Can I get some last minute advice before signing contract?

[J.P.M.]

You clearly spoke with an idiot

