Can I get some last minute advice before signing contract?

[OCJ]

It seems to me you can achieve your stated goal of this:

My desired system performance is to basically run the entire house during a power outage as if there wasn't a power outage, assuming daytime and full system performance.

By letting your batteries charge to full and leaving them there. Perhaps periodically discharge them to 50% and recharge monthly but not on a daily basis.

If your goal was ROI and using your batteries daily that would be another analysis. You would need your solar output in kWh to be greater than your daily 24-hour usage + losses in order to cycle your batteries to full every day.

Right now, the only reason to get solar (assuming you have grid access) is to make an expensive virtue signaling statement.

This might be the case where you are but it's certainly not the case where I am. I'm in SDG&E so I have $.70 peak pricing, TOU, and net metering. My ROI with just panels would have been around 5-6 years, with the battery (Powerwall+) probably a couple more years. I didn't buy the battery for ROI, though, I bought it for convenience and control over how and when I send to the grid. Plus I may get some or all of it paid for which again drops my ROI. Your blanket statement does not apply to all areas of the country.

[mikedunkel]

Now that you have 20/20 hindsight help the next guy before he has the same unfortunate outcome. Looking back how could this been prevented?

My issues are 2-fold. As Soby mentioned the state you live in matters, if the state lets the utility screw you on net metering and there are no state level incentives then making your money back is a pipe dream. Issue 2 is storage, because our net metering sucks I purchased 32KWH of storage which added roughly 33% to the cost of my install. For me, the storage was so my system wouldn't shut off in the event of a grid outage, not because of my area's terrible net metering. Even with crummy net metering the batteries don't do a whole lot. The only time my batteries fully charge is on sunny days when the AC isn't running. On those occasions I really don't use that much electricity at night either so I don't even fully discharge the batteries. During AC months (probably 7 months of the year here) even with full sun the batteries won't fully charge -- heck, they usually don't even charge 10% above whatever level I have set as their floor. Without the batteries the system would've eventually paid for itself but that $$ would've been far better used as an investment.

Right now, the only reason to get solar (assuming you have grid access) is to make an expensive virtue signaling statement. Maybe if the incentives were right, you don't mind if your system turns off during a grid outage, and you already have an electric car then you could skip the batteries and you'd rarely send anything back to the grid (or if you were fairly paid for what you sent back).

One other thing which is difficult to assess but has bit me in the butt. I've had mostly negative experience with Solar Edge, LG, and Suncatcher of Atlanta. That's 0 for 3 on the solar companies I've worked with 1st hand. I looked at Tesla and a couple other local installers and I thought I selected the best of what was available. Frankly I feel like I bought a ticket on Spirit, these companies are not reliable, responsive, and don't even understand their own products. The technology, local expertise, and competition just aren't there yet. The news wants to make you think solar is a responsible choice, but it's just not there yet. Too expensive to buy, way too little return on investment, and poor customer service all around. I'd skip it entirely if I had this knowledge a year ago.

[Mike 134]

Now that you have 20/20 hindsight help the next guy before he has the same unfortunate outcome. Looking back how could this been prevented?

[soby]

Regarding your three f*cks:
1) Your utility net metering sucks. Your state is to blame for that. Without significantly more battery storage, you have no choice but to give the excess power to your utility at a significant discount.

2) You can register for a SolarEdge installer account and your installer can add that login as an admin on only your site. That’s what my installer did for me early on. I have full access to the battery storage profiles that sync online. If your power and internet go out, the system will automatically go into backup mode and there isn’t much configuration involved.

3) Again, your state is to blame. There can be state/utility incentives for both solar panels and battery storage that help accelerate the years to break even. Your utility wants you to stay dependent and makes sure your lawmakers keep it that way.

[mikedunkel]

Thought I'd report back a year after the fact. The process took a very long time, I think my first consult was May, they started installation in June, completed installation in September with 1 faulty battery, got approval to operate mid-September, and finally got the faulty battery replaced in May -- 1 year from consult to fully operational.

