P quotes, sounds like you're basically being quoted the price of a fresh Enphase backup install, and that having an existing IQ System Controller gateway saves nothing. Though that's not too different from folks here trying to add 1 or 2 Powerwalls to an existing Powerwall install and finding quotes same as a fresh install as well. I guess that's how the industry rolls, just like "get as much solar as you can the first time", as there's no cost-effective way to add to an existing solar system. It was also disappointing when I found there was no way even technically to add onto my Enphase M215 microinverter array just 5 years on, because they'd evolved from a 4-wire system to a new 2-wire system that is incompatible...

Funny too, I think an Enphase battery system actually needs less components, not more, than the Enphase Sunlight backup you have now, as you'd no longer need the load-shedding box(es) that I think are required to balance load demand with the latter.

 

[WidowMaker03TX]

That's disappointing, from looking at some Reddit threads on 5P quotes, sounds like you're basically being quoted the price of a fresh Enphase backup install, and that having an existing IQ System Controller gateway saves nothing. Though that's not too different from folks here trying to add 1 or 2 Powerwalls to an existing Powerwall install and finding quotes same as a fresh install as well. I guess that's how the industry rolls, just like "get as much solar as you can the first time", as there's no cost-effective way to add to an existing solar system. It was also disappointing when I found there was no way even technically to add onto my Enphase M215 microinverter array just 5 years on, because they'd evolved from a 4-wire system to a new 2-wire system that is incompatible...

Funny too, I think an Enphase battery system actually needs less components, not more, than the Enphase Sunlight backup you have now, as you'd no longer need the load-shedding box(es) that I think are required to balance load demand with the latter.

wwu123,

Thanks. Its guys like you is why I love this forum. So much knowledge and experience.

 

[lodar]

@Rootcanal1 Any luck investigating your system? Is it setup wrong?

 

[sunwarriors]

Funny too, I think an Enphase battery system actually needs less components, not more, than the Enphase Sunlight backup you have now, as you'd no longer need the load-shedding box(es) that I think are required to balance load demand with the latter.

I'm pretty sure a battery backup needs the same/more equipment (the battery itself is the +1) than only sunlight backup. They both need the main "brains" system controller which can support islanding and has everything going into it (solar/power, batteries, generator, etc). If someone is considering sunlight backup, I always suggest just getting at least a small 3.3 battery since a lot of the hard work is done already once you configure/hook up the main system controller.

Sunlight backup sounds good in concept, but people might as well dump a few more Ks for having the pieces to expand in the future (which is generally a bad idea normally, just build/buy as much as you can on initial install IMO).

 

[wwu123]

I'm pretty sure a battery backup needs the same/more equipment (the battery itself is the +1) than only sunlight backup. They both need the main "brains" system controller which can support islanding and has everything going into it (solar/power, batteries, generator, etc). If someone is considering sunlight backup, I always suggest just getting at least a small 3.3 battery since a lot of the hard work is done already once you configure/hook up the main system controller.

Sunlight backup sounds good in concept, but people might as well dump a few more Ks for having the pieces to expand in the future (which is generally a bad idea normally, just build/buy as much as you can on initial install IMO).

Yes, I was replying to his quote for adding a battery backup to existing Sunlight Backup - obviously needs the added batteries, but "upgraded components" - unless they are replacing the existing system controller with a newer one, probably they would actually be removing the load shedding boxes. So they are basically quoting the labor of a full fresh Enphase battery install, when I think they just need to attach the batteries to the controller and remove/disable components.

My only disagreement with your 2nd statement, is thread after thread here find that none of these systems are cost-effectively expandable in the future - Enphase Sunlight backup, Enphase battery backup, Tesla Powerwall, Tesla solar, non-Tesla solar. Pretty much most vendors quote the cost of a fresh install, regardless of the expansion effort needed. Sunlight backup just happens to be the worst value, in terms of initial cost vs the benefit you get - but is no worse off in terms of no expandability.

 

[WidowMaker03TX]

wwu123, thanks. I'm going with 4 Enphase 5P batteries.

 

[WidowMaker03TX]

Yes, I was replying to his quote for adding a battery backup to existing Sunlight Backup - obviously needs the added batteries, but "upgraded components" - unless they are replacing the existing system controller with a newer one, probably they would actually be removing the load shedding boxes. So they are basically quoting the labor of a full fresh Enphase battery install, when I think they just need to attach the batteries to the controller and remove/disable components.

My only disagreement with your 2nd statement, is thread after thread here find that none of these systems are cost-effectively expandable in the future - Enphase Sunlight backup, Enphase battery backup, Tesla Powerwall, Tesla solar, non-Tesla solar. Pretty much most vendors quote the cost of a fresh install, regardless of the expansion effort needed. Sunlight backup just happens to be the worst value, in terms of initial cost vs the benefit you get - but is no worse off in terms of no expandability.

wwu123,
Thanks again. I finally got the five 5P batteries installed. I'm just waiting for the commissioning.

 

[wwu123]

wwu123,
Thanks again. I finally got the five 5P batteries installed. I'm just waiting for the commissioning.

Congrats! I'm curious if you observed the installation, and whether they indeed just kept in place your existing controller/gateway, and whether any other components/boxes were either added or removed (aside from the 5 batteries of course)...

If mainly just adding the 5P's, hope you got a price break on the installation costs for having the controller already, vs a fresh Enphase install. There's been good news on the Powerwall front as well since the earlier thread discussion in December, as there now seems to be more reasonable add-on pricing for existing Powerwall owners, which have been mentioned in other threads here.