Semi-shaded Hip roof -> 48v DC advice

[BeanFrog]

Hi, I came across this forum and found my people Wealth of knowledge in here. I'm new to solar so bear with me if I'm using the wrong terminology.

The scenario:

• Location: New England (northern lat, high installer labor costs but also high energy prices, and
• my state (MA) has some attractive incentives for having solar storage attached to your PV system
  • They'll pay for kWh pulled from batteries during demand times if you're using a system from
    • Sol-Ark
    • sonnen / outback
    • generac
    • Tesla
    • Solar Edge
    • Enphase
    • or Sunpower
  • more info: https://www.eversource.com/content/...mand-response/battery-storage-demand-response
  • In addition to the demand response payment for stored energy, they'll also pay about 2-5 cents per kWh your system produces for 10 years if you have a battery attached to it (regardless if that kWh was exported, in addition to net metering and a payment of a few pennies just for the PV energy itself (not storage related)). All this amounts to a few hundred $ additional per year if you have storage attached vs without.

Goal:

• minimize the time to cash flow positive (so keep costs down, production and battery storage up)
• secondary goal of maximizing production while minimizing cost per watt (like everyone). Having partial critical loads backup or whole-home backup is really not important, though would be a nice to have

The challenge

• it's a hip roof (like a pyramid, w. different faces getting sun throughout the day/year and differing shading patterns throughout the day). All the designs I've see have panels on at least 3 roof faces at different angles to the sun. See attached for an image example
• So a microinverter like IQ or APsystems could make sense here,
• AC systems like Enphase -> AC battery pairing quotes are too high (the quotes I'm getting for 10kWh batteries installed are $13-15K which makes this cost prohibitive

My question: what's the best inverter / PV > battery system that can handle some different roof angles and shading, but also supports cheap bring-your-own batteries, (or at least not $1,000 per kWh prices)?

Should I be thinking of tigo optimizers with a Sol-Ark 12K, and a battery from signature solar or bigbattery.com? Any other solutions people would recommend that gets me cheap[er] storage than these Enphase uncharge 10 quotes I've been getting?

 

[MisterSandals]

You seem to have a very good grasp of the issues. Maybe peruse the Sho and Tell area as these are mostly success stories.

Show and Tell

Post your DIY solar power system! Pictures or it didn't happen :)

diysolarforum.com

And welcome!

 

[BeanFrog]

You seem to have a very good grasp of the issues. Maybe peruse the Sho and Tell area as these are mostly success stories.

Show and Tell

Post your DIY solar power system! Pictures or it didn't happen :)

diysolarforum.com

And welcome!

Thanks MisterSandals! Wasn't aware of that section, I'll peruse the success stories.

 

[onokai]

I would sugest the Sol-arc and tigo optimizers-I have that setup-I'm new to this forum -I have explained my system in the newbie section. I also have the kilovolt 7.5 kw litithum batteries (2 of them). I got most of it from Alt-e web store -they are close to you (outside Boston)One other note about alt-e they run a sale in springtime as well

 

[BeanFrog]

I would sugest the Sol-arc and tigo optimizers-I have that setup-I'm new to this forum -I have explained my system in the newbie section. I also have the kilovolt 7.5 kw litithum batteries (2 of them). I got most of it from Alt-e web store -they are close to you (outside Boston)One other note about alt-e they run a sale in springtime as well

super helpful info, I couldn't get Sol-Ark to confirm if the Tigo's were recommended with the Sol-Ark, but had no reason to suspect they wouldn't. Thanks for confirming that. Have you experienced any of the issues with heavy 120v inductive loads that I've seen mentioned elsewhere? Ben's Solar an Battery mentioned in his YouTube channel he had to install a SolarEdge AutoTransformer to even out the two 240v lines when using heavy L-N 120v loads . Apparently the Sol-Ark didn't like them being imbalanced and would shutdown without that autotransformer. If my solar system can't handle a hairdryer and toaster then I'll be in the doghouse

those batteries are pretty burly, 120-150 amp charge and discharge rate!? Might need to get two of em and a sol-ark 15 and be set for a while

 

