Leaning into solar from Texas

[BudT]

Just a quick intro to say hello. I have been interested in solar for several years. Back in 2017 I was pretty hot and heavy on it when we experienced a natural disaster in our area named Hurricane Harvey that dumped about 50" of rain over a few days. Our home which is in Zone X (not a flood zone) flooded causing me to put the solar program on hold. 2 years later, we had about 50" of rain in about 12 hours, Tropical Storm Imelda, hard to imagine, I know but it happened again. BTW, the first event was called a 1000 yr flood, funny right? 2 years later it happened again (that was a very fast 1k years). Anyhow I think I'm at a point where I'm ready to move forward with the solar program, it's time to pull the trigger.

Right now, I'm looking at about a 25kw ground array on a Ready Rack helical mount, still looking at and researching panels. I came across "Projects with everyday Dave" videos and like what he did, so I'll probably try to mirror his project. I have seen the Sol-Ark 15k and I like what I see. I'm not a real techno nerd, I like things that work plug and play, just want it to work. Our home has a 400 amp (320cl meter) feed that then goes to 2 - 200 amp breaker boxes, so from what I can tell, looks like I may have to go with 2 of the Sol Arks (still researching). We have net metering, but the buyback is about 0.5 to 1 through Entergy Texas, better than nothing I suppose. But because of this, I am going to plan to do battery install as well.

I'm in the oil and gas industry, a few years from retirement, have an AAS in Instrumentation and Electronics, and I'm pretty handy from pool equipment, to home construction, with a little automotive mixed in. I pretty much would rather do it myself than pay someone to do a half ass job. Thats not in all cases, there are still some true craftspeople out there, just not as many to go around, especially in a rural area like where we are. I really dont know a lot about anything, but know a little about most things, and in todays world, just about any subject is only a few keystrokes away. If the project comes to life I'll keep y'all up to date. I really like what I see here on the site, great work, and a seemingly great community of like minded people sharing info. Thanks to those that make it happen.

Peace from Texas,
BudT

 

[12VoltInstalls]

Our home has a 400 amp (320cl meter) feed that then goes to 2 - 200 amp breaker boxes

Holy cow!
That’s a lot of demand for residential.

 

[Bluedog225]

Welome Bud!

There’s a lot to learn but it’s do-able. If you run your system by this group before you start buying it will save you some time and money. Also, research your vendors here. There are some good, some not so great.

Rumor is that batter prices may be on the way down. Maybe way down. I’d buy those last. And look at all the options from diy and rack to the bigger prepackaged deals that you put on a slab.

And give some thought to whether the brand you choose will be around long term in light of all the cheaper all in one competition. I’m thinking sol ark versus Victron. And there may be some issues with sol ark and storing data overseas. I have not followed closely.

Good luck.

 

[1201]

Diy will take a lot of time and research but will save you tons of money. Welcome.

If you are going with a solark it's going to be easier to write than individual components so you're already off to a good start. There are huge savings to be had with diy batteries. About $4500-5k for 28kwh instead of $8600-1000 with off the shelf batteries. They are very easy to do so don't be intimidated.

 

[OzSolar]

I'm not a real techno nerd, I like things that work plug and play, just want it to work. Our home has a 400 amp (320cl meter) feed that then goes to 2 - 200 amp breaker boxes, so from what I can tell, looks like I may have to go with 2 of the Sol Arks (still researching)

Welcome! You'll do yourself a favor by getting something like the Emporia Vue to see where, when and how you are using power. I bet you're rarely, if ever, close to needing all of of that 400 amp service. In the long run it may better to move some loads around and back up just one of your 200 amp panels.

Hard to beat the Sol-Ark with that 200 amp pass through capability and built in solar MPPT's.

 

[Philip53]

Hello Bud, and welcome to the forum! There is so much info & good advice here, and with your background, you should not have any problem installing your own system. I installed mine 12 years ago, and without the wealth of info that is presented here.

As far as your desire to plug & play without a bunch of issues, please look at the tier one equipment that is out there, such as Schneider, Outback, Victron, and a few others. I would definitely go with a low frequency transformer inverter. They cost more, but have many advantages. Personally, I have the original Schneider 6048 inverter with 3 of their SCC's. Never a problem with any of the components after 12 years, and never a shutdown issue. In fact, I have only manually shut it down once - last year when I added a 3rd array. The added cost of the best & most reliable equipment will be quickly forgotten, and much better than the likely issues you may otherwise have during the next decade plus of ownership.