My initial thought is "f*ck". I spent a lot on this system and it will never do what I wanted. In the winter I can generate up to 75kw of power in a day which is far in excess of what I use. Since the generation and my usage don't happen at the same time I still end up buying some from the utility and selling a bunch back at about a 4:1 cost ratio. Of course there are also a lot of clouds in the winter so while my peak generation is higher, my average generation is a lot lower. In the summer I'm lucky to get more than 50kw in a day due to intermittent cloud cover and decreased efficiency of the panels in the heat. My batteries don't ever charge since I use up all the generated electricity to run the air conditioning and pool pump -- I'd need a LOT more panels to compensate which would be complete overkill in the winter.

My 2nd thought is "f*ck". While I paid for the system, it's not really mine. Solar Edge and my installer still have full control over the modes my system operates in and if there's a problem (which there often is) there's nothing I can do about it without assistance from one of these companies. Without internet I'm not even sure the system will keep running, and I'm 100% certain that the 1st hiccup without internet and it's down. This completely defeats the purpose of having a solar system as a long term backup in the event of a major disaster. I get a major fault in my inverters at least once per quarter that requires help from above, this thing will never be a prepper's salvation.

My 3rd thought is "f*ck". This system will NEVER pay for itself. After the federal tax credit it cost about $45k. I am saving roughly $130/month in the summer and $50/month in the winter on my electricity. Even if I round way the f up to an average of $150/month saved we're talking 25 years to pay for itself. But since I'm not even saving that much on my best month and the equipment won't work as well the older it gets this entire endeavor has been a huge money loser. Potential saving grace would be if state law changed and I was able to sell electricity back to the utility at a comparable rate to which I pay for it. Another way this could be better is if the cost of electricity goes up drastically. Finally, it should help my property's resale value for a buyer as ignorant as I was when I decided to add solar to my home .

If I had to do it over, I'd have just purchased a generator that ties into my buried CNG tank and called it good.

[Roy Shultz]

To mods, I think I had too many edits and got flagged for spam. You can delete the old post assuming this one works.

Thank you for your reply. I hadn't considered the insurance angle, do you know what is driving that?

To get my desired system performance I'll have to purchase (2) 7.6kw inverters, (2) backup modules, and (2) RESU-16 batteries. It didn't make sense to have >15kw of inverter capacity and only 11.3kw of panels so I had them max out my roof and I'll now have (38) 365w solaria panels for 13.8kw of capacity. I probably need to call Solar Edge and verify, but my installer is now telling me that if I get a generator it will only power one of my two electrical panels due to being wired through the solar edge backup module. Since my costs went up pretty considerably, the generator would only power half the house, and they're charging me way too much for the generator I'm considering dumping it from the system and just going panels and battery. As I understand it under grid outage conditions ditching the generator will lose me a little capacity on cloudy days and will limit me to battery power at night and that's it -- can anyone verify my accuracy here?

One uncertainty I have under outage conditions (assume sufficient sunlight): will my PV power the batteries and the batteries power my home, or will my PV directly power the home with any excess going to the batteries? Since the batteries can only hack 5kw and it'll be one battery per inverter/200A service, they may not be enough to run my air conditioners but if the PV is directly powering the house I should be fine (I am upgrading my 23 year old HVAC to Bosch variable speed AC units, that should be a major help in my start-up surge and constant use draw).

That is an awesome grid, and I would think it would do the job for you. The batteries will give you 32kw total usable energy at night (if full before nightfall) and the system is maxed out the best it can be for doing the job for you. I have an Enphase system and only 20.2 battery total (10% of that unusable as it won't completely run batteries dead), and if they don't get filled up good before nightfall or it rains late eve., they won't last until morning with our Florida high nighttime temps with cycling of the AC. Remember my grid is only 9k, so I do not have the generating capability that you will have, nor the extra storage you will have with this setup. From what I know, this is as good as you can get to have the ability to keep and use all your energy and get enough in the batteries to last the night. You will be tier 2 though, so I would check with your home insurance on that matter and question your sales rep. as to the possible extra hoops you may have due to going to tier 2 in regards to the power company. The insurance angle is what I believe is the power company and government just trying to limit your independence. That is my opinion. As far as the batteries and grid providing the home during an outage, adding the batteries is a huge plus, and although you don't get much amperage out of the grid, the 1.2 or so per panel (AC) times 38 will do you well during the day if outage, and your batteries should keep you running ok, but they should put in a sub panel isolating huge loads - electric dryer, water heater, stove, and if you don't have it already I would buy a hybrid water heater as it will save you a bunch of energy usage, and mine helps a bunch to cool the garage as it acts as an air cond. pulling in heat and putting out cold air. My outside unit only draws 22 amps, which is pretty good but not variable speed, but with your new unit being variable speed, you should be able to use your main AC, and will help with your night usage of battery immensely.