[onokai]

super helpful info, I couldn't get Sol-Ark to confirm if the Tigo's were recommended with the Sol-Ark, but had no reason to suspect they wouldn't. Thanks for confirming that. Have you experienced any of the issues with heavy 120v inductive loads that I've seen mentioned elsewhere? Ben's Solar an Battery mentioned in his YouTube channel he had to install a SolarEdge AutoTransformer to even out the two 240v lines when using heavy L-N 120v loads . Apparently the Sol-Ark didn't like them being imbalanced and would shutdown without that autotransformer. If my solar system can't handle a hairdryer and toaster then I'll be in the doghouse

those batteries are pretty burly, 120-150 amp charge and discharge rate!? Might need to get two of em and a sol-ark 15 and be set for a while

I love the sol-arc and their service tecs on the phone. I have fired a 48 amp kiln for 8 hours on a sunny day in the prime hours a few times-thats about as much as one can draw on my 9,600 watt panel system. The sol arc did it without any error codes . Hairdryers and coffee makers - are piece of cake. We are on a well and that 3/4 hp motor draws a lot. Our daily average is 17-19 kw which is high. I opewrate a full on potter studio here for past 49 years.With the clay mixing machines and deep water well I can suck up a few watts. You can wire the loads more evenly on your buss bars. Spread them out side to side with the breakers. Standard electrical practice. No trouble for me with uneven loads and Sol arc. My location is 40 ish latitude in Nor -cal North of Eureka nedar the coast. The two 7.5 batteries carry us thru the night just fine also thru the high dollar 5pm to 8 pm local utility high rate hours .We switch to batteries at 5 pm year around.

 

[Shinebox]

Hi, I came across this forum and found my people Wealth of knowledge in here. I'm new to solar so bear with me if I'm using the wrong terminology.

The scenario:

• Location: New England (northern lat, high installer labor costs but also high energy prices, and
• my state (MA) has some attractive incentives for having solar storage attached to your PV system
  • They'll pay for kWh pulled from batteries during demand times if you're using a system from
    • Sol-Ark
    • sonnen / outback
    • generac
    • Tesla
    • Solar Edge
    • Enphase
    • or Sunpower
  • more info: https://www.eversource.com/content/...mand-response/battery-storage-demand-response
  • In addition to the demand response payment for stored energy, they'll also pay about 2-5 cents per kWh your system produces for 10 years if you have a battery attached to it (regardless if that kWh was exported, in addition to net metering and a payment of a few pennies just for the PV energy itself (not storage related)). All this amounts to a few hundred $ additional per year if you have storage attached vs without.

Goal:

• minimize the time to cash flow positive (so keep costs down, production and battery storage up)
• secondary goal of maximizing production while minimizing cost per watt (like everyone). Having partial critical loads backup or whole-home backup is really not important, though would be a nice to have

The challenge

• it's a hip roof (like a pyramid, w. different faces getting sun throughout the day/year and differing shading patterns throughout the day). All the designs I've see have panels on at least 3 roof faces at different angles to the sun. See attached for an image example
• So a microinverter like IQ or APsystems could make sense here,
• AC systems like Enphase -> AC battery pairing quotes are too high (the quotes I'm getting for 10kWh batteries installed are $13-15K which makes this cost prohibitive

My question: what's the best inverter / PV > battery system that can handle some different roof angles and shading, but also supports cheap bring-your-own batteries, (or at least not $1,000 per kWh prices)?

Should I be thinking of tigo optimizers with a Sol-Ark 12K, and a battery from signature solar or bigbattery.com? Any other solutions people would recommend that gets me cheap[er] storage than these Enphase uncharge 10 quotes I've been getting?

