New Home, North Carolina, Looking for Options

[NotYetRated]

Building a new certified passive house in Efland North Carolina. I am looking at options for solar+batteries, grid tied system.
Home will be 100% electric. Currently with 1 EV, future state 2 EV's. Estimated yearly utilization will be ~15k kWh with both EV's. Hard to completely iron down with the house not yet built.

Southern Energy Management quoted me an 8kW system+2 Powerwall+ batteries for $50k. Tesla quoted 14kW system+2 Powerwall+ batteries for $49k. I am concerned 1 about those prices, but 2 about future expandability and being locked to Tesla(awful customer service) or Southern Energy(unknown by me) for future expansion needs.

Looking for suggestions from this group on alternative options for:
1. Better pricing options
2. Better equipment options
3. Easier solar AND battery expandability

A system like the following would be ideal, but I am not sure where to find an installer for such a system: https://signaturesolar.com/complete...powerwall-14-000-watts-of-solar-pv-kit-e0005/

 

[FilterGuy]

A system like the following would be ideal, but I am not sure where to find an installer for such a system: https://signaturesolar.com/complete...powerwall-14-000-watts-of-solar-pv-kit-e0005/

Two things:

1) I would consider swapping out the rack batteries for the new EG4 PowerPro wall battery.
2) EG4 has been training a lot of installers. You might want to call them to find a recommendation.

 

[S610]

I am also looking for a residential solar system (off-grid) for a new house. The best (most reliable) brands recommended to me by several here have been Schneider, Victron and Sol-Ark. They always list all three together which means something.

You have to hunt around and find distributors though. Still looking for a Schneider distributor that does residential solar.

 

[S610]

Two things:

1) I would consider swapping out the rack batteries for the new EG4 PowerPro wall battery.
2) EG4 has been training a lot of installers. You might want to call them to find a recommendation.

That EG4 PowerPro looks pretty good especially priced at $4k for 14kW. I got a quote for 3 smaller EG4 batteries totaling 10kW for $5200 so it is definitely a better value for the money.

Would a larger battery last longer with modest night time draining? Seems only using 10-15% on a regular basis would be better than using 20% each of 3 smaller ones.

 

[zanydroid]

If you are draining that little you might run into calendar aging before you ever hit cycle aging. In which case the answer would be that it doesn't matter.

Also such a high average SoC might not be good long term/do not match the deeper cycles actually used during testing/modeling of the cells. And usually cells are stored at lower SoC.

Regarding Victron. Yes they are cool but they obviously don't care that much about North America stationary users (and it is not possible to do several type of code compliant installs, eg rooftop (this is fixable with a non Victron SCC but that loses some of the Victron niceness); not fixable by yourself is the incompatibility with grid tie in most jurisdictions, or ESS). All that is fine in Europe because they actually care there and invest / design products / get listing certificates as necessary.

So why even pay the blue tax for this annoyance.

 

[S610]

If you are draining that little you might run into calendar aging before you ever hit cycle aging. In which case the answer would be that it doesn't matter.

Also such a high average SoC might not be good long term/do not match the deeper cycles actually used during testing/modeling of the cells. And usually cells are stored at lower SoC.

Regarding Victron. Yes they are cool but they obviously don't care that much about North America stationary users (and it is not possible to do several type of code compliant installs, eg rooftop (this is fixable with a non Victron SCC but that loses some of the Victron niceness); not fixable by yourself is the incompatibility with grid tie in most jurisdictions, or ESS). All that is fine in Europe because they actually care there and invest / design products / get listing certificates as necessary.

So why even pay the blue tax for this annoyance.

I thought only using 20% would be better for them. Solar is so incredibly complicated.

And you are right about Victron residential systems. I found one distributor in MS and he normally only does systems for RVs but he said he would send me a quote. The guy that quoted the system brought up concerns about the regulations too.

I have a couple of Sol-Ark quotes and am trying to find a provider to quote Schneider (other than Sig Solar).

 

[FilterGuy]

Would a larger battery last longer with modest night time draining? Seems only using 10-15% on a regular basis would be better than using 20% each of 3 smaller ones.

Lets do some math.

These are rated for 8000 full cycles. If you cycle them 100% every day, it would take 8000/365 = 21 years.....and still have 80% of capacity.

I would not worry about it either way.

 

[S610]

Lets do some math.

These are rated for 8000 full cycles. If you cycle them 100% every day, it would take 8000/365 = 21 years.....and still have 80% of capacity.

I would not worry about it either way.

Thanks! Unless i hear otherwise that battery does look amazingly good!

 

[zanydroid]

I thought only using 20% would be better for them. Solar is so incredibly complicated.

All that said I think you will still hit the promised capacity vs calendar that the specs promise. You might shred them more from the high SoC but less from the reduced cycles.