[mikedunkel]

Actually, you can go up to 11.76 DC on your grid before you go over the 10K limit AC on tier 1. If you opt to go for the 13.1 system this would put you into a tier 2 which may cause you headaches on getting it done with your power company as they may require you to jump through more hoops to get it installed, and also will cost you more on your homeowners insurance as you will be required to carry more liability coverage. In our state of Florida, it goes from 300k to 1 million in liability coverage which will increase your costs on that, and varies depending on your carrier. I am a solar sales rep. and will get as close to the 11.76 as possible to maximize generation, but stay tier 1. I sell solar edge systems and you should have 2 inverters, and 2-7600 inverters is NOT overkill as somebody here has stated and I will explain why. I have a 9k grid system which at maximum produces 7.1 kw. A 13kw system would produce far more than the 7600 AC maximum output of the inverter, so it's not hard to do the math on requiring 2, and they are telling you correctly. 1 10k inverter would work, but system would be better and less strain on inverters if you used 2, and using the 7600's is forward thinking as you would get about 3/4 of your production in the event one of them went down. I would want 2 inverters anyhow, as this would keep your system running if one did fail for any reason, although you would get the most out of the one that is running, but would lose a good bit of generation until other one was replaced, at least at maximum sun, Just some thought on that. Also, with my company I can add on the warranty coverage to get 25 years on the inverters, they only offer 12 years on those, and it's not that expensive at all. As far as the batteries are concerned I can assure you that you need plenty to keep you in power overnight if there is an outage. It may not be as big of an issue if you live where night temps aren't high, but here in Florida the A/C unit runs quite a bit at night so I need plenty of battery. I can sell you a 22k Generac installed for 11 grand and change installed, so yea, your right, that is overpriced on that. must be an error somehow. That would be a great option to get one nice size battery and a generator as it would power your home once battery lost power, you can set it to run to charge battery and power home at night once battery got low, but might use a good bit depending, and the reality is gas is cheaper than electric. With the 11.3 system though, you would recommend 2 inverters as your top production will be over 7600 AC, thus cutting your available grid power input, unless you went to the 10k inverter.

To mods, I think I had too many edits and got flagged for spam. You can delete the old post assuming this one works.

Thank you for your reply. I hadn't considered the insurance angle, do you know what is driving that?

To get my desired system performance I'll have to purchase (2) 7.6kw inverters, (2) backup modules, and (2) RESU-16 batteries. It didn't make sense to have >15kw of inverter capacity and only 11.3kw of panels so I had them max out my roof and I'll now have (38) 365w solaria panels for 13.8kw of capacity. I probably need to call Solar Edge and verify, but my installer is now telling me that if I get a generator it will only power one of my two electrical panels due to being wired through the solar edge backup module. Since my costs went up pretty considerably, the generator would only power half the house, and they're charging me way too much for the generator I'm considering dumping it from the system and just going panels and battery. As I understand it under grid outage conditions ditching the generator will lose me a little capacity on cloudy days and will limit me to battery power at night and that's it -- can anyone verify my accuracy here?

One uncertainty I have under outage conditions (assume sufficient sunlight): will my PV power the batteries and the batteries power my home, or will my PV directly power the home with any excess going to the batteries? Since the batteries can only hack 5kw and it'll be one battery per inverter/200A service, they may not be enough to run my air conditioners but if the PV is directly powering the house I should be fine (I am upgrading my 23 year old HVAC to Bosch variable speed AC units, that should be a major help in my start-up surge and constant use draw).