Good luck to you!

 

[BudT]

Holy cow!
That’s a lot of demand for residential.

You are right, it is a lot for residential. The first home we bought we completely rebuilt the service, and added a new garage and another 1k sq' of living area. The electrical was always the achilles heel, so when we built the home we are in now I knew we would eventually have a pool and detached climate controlled garage ect., so I went with my BIL's (IBEW Electrician) advice on the liberal design of the electrical service. Do we use it all or, are we out of room? Not even close. But, what I don't have is the problems I had before, which was being on the edge of total capacity. As with everything in life, this is another one of those trade offs. Sometimes when we think we are making a no-brainer type of decision, it is only because we can't see around the curve. When we built this home in 2008, solar or alternative energy never entered my mind. We'll find a way around this also. Thanks for your comment.

 

[BudT]

Thanks to all of you who commented and welcomed me here. Like I said in the intro, it's been a little while since I seriously entertained this endeavor, but more likely now than ever, it just makes good sense. I do appreciate the suggestions some of you made to consider and research different options. As with anything I have ever done, I thought I had done a really good job of researching and learning about what I was getting into, only to find out, once I was neck deep, that was when the real education and becoming proficient on the subject matter really occurred. I'm gonna do my best to get this as close to right as I can, and leaning on some of you will help me tremendously. The plan will be to pay that forward to others who will have an interest based on the success that I hope we experience. One of the concerns I have is to be able to set this system up in such a way that if something happens to me, my wife will be able to have the confidence she needs to be able to manage and have this system serviced in my absence. If I can't do this, then it may not be right for us at this time. What I can see is the advances that have been made in the time I looked into it in 2016 vs today. Thanks again to those that make this resource available to the rest of us, and to those who genuinely try to assist others.

 

[Hedges]

Load management to keep powering critical loads and important loads as battery SoC gets low. Dump load to utilize excess PV production when batteries are full. Load dump to shed nice but excessive loads like whole-house A/C when PV can't keep up.

PV hardware makes power for $0.025/kWh (amortized over 20 years) if you can use all of it. LiFePO4 batteries cost $0.05/kWh if they last claimed number of cycles. Some big name batteries cost much more.

Given such prices, I think 0.5 to 1 buyback by utility is a better deal than batteries. Just install 2x PV.

I favor excess PV, and arrays aimed SE and SW to make power longer. Reduces the amount of limited life battery required. Of course generator is useful off-grid, but if grid is available, far cheaper and easier.

SolArk, you can stack more for more kW inverter. 200A passthrough is good for your breaker boxes, but of course inverter couldn't keep up with same load. SolArk can also do 3-phase.

I use SMA, Sunny Island is a premium quality product, available liquidation prices on eBay. Stacks to 24kW split-phase or 18kW 3-phase, plus more from AC coupling when sun shines. But not much more pass-through from grid; external 200A relay only supported by European model.

Newer brands and models offer support for shifting time of import and export, take advantage of or avoid getting burned by time of use rates.

Look at Midnight Rosie and B17. From some of the most respected and earliest people in the business. Their new products are HF (like SolArk, unlike Sunny Island and Schneider), but have 3x surge.

 

[Dave911]

Load management to keep powering critical loads and important loads as battery SoC gets low. Dump load to utilize excess PV production when batteries are full. Load dump to shed nice but excessive loads like whole-house A/C when PV can't keep up.

PV hardware makes power for $0.025/kWh (amortized over 20 years) if you can use all of it. LiFePO4 batteries cost $0.05/kWh if they last claimed number of cycles. Some big name batteries cost much more.

Given such prices, I think 0.5 to 1 buyback by utility is a better deal than batteries. Just install 2x PV.

I favor excess PV, and arrays aimed SE and SW to make power longer. Reduces the amount of limited life battery required. Of course generator is useful off-grid, but if grid is available, far cheaper and easier.

SolArk, you can stack more for more kW inverter. 200A passthrough is good for your breaker boxes, but of course inverter couldn't keep up with same load. SolArk can also do 3-phase.