The connected solutions program that you’re referring to doesn’t come right out and say it, but what they’re looking for with your battery is that is is UL 9450 listed. Not that many batteries are. I don’t think signature solar, Gyll etc server rack batteries are. Sol Ark has a preferred list of vendors that are 48v and meet this listing. None are cheap. It’s a bit clumsy of them to list the requirements this way, but when you get the permits for all of this, an engineer will be signing off on the install. Another thing to be aware of is that while Sol Ark is listed as an approved inverter for this system, if you look at the actual application, there is a box to check for all the inverters that you listed except the Sol Ark. I know this because I was interested in using a Sol Ark with a diy battery only to discover all that I have mentioned. I called Sol Ark and asked about this and they said that they had done all of the leg work to be certified, but wished me luck in getting someone on the phone at MassSaves to sort out getting connected with a Sol Ark

 

[BeanFrog]

The connected solutions program that you’re referring to doesn’t come right out and say it, but what they’re looking for with your battery is that is is UL 9450 listed. Not that many batteries are. I don’t think signature solar, Gyll etc server rack batteries are. Sol Ark has a preferred list of vendors that are 48v and meet this listing. None are cheap. It’s a bit clumsy of them to list the requirements this way, but when you get the permits for all of this, an engineer will be signing off on the install. Another thing to be aware of is that while Sol Ark is listed as an approved inverter for this system, if you look at the actual application, there is a box to check for all the inverters that you listed except the Sol Ark. I know this because I was interested in using a Sol Ark with a diy battery only to discover all that I have mentioned. I called Sol Ark and asked about this and they said that they had done all of the leg work to be certified, but wished me luck in getting someone on the phone at MassSaves to sort out getting connected with a Sol Ark

amazing timing Shinebox, I was this close to hitting buy on the system.

I checked out that page, https://www.eversource.com/content/...tery-storage-demand-response/application-form - Sol-Ark is listed under battery but not under inverter. Very strange. I emailed connected solutions to clarify if it is indeed supported. Unless you want to submit the form with Sol-Ark selected as battery and report back?

As a workaround I saw Sol-Ark has their own submission form, where you can upload your system design etc and they'll seemingly submit it on your behalf maybe? https://www.sol-ark.com/vppconnectedsolutions/ Not sure how they do that without your utility account number

 

[onokai]

If you are buying a Sol Arc they have a battery list of ones that work with a BSM connection (I hope I got the intails right) connection. My Kilovolts did not have this when I bought them over a year ago but they where working on it.Their technical worked me thru that install. No big deal.I would stick to batteries Sol-Arc talks to for best results.

 

[Shinebox]

amazing timing Shinebox, I was this close to hitting buy on the system.

I checked out that page, https://www.eversource.com/content/...tery-storage-demand-response/application-form - Sol-Ark is listed under battery but not under inverter. Very strange. I emailed connected solutions to clarify if it is indeed supported. Unless you want to submit the form with Sol-Ark selected as battery and report back?

As a workaround I saw Sol-Ark has their own submission form, where you can upload your system design etc and they'll seemingly submit it on your behalf maybe? https://www.sol-ark.com/vppconnectedsolutions/ Not sure how they do that without your utility account number

Interesting. I have national grid, and last I checked, Sol Ark isn’t even listed. I’m sure it can be worked out, but it’s a pain. It’s also not great that people using Sol Arks could potentially buy batteries that won’t get approved when they inspect the system. All of the other inverters listed are HV and either work with a single proprietary battery, like enphase or Tesla, or they are HV and the choices for HV are limited like LG Resu or Sonnen.

 

[BeanFrog]

Confirmed with Eversource the website missing Sol-Ark was a mistake they'll be correcting and the sol-ark is definitely eligible. Confirming now whether UL 1973 or UL 4850 would be a requirement, and if it needs to 'speak' to the Sol-Ark or simply be connected. I'll report back what I hear.

To onokai's point on the battery UL cert/listings, I found this thread https://diysolarforum.com/threads/ul-batteries.35247/ that pointed me to this sheet https://docs.google.com/spreadsheets/d/1vkRfsckYZs0M5bKzcd395HA2cmzJrUs9DSDYGuabSiY/edit?usp=sharing tracking some of the 48v battery options. Seems SimpliPhi and Fortress are probably your best bets, albeit at like $600-700/kWh which is double the price of the signature solar ones :-/

This UL listing question is getting me less convinced this will pay off the way I was hoping. I really was hoping putting a Sol-Ark in and connect a cheaper LiFePo4 battery so I could get whole-home backup to pay for itself in ~4 years, but if I'll have to spend $10-15k ish on a UL listed battery, the payoff won't make this worth it. I'd be better off just getting a standard solar install with microinverters and skipping storage. Stupid they're trying to incentivize PV energy storage but then making it not financially feasible.