[mikedunkel]

Actually, you can go up to 11.76 DC on your grid before you go over the 10K limit AC on tier 1. If you opt to go for the 13.1 system this would put you into a tier 2 which may cause you headaches on getting it done with your power company as they may require you to jump through more hoops to get it installed, and also will cost you more on your homeowners insurance as you will be required to carry more liability coverage. In our state of Florida, it goes from 300k to 1 million in liability coverage which will increase your costs on that, and varies depending on your carrier. I am a solar sales rep. and will get as close to the 11.76 as possible to maximize generation, but stay tier 1. I sell solar edge systems and you should have 2 inverters, and 2-7600 inverters is NOT overkill as somebody here has stated and I will explain why. I have a 9k grid system which at maximum produces 7.1 kw. A 13kw system would produce far more than the 7600 AC maximum output of the inverter, so it's not hard to do the math on requiring 2, and they are telling you correctly. 1 10k inverter would work, but system would be better and less strain on inverters if you used 2, and using the 7600's is forward thinking as you would get about 3/4 of your production in the event one of them went down. I would want 2 inverters anyhow, as this would keep your system running if one did fail for any reason, although you would get the most out of the one that is running, but would lose a good bit of generation until other one was replaced, at least at maximum sun, Just some thought on that. Also, with my company I can add on the warranty coverage to get 25 years on the inverters, they only offer 12 years on those, and it's not that expensive at all. As far as the batteries are concerned I can assure you that you need plenty to keep you in power overnight if there is an outage. It may not be as big of an issue if you live where night temps aren't high, but here in Florida the A/C unit runs quite a bit at night so I need plenty of battery. I can sell you a 22k Generac installed for 11 grand and change installed, so yea, your right, that is overpriced on that. must be an error somehow. That would be a great option to get one nice size battery and a generator as it would power your home once battery lost power, you can set it to run to charge battery and power home at night once battery got low, but might use a good bit depending, and the reality is gas is cheaper than electric. With the 11.3 system though, you would recommend 2 inverters as your top production will be over 7600 AC, thus cutting your available grid power input, unless you went to the 10k inverter.

Thank you for your reply. I hadn't considered the insurance angle, do you know what is driving that?

To get my desired system performance I'll have to purchase (2) 7.6kw inverters, (2) backup modules, and (2) RESU-16 batteries. It didn't make sense to have >15kw of inverter capacity and only 11.3kw of panels so I had them max out my roof and I'll now have (38) 365w solaria panels for 13.8kw of capacity. I probably need to call Solar Edge and verify, but my installer is now telling me that if I get a generator it will only power one of my two electrical panels due to being wired through the solar edge backup module. Since my costs went up pretty considerably, the generator would only power half the house, and they're charging me way too much for the generator I'm considering dumping it from the system and just going panels and battery. As I understand it under grid outage conditions ditching the generator will lose me a little capacity on cloudy days and will limit me to battery power at night and that's it -- can anyone verify my accuracy here?

One uncertainty I have under outage conditions (assume sufficient sunlight): will my PV power the batteries and the batteries power my home, or will my PV directly power the home with any excess going to the batteries? Since the batteries can only hack 5kw and it'll be one battery per inverter/200A service, they may not be enough to run my air conditioners but if the PV is directly powering the house I should be fine (I am upgrading my 23 year old HVAC to Bosch variable speed AC units, that should be a major help in my start-up surge and constant use draw).

[Roy Shultz]

Hello and thanks for looking,

I got quotes from 4 companies (3 local and Tesla) and selected a local company to do my grid-tied system and I'm trying to determine if I need to go with a single or 2-inverter build. My top priority is performance and my 2nd is cost and as everyone knows these two priorities are in direct conflict with each other. I'm willing to spend what it takes to achieve my goals but I don't want a system that has so much excess capacity that I'm constantly selling power back to the utility at pennies on the dollar (my EMC pays like 2 cents a KWH vs charging me 10 cents/KWH).

My desired system performance is to basically run the entire house during a power outage as if there wasn't a power outage, assuming daytime and full system performance. Last year my very highest hourly usage was 10.24 KW, the year prior it was around 12 KW. Most of the time my usage is significantly lower, and in addition to adding solar I'm getting new windows, going from blown to spray-in foam in the attic, and filling-in my 30,000 gallon swimming pool (2 pumps) so there is going to be an unknown but fairly significant decrease in my consumption.

The 2 systems my installer has proposed are a 13.1KW system with 2 StorEdge SE7600 inverters and 2 RESU16H batteries, and an 11.3KW system with a single SE7600 inverter and 2 RESU16H batteries. His initial recommendation was for the smaller system and only a single battery but I told him that having power in the event of an extended grid failure was more important to me than ROI so this company is not trying to gouge me, the extra battery and a quote for a bigger system were at my request and not their prompting.