I use SMA, Sunny Island is a premium quality product, available liquidation prices on eBay. Stacks to 24kW split-phase or 18kW 3-phase, plus more from AC coupling when sun shines. But not much more pass-through from grid; external 200A relay only supported by European model.

Newer brands and models offer support for shifting time of import and export, take advantage of or avoid getting burned by time of use rates.

Look at Midnight Rosie and B17. From some of the most respected and earliest people in the business. Their new products are HF (like SolArk, unlike Sunny Island and Schneider), but have 3x surge.

How do you get started understanding the Sunny Island units? There doesnt seem to be a lot of info floating around about them. Whats too old, etc. They have been around for a long time.

 

[1201]

How do you get started understanding the Sunny Island units? There doesnt seem to be a lot of info floating around about them. Whats too old, etc. They have been around for a long time.

What are you trying to do?

 

[Hedges]

RTFM
I read the manuals for Sunny Island cover to cover.

Nothing is too old about them (at least the 5048US, and 4548 & 6048US; there are earlier models), and they work great at least with similarly old Sunny Boys. Should also work great with newer models set to "Island mode 60" or similar.
I'm not sure if there are issues with "Rule 21" of SB -40 & -41 to support both on and off grid. I suspect so because SMA America in a video recommended the off-grid "Island" setting instead.

What they don't have is peak shaving or time shifting functions. Maybe that could be imposed with an external controller that has CT on grid connection and a real time clock.

I think SI + SB can make a great off-grid system, or can use grid as generator. It can also provide back during grid failures for an existing GT PV system. As mentioned, not sure if there are issues with newer Rule-21 inverters. It is UL listed but not on current CEC list. Can't be used as a PV inverter (e.g. with DC coupled SCC). I think it should be allowed as UPS or backup system, except or new rules about ESS especially for lithium. Not sure if those would prevent permitting or if OK with UL Recognized AGM.

For peak shaving and time shifting, some other brand/model will be needed.

 

[Dave911]

RTFM
I read the manuals for Sunny Island cover to cover.

Nothing is too old about them (at least the 5048US, and 4548 & 6048US; there are earlier models), and they work great at least with similarly old Sunny Boys. Should also work great with newer models set to "Island mode 60" or similar.
I'm not sure if there are issues with "Rule 21" of SB -40 & -41 to support both on and off grid. I suspect so because SMA America in a video recommended the off-grid "Island" setting instead.

What they don't have is peak shaving or time shifting functions. Maybe that could be imposed with an external controller that has CT on grid connection and a real time clock.

I think SI + SB can make a great off-grid system, or can use grid as generator. It can also provide back during grid failures for an existing GT PV system. As mentioned, not sure if there are issues with newer Rule-21 inverters. It is UL listed but not on current CEC list. Can't be used as a PV inverter (e.g. with DC coupled SCC). I think it should be allowed as UPS or backup system, except or new rules about ESS especially for lithium. Not sure if those would prevent permitting or if OK with UL Recognized AGM.

For peak shaving and time shifting, some other brand/model will be needed.

RTFM...thats fair, but Im not interested in reading ALL the SMA manuals. Im confused by the Sunny Island vs Sunny Boy units. I thought the SBs were grid tie only? But then I read thats not necessarily true? Can I assume Sunny Islands were designed for off grid use only? Should units other than the xx48US models not be considered? There are a lot of old Sunny Boy units floating around. A lot of these have to be technically obsolete? Or not?
Im not interested in feeding power back into the grid. So off grid it is. Not trying to load shift.
I care about UL but don't care about current CA regs.

 

[Hedges]

I meant read the Sunny Island manual(s).

SMA invented the grid-tie PV inverter and introduces the Sunny Boy.
SMA invented the battery inverter which AC couples to grid-tie PV inverter and introduces the Sunny Island.

Sunny Island has AC1 connection for loads it feeds and AC2 connection for grid or battery. It can pass through grid to loads and blend power inverted from battery, for instance limiting current from grid to 15A while adding 35A for 50A to load.
If battery is charged higher than SI wants, it can backfeed the grid just like a grid-tie inverter. It is only UL-1741, not -SA or -SB, so doesn't meet most recent rules for backfeeding.