Also it's not like the batteries will disintegrate at the end of the warranty. If you are only discharging 20% daily for on grid self consumption. that means the batteries could get wrecked down to 30% of original capacity and still be OK for that use case. They wouldn't be that great for off grid multi day backup in cloudy times though.

 

[rhino]

I thought only using 20% would be better for them. Solar is so incredibly complicated.

You are probably thinking about lead acid batteries which is better for them not to be discharged so much. The bigger issue with LiFePO4 batteries regarding degradation is heat. If they were in an unconditioned space and experiencing hot temps frequently there would be a reduction in lifetime cycle count.

 

[S610]

You are probably thinking about lead acid batteries which is better for them not to be discharged so much. The bigger issue with LiFePO4 batteries regarding degradation is heat. If they were in an unconditioned space and experiencing hot temps frequently there would be a reduction in lifetime cycle count.

There had to be a catch! So you are saying they should be in an air conditioned space in the summer? That is problematic, I don't use a/c unless temps reach 100. Plus there is a fire risk with these batteries if they are in the house, isn't there?

 

[zanydroid]

Plus there is a fire risk with these batteries if they are in the house, isn't there?

IRC 2021 code has pretty specific locations where the batteries can go indoors to try to mitigate that. If I had a battery shed where I could exile them that would be my preference if temps don't go below freezing (they cannot be charged while cold). If temps do get that cold then insulation and heaters need to be thought through. Likely for most Lifepo batteries they will have low temperature protection or some heaters built in.

I believe this thread is for NC so you do need to worry about it. But it would be much easier to mitigate than in New England.

 

[S610]

IRC 2021 code has pretty specific locations where the batteries can go indoors to try to mitigate that. If I had a battery shed where I could exile them that would be my preference if temps don't go below freezing (they cannot be charged while cold). If temps do get that cold then insulation and heaters need to be thought through. Likely for most Lifepo batteries they will have low temperature protection or some heaters built in.

I believe this thread is for NC so you do need to worry about it. But it would be much easier to mitigate than in New England.

eG4 PowerPro 14kW brochure claims:

https://eg4electronics.com/wp-content/uploads/2023/08/PowerPro-WallMount-AW-Brochure.pdf

 

[TK1979]

Building a new certified passive house in Efland North Carolina. I am looking at options for solar+batteries, grid tied system.
Home will be 100% electric. Currently with 1 EV, future state 2 EV's. Estimated yearly utilization will be ~15k kWh with both EV's. Hard to completely iron down with the house not yet built.

Southern Energy Management quoted me an 8kW system+2 Powerwall+ batteries for $50k. Tesla quoted 14kW system+2 Powerwall+ batteries for $49k. I am concerned 1 about those prices, but 2 about future expandability and being locked to Tesla(awful customer service) or Southern Energy(unknown by me) for future expansion needs.

Looking for suggestions from this group on alternative options for:
1. Better pricing options
2. Better equipment options
3. Easier solar AND battery expandability

A system like the following would be ideal, but I am not sure where to find an installer for such a system: https://signaturesolar.com/complete...powerwall-14-000-watts-of-solar-pv-kit-e0005/

Have you decided on what to do?

 

[Shawn Hayes]

Building a new certified passive house in Efland North Carolina. I am looking at options for solar+batteries, grid tied system.
Home will be 100% electric. Currently with 1 EV, future state 2 EV's. Estimated yearly utilization will be ~15k kWh with both EV's. Hard to completely iron down with the house not yet built.

Southern Energy Management quoted me an 8kW system+2 Powerwall+ batteries for $50k. Tesla quoted 14kW system+2 Powerwall+ batteries for $49k. I am concerned 1 about those prices, but 2 about future expandability and being locked to Tesla(awful customer service) or Southern Energy(unknown by me) for future expansion needs.

Looking for suggestions from this group on alternative options for:
1. Better pricing options
2. Better equipment options
3. Easier solar AND battery expandability

A system like the following would be ideal, but I am not sure where to find an installer for such a system: https://signaturesolar.com/complete...powerwall-14-000-watts-of-solar-pv-kit-e0005/

You may want to watch YouTube videos by Engineer775. He is located in upstate SC, he may not be local to you, but close enough. He does great installs. He can quote you just as a second estimate to compare?
If you want a cost effective option, have an installer do your panel, inverter and minimal battery install to start for UL certification.
Then later, figure how, what you want to diy and build your own battery system for greater power at a way better price point than off the shelf batteries.
Just for reference, my system:

 

[Browse]

^ This. Engineer775 about 4 hrs to the southwest in Pickens SC. If I lived in that vicinity, he is who I would reach out to, just based on his Youtube videos.