So, will the single inverter be able to handle my desired output or will I need to spend another extra $9k (pre tax credit) for the additional inverter and 1.8kw of panels?

BTW, I am NOT interested in what brand of panel, inverter, or battery you think is better than what I've selected. I've gotten my quotes and my decision is final regarding the company and products. The only question is how big I need to go .

Thanks for your time.

Actually, you can go up to 11.76 DC on your grid before you go over the 10K limit AC on tier 1. If you opt to go for the 13.1 system this would put you into a tier 2 which may cause you headaches on getting it done with your power company as they may require you to jump through more hoops to get it installed, and also will cost you more on your homeowners insurance as you will be required to carry more liability coverage. In our state of Florida, it goes from 300k to 1 million in liability coverage which will increase your costs on that, and varies depending on your carrier. I am a solar sales rep. and will get as close to the 11.76 as possible to maximize generation, but stay tier 1. I sell solar edge systems and you should have 2 inverters, and 2-7600 inverters is NOT overkill as somebody here has stated and I will explain why. I have a 9k grid system which at maximum produces 7.1 kw. A 13kw system would produce far more than the 7600 AC maximum output of the inverter, so it's not hard to do the math on requiring 2, and they are telling you correctly. 1 10k inverter would work, but system would be better and less strain on inverters if you used 2, and using the 7600's is forward thinking as you would get about 3/4 of your production in the event one of them went down. I would want 2 inverters anyhow, as this would keep your system running if one did fail for any reason, although you would get the most out of the one that is running, but would lose a good bit of generation until other one was replaced, at least at maximum sun, Just some thought on that. Also, with my company I can add on the warranty coverage to get 25 years on the inverters, they only offer 12 years on those, and it's not that expensive at all. As far as the batteries are concerned I can assure you that you need plenty to keep you in power overnight if there is an outage. It may not be as big of an issue if you live where night temps aren't high, but here in Florida the A/C unit runs quite a bit at night so I need plenty of battery. I can sell you a 22k Generac installed for 11 grand and change installed, so yea, your right, that is overpriced on that. must be an error somehow. That would be a great option to get one nice size battery and a generator as it would power your home once battery lost power, you can set it to run to charge battery and power home at night once battery got low, but might use a good bit depending, and the reality is gas is cheaper than electric. With the 11.3 system though, you would recommend 2 inverters as your top production will be over 7600 AC, thus cutting your available grid power input, unless you went to the 10k inverter.

[mikedunkel]

In case anybody cares or is in a similar situation, I was mistaken in my previous post about Solar Edge insulating themselves, with enough patience and going through all the menus I eventually spoke with a very helpful Solar Edge representative on Friday and it sounds like for separate 200A services, the only way I can have my mini-powerplant where I can continue to generate solar based electricity for my entire home during a grid outage is to have parallel systems -- 2 backup modules, 2 inverters, and 2 batteries. I will need to call them back and ask if the single generator can be wired to both backup modules so it would provide any additional power required during an outage.

[mikedunkel]

Having the backup interface with a full battery, solar (with full sun) and a generator is different than having a generator and solar (with full sun). The generator is stupid while the backup interface, solar inverter and Resu battery all communicate with each other. In whole house backup mode, the backup interface can make a decision to turn the generator on or off based upon circumstances (battery level, load, etc). If the battery was at 100%, I suspect the backup interface would kick on the generator after battery gets down to x%.

I am in the process of getting a generator; I already have solar with a string inverter (no battery). I don't have a backup interface, but will have an ATS. For the generator, I am using a knowledgeable installer that also did my solar. When the power goes out, my inverter will be off (line side tap) and will be isolated from the generator. Then the generator turns on.

From the Solar Edge document

Energy Hub Inverter and Backup Interface FAQs

Q: Can the Energy Hub and Backup Interface provide backup without a battery (PV-only)?
A: No. Although the system may operate, it is not supported and results will vary.