You can build a system with 2x SB 6048US that will put out 11.5kW continuous from battery, can have up to 13.4kW of SB attached and backfeed the grid. Or up to 24kW of SB attached if never backfeeding the grid, just operating offgrid (with optional generator or grid input, no backfeed.)

SI 4548US, 5048US, 6048US are firmware compatible and can operate together in a split-phase or 3-phase cluster. But on a single 120V phase, only one model can be used. I have 4x SI 6048 wired 2p2s for split-phase able to pass through 100A from grid. The 4548US specs show output rapidly derated with temperature. The others maintain much higher output.

There is an earlier 4248US which I think may use something other than frequency shift power control, may also not be stackable. I've never worked with it. An earlier 4500 and some other models are European voltages only.

As for Sunny Boys, old and new ones should all be good. A few don't work with Sunny Island, so check the list before buying.

https://files.sma.de/downloads/SB-OffGrid-TI-US-en-23.pdf

The models up through SB 5000US series were either negative ground or configurable positive/negative ground. That should prevent "PID" in PV panels. The later models are transformerless; for those make sure PV panels are "PID free"

The recently discontinued SB -40 an -41 should meet current codes for connecting to grid (only -41 supports RSD). But all are UL listed.
Any on the compatibility list should make a very robust off-grid system. Add a load-shed relay to cut all most most critical loads and keep SB powered waiting for sun to come up (don't want dead battery and black-start issue.)

Batteries. SI supports FLA and VRLA with configurable parameters. Some people set those parameters and connect a lithium battery without communications. Otherwise, with firmware updated as required, SI can talk to some brands of BMS. REC is popular (but expensive) for DIY. There are batteries from BYD and others which are supported. We've recently heard that EG4 PowerPro works.

I try to buy Sunny Boys around $0.10/W. I got my most recent Sunny Islands for $0.25/W (first one cost me $1/W), but prices today are around $0.33/W +/-.

 

[shadowmaker]

Hmm. Is there a reason to call Solark tier 2/3 product? I mean there's a thread of their failure rate (https://diysolarforum.com/threads/have-you-had-a-sol-ark-failure.65795/) and it shows no problems.

I understand it is cheap China shit (Deye) until they label it Sol-Ark and then it is expensive China shit, but what's the reason not being tier 1? I have two Deye 12Ks (~Solark 15K) working nicely for a year (2300e/pc = 2500$/pc), but there are people using multiple years these products now and failure rate seems very low. Who decides which product is tier 1 or not?

 

[Dave911]

I meant read the Sunny Island manual(s).

SMA invented the grid-tie PV inverter and introduces the Sunny Boy.
SMA invented the battery inverter which AC couples to grid-tie PV inverter and introduces the Sunny Island.

Sunny Island has AC1 connection for loads it feeds and AC2 connection for grid or battery. It can pass through grid to loads and blend power inverted from battery, for instance limiting current from grid to 15A while adding 35A for 50A to load.
If battery is charged higher than SI wants, it can backfeed the grid just like a grid-tie inverter. It is only UL-1741, not -SA or -SB, so doesn't meet most recent rules for backfeeding.

You can build a system with 2x SB 6048US that will put out 11.5kW continuous from battery, can have up to 13.4kW of SB attached and backfeed the grid. Or up to 24kW of SB attached if never backfeeding the grid, just operating offgrid (with optional generator or grid input, no backfeed.)

SI 4548US, 5048US, 6048US are firmware compatible and can operate together in a split-phase or 3-phase cluster. But on a single 120V phase, only one model can be used. I have 4x SI 6048 wired 2p2s for split-phase able to pass through 100A from grid. The 4548US specs show output rapidly derated with temperature. The others maintain much higher output.

There is an earlier 4248US which I think may use something other than frequency shift power control, may also not be stackable. I've never worked with it. An earlier 4500 and some other models are European voltages only.

As for Sunny Boys, old and new ones should all be good. A few don't work with Sunny Island, so check the list before buying.

https://files.sma.de/downloads/SB-OffGrid-TI-US-en-23.pdf

The models up through SB 5000US series were either negative ground or configurable positive/negative ground. That should prevent "PID" in PV panels. The later models are transformerless; for those make sure PV panels are "PID free"

The recently discontinued SB -40 an -41 should meet current codes for connecting to grid (only -41 supports RSD). But all are UL listed.
Any on the compatibility list should make a very robust off-grid system. Add a load-shed relay to cut all most most critical loads and keep SB powered waiting for sun to come up (don't want dead battery and black-start issue.)