 

[Shinebox]

Confirmed with Eversource the website missing Sol-Ark was a mistake they'll be correcting and the sol-ark is definitely eligible. Confirming now whether UL 1973 or UL 4850 would be a requirement, and if it needs to 'speak' to the Sol-Ark or simply be connected. I'll report back what I hear.

To onokai's point on the battery UL cert/listings, I found this thread https://diysolarforum.com/threads/ul-batteries.35247/ that pointed me to this sheet https://docs.google.com/spreadsheets/d/1vkRfsckYZs0M5bKzcd395HA2cmzJrUs9DSDYGuabSiY/edit?usp=sharing tracking some of the 48v battery options. Seems SimpliPhi and Fortress are probably your best bets, albeit at like $600-700/kWh which is double the price of the signature solar ones :-/

This UL listing question is getting me less convinced this will pay off the way I was hoping. I really was hoping putting a Sol-Ark in and connect a cheaper LiFePo4 battery so I could get whole-home backup to pay for itself in ~4 years, but if I'll have to spend $10-15k ish on a UL listed battery, the payoff won't make this worth it. I'd be better off just getting a standard solar install with microinverters and skipping storage. Stupid they're trying to incentivize PV energy storage but then making it not financially feasible.

This is the conclusion I quickly reached.

 

[onokai]

My Kilovaults batteries are just connected to the Sol-arc -not yet talking to them. I was waiting for Sol arc to work thru this with Kilovault which they are doing last time i checked

 

[onokai]

This is the conclusion I quickly reached.

That list is incomplete as well-The Kilo Vaults are UL cert and not on that list-https://www.altestore.com/store/deep-cycle-batteries/lithium-batteries/kilovault-hab-75kwh-150ah-48v-lithium-battery-p41596/?gclid=Cj0KCQjwxtSSBhDYARIsAEn0thTTJPucuR81xYuWh1YfFUxmVURVJCRun3Cy9M3XLrdlnEuImCB50RkaAumMEALw_wcB#KLVHAB7_5V3

 

[BeanFrog]

That list is incomplete as well-The Kilo Vaults are UL cert and not on that list-https://www.altestore.com/store/deep-cycle-batteries/lithium-batteries/kilovault-hab-75kwh-150ah-48v-lithium-battery-p41596/?gclid=Cj0KCQjwxtSSBhDYARIsAEn0thTTJPucuR81xYuWh1YfFUxmVURVJCRun3Cy9M3XLrdlnEuImCB50RkaAumMEALw_wcB#KLVHAB7_5V3

saw that, but the KiloVault is only UL1973 listed, not UL9540. UL9540 is a new (as of 2016) standard that applies just to Energy Storage Systems: https://www.ul.com/news/ul-9540-ene...s-evolving-meet-industry-and-regulatory-needs . Not to be confused with UL9540A which is fire spreading certification. YMMV in the sense that it 100% depends on your local building code enforcer and what requirements they have. I knew there was some reason all solar installers are pushing just 3 different batteries...

 

[Shinebox]

saw that, but the KiloVault is only UL1973 listed, not UL9540. UL9540 is a new (as of 2016) standard that applies just to Energy Storage Systems: https://www.ul.com/news/ul-9540-ene...s-evolving-meet-industry-and-regulatory-needs . Not to be confused with UL9540A which is fire spreading certification. YMMV in the sense that it 100% depends on your local building code enforcer and what requirements they have. I knew there was some reason all solar installers are pushing just 3 different batteries...

That’s the key point. In MA with this program it really comes down to whoever inspects and signs off on your system. A friend of mine who owns a solar design and install company has told me about some instances where systems using even HV components (ie those that are more or less prescriptively detailed by the program documents) have been held up for months because of a sole inspector or engineer from the utility not willing to sign off. On the flip side you could have someone sign off on a frankenbattery, though not likely.