Q: Can more than one Backup Interface be installed, for example, on split 400A main panel with two separate 200A main breakers?
A: Yes. One Backup Interface can be used for each 200A sub-panel

This is a great find. SolarEdge insulates themselves pretty well from the general public, I'm going to try and call their customer support today to see what's going on. I'm really worried my installer just wants to get everything up on the roof and when it doesn't work out it'll be my problem not theirs. Fortunately I haven't paid them so I still have a little leverage.

[soby]

Oddly enough they're all located outside and unlocked, anybody could come up to my home and throw the switches leaving me in the heat and dark .

Even though my main distribution panel is in the basement, there is a 200a breaker at my meter outside. I keep forgetting to put a padlock on that access door so it's a little harder to kill the power to my house.

Q: Can more than one Backup Interface be installed, for example, on split 400A main panel with two separate 200A main breakers?
A: Yes. One Backup Interface can be used for each 200A sub-panel

From this Q&A, I think it's safe to treat each 200a breaker as its own separate branch. The only problem is that a single inverter/battery/generator combo will only feed one of the 200a branches. Having two independent inverters each with its own battery would actually be ideal but I'm not sure how a single generator could interface with both inverters. That is a question for SolarEdge.

[oregon_phil]

The generator has a built in circuit breaker but I do wonder where the excess panel array electricity will go. Its really no different than if I had a battery and it was full; the power has to go somewhere, they have to have figured this out but the salesman is having difficulty explaining it to me.

Having the backup interface with a full battery, solar (with full sun) and a generator is different than having a generator and solar (with full sun). The generator is stupid while the backup interface, solar inverter and Resu battery all communicate with each other. In whole house backup mode, the backup interface can make a decision to turn the generator on or off based upon circumstances (battery level, load, etc). If the battery was at 100%, I suspect the backup interface would kick on the generator after battery gets down to x%.

I am in the process of getting a generator; I already have solar with a string inverter (no battery). I don't have a backup interface, but will have an ATS. For the generator, I am using a knowledgeable installer that also did my solar. When the power goes out, my inverter will be off (line side tap) and will be isolated from the generator. Then the generator turns on.

From the Solar Edge document

Energy Hub Inverter and Backup Interface FAQs

Q: Can the Energy Hub and Backup Interface provide backup without a battery (PV-only)?
A: No. Although the system may operate, it is not supported and results will vary.

Q: Can more than one Backup Interface be installed, for example, on split 400A main panel with two separate 200A main breakers?
A: Yes. One Backup Interface can be used for each 200A sub-panel

[mikedunkel]

Do the 200a lines separate? Do you have two independent 200a distribution panels or do both 200a lines feed the same panel?

I'm not entirely certain as I'm not an electrician and I didn't build the house. I have 2 40 slot panels in my basement and a 3rd 24 slot panel in my detached shop. I believe I have 200A service to one 40 slot panel and 200A service shared by my 2nd 40 slot and 3rd 24 slot panels. I have 2 separate 200A service panels with 100A siphoned off one of them for the detached shop. Oddly enough they're all located outside and unlocked, anybody could come up to my home and throw the switches leaving me in the heat and dark .

[soby]

That makes sense. I finally got the specs on the generator, it is 3600 RPM with a full and half capacity operating mode. Looks like the half mode is for test purposes only, they're not advertising any intelligence in the system. What I did just notice is the 10kw system's LP consumption is less than half the 14kw system so I might just downsize in order to conserve fuel.

Finally getting my install today and of course, there's a problem. Turns out I have 2 separate 200A services into my home, apparently the battery interface can only deal with a single service so we had to eliminate the battery from the system. It will be just the solar and the generator.

The installer said the way the system works in a power outage is the generator will turn on first. That will power the solar inverter which will enable my solar array. With no battery this means that if I were to run out of LP there would be no power source to my inverter and I'd be as out of electricity as the guy next door with no panels at all. I really want a zombie apocalypse option where I could keep my refrigerator/freezer going indefinitely, is there any way to manually jump start the solar array if I were to ever run out of LP?

Alternatively, is there another brand which will be able to incorporate the solar array, battery, and generator on my dual 200A service system?

and late breaking news...

Based on the unknowns I sent the installer home so I wouldn't be rushed into a decision I don't fully understand or necessarily want.

Do the 200a lines separate? Do you have two independent 200a distribution panels or do both 200a lines feed the same panel?