Batteries. SI supports FLA and VRLA with configurable parameters. Some people set those parameters and connect a lithium battery without communications. Otherwise, with firmware updated as required, SI can talk to some brands of BMS. REC is popular (but expensive) for DIY. There are batteries from BYD and others which are supported. We've recently heard that EG4 PowerPro works.

I try to buy Sunny Boys around $0.10/W. I got my most recent Sunny Islands for $0.25/W (first one cost me $1/W), but prices today are around $0.33/W +/-.

Thanks Hedges,
This helps a lot.
How difficult is it to get these devices reflashed with newer firmware if required?
Apparently codes are required to change modes sometimes?
Are the codes in the manuals or are they unique to the devices via serial numbers, so the mode change codes must come from SMA?
Compared to new Chinese inverters these seem to sell at a premium on the used market.
An SRNE 10K hybrid goes for about $1500.
A used SI and SB combo would be more than twice the price? Still worth it?
I dont read of many issues with Sunny Islands or Sunny Boys.

 

[Bluedog225]

Victron-“When it Absolutely, Positively Has to” just work.

 

[Danke]

Hmm. Is there a reason to call Solark tier 2/3 product? I mean there's a thread of their failure rate (https://diysolarforum.com/threads/have-you-had-a-sol-ark-failure.65795/) and it shows no problems.

I understand it is cheap China shit (Deye) until they label it Sol-Ark and then it is expensive China shit, but what's the reason not being tier 1? I have two Deye 12Ks (~Solark 15K) working nicely for a year (2300e/pc = 2500$/pc), but there are people using multiple years these products now and failure rate seems very low. Who decides which product is tier 1 or not?

It will be a while before I install my 12Ks. I’m hoping to have a similar experience as you with them.

 

[Hedges]

How difficult is it to get these devices reflashed with newer firmware if required?

If you have the ability to write an SD card (full size, think it is 2 GB max and FAT32) should be pretty easy, using front panel pushbuttons.
I haven't updated them, have followed step by step to save state to a card and upload for SMA support.

Otherwise, there are RS-485 communication methods. You buy and install a daughter card (same one used when telling older SB 5000US to switch between UL-1741 and offgrid parameters, not needed when always offgrid except one time to set SB parameters). Connect a communication device (discontinued WebBox), and I think that can transfer.

(I did update one TriPower through Sunny Explorer software and Ethernet.)

It looks like the SI 6048US being liquidated due to DC Solar bankruptcy already support an external BMS. Some 5048US from earlier times don't.

Apparently codes are required to change modes sometimes?
Are the codes in the manuals or are they unique to the devices via serial numbers, so the mode change codes must come from SMA?

Some parameters require installer to enter a "password" which is simply sum of digits of the operating hours it displays.
Some parameters related to UL-1741 require "grid guard code", which you request from SMA and they give if they consider you a "qualified individual". One forum member got that by providing a document from PG&E saying the parameters had to change from UL-1741 to Rule-21.

Sunny Boy similarly require Grid Guard, including to change an old one from UL-1741 to offgrid. One grid guard code works for all SMA equipment, and is a fingerprint showing you're the one who altered settings.

For inverters locked with user & installer passwords you don't know, SMA will provide Personal Unlocking Code, which is actually a code unique to serial number.

You're likely to need Grid Guard and PUK if you buy used Sunny Boys, and want to configure for offgrid.

Compared to new Chinese inverters these seem to sell at a premium on the used market.
An SRNE 10K hybrid goes for about $1500.
A used SI and SB combo would be more than twice the price? Still worth it?

And well worth it.
At least until generic Chinese inverters are considered bulletproof.

I dont read of many issues with Sunny Islands or Sunny Boys.

They don't have many issues, but they will break eventually.
I calculated some 32 years MTBF for running 4 or 5 SB SWR2500U for 17 years, with a couple failures.
I've seen a couple error messages when running off-grid driving a VFD (poor PF), recovered on power cycle.
I may have bricked one SB doing something similar; it eventually latches the error and can't be reset.
There are some reports of welded relays in SI, and over-current errors in SB.
I've got a couple units I bought "as-is for parts" that give an error message. A couple others that work just fine.
So long as they work when you get them, should have a long life. Heat an moisture inside are the enemy of any electronics.

You can get 2x SI in a metal box for $4000 delivered (keep doors open or otherwise improve cooling), and several SB at whatever prices. Maybe 24kW worth for $2400 +/-. Plus hardware to hook them up and a relay to disconnect loads when battery low. That gives 11.5kW from battery and up to 35.5 kW depending on sunshine and PV panels. 22kW surge to start motors.

Compare to other systems, SolArk for an HF all in one, the new Midnight 10kW AIO, Midnight Rosie + Barcelona. Schneider. Etc. The lesser brands of course are cheaper, not necessarily comparable.

If you weren't getting bargains on SMA equipment, would be hard to justify the price for an off-grid system. They've been reasonably competitive for grid tie. When I see an eBay seller with several inverters, I ask, "How much for all of them?"

 

[Dave911]

If you have the ability to write an SD card (full size, think it is 2 GB max and FAT32) should be pretty easy, using front panel pushbuttons.
I haven't updated them, have followed step by step to save state to a card and upload for SMA support.

Otherwise, there are RS-485 communication methods. You buy and install a daughter card (same one used when telling older SB 5000US to switch between UL-1741 and offgrid parameters, not needed when always offgrid except one time to set SB parameters). Connect a communication device (discontinued WebBox), and I think that can transfer.

(I did update one TriPower through Sunny Explorer software and Ethernet.)

It looks like the SI 6048US being liquidated due to DC Solar bankruptcy already support an external BMS. Some 5048US from earlier times don't.



Some parameters require installer to enter a "password" which is simply sum of digits of the operating hours it displays.
Some parameters related to UL-1741 require "grid guard code", which you request from SMA and they give if they consider you a "qualified individual". One forum member got that by providing a document from PG&E saying the parameters had to change from UL-1741 to Rule-21.

Sunny Boy similarly require Grid Guard, including to change an old one from UL-1741 to offgrid. One grid guard code works for all SMA equipment, and is a fingerprint showing you're the one who altered settings.

For inverters locked with user & installer passwords you don't know, SMA will provide Personal Unlocking Code, which is actually a code unique to serial number.

You're likely to need Grid Guard and PUK if you buy used Sunny Boys, and want to configure for offgrid.




And well worth it.
At least until generic Chinese inverters are considered bulletproof.



They don't have many issues, but they will break eventually.
I calculated some 32 years MTBF for running 4 or 5 SB SWR2500U for 17 years, with a couple failures.
I've seen a couple error messages when running off-grid driving a VFD (poor PF), recovered on power cycle.
I may have bricked one SB doing something similar; it eventually latches the error and can't be reset.
There are some reports of welded relays in SI, and over-current errors in SB.
I've got a couple units I bought "as-is for parts" that give an error message. A couple others that work just fine.
So long as they work when you get them, should have a long life. Heat an moisture inside are the enemy of any electronics.

You can get 2x SI in a metal box for $4000 delivered (keep doors open or otherwise improve cooling), and several SB at whatever prices. Maybe 24kW worth for $2400 +/-. Plus hardware to hook them up and a relay to disconnect loads when battery low. That gives 11.5kW from battery and up to 35.5 kW depending on sunshine and PV panels. 22kW surge to start motors.

Compare to other systems, SolArk for an HF all in one, the new Midnight 10kW AIO, Midnight Rosie + Barcelona. Schneider. Etc. The lesser brands of course are cheaper, not necessarily comparable.

If you weren't getting bargains on SMA equipment, would be hard to justify the price for an off-grid system. They've been reasonably competitive for grid tie. When I see an eBay seller with several inverters, I ask, "How much for all of them?"

Ha ha...so when I see a volume seller of SMA equipment on Ebay suddenly sell out I might know where they all went!
The Sunny Island 6k looks like about 150 lbs? Have you had good luck shipping those?
Dealing with SD cards is no problem regarding firmware. I was concerned about it being tightly controlled by SMA or requiring special loading software. Some equipment makers can be difficult to deal with. I do industrial controls and programming. PLCs, automation in general, etc. There is some equipment I avoid just because the manufacturer is just too difficult to deal with.
Sounds like SMA is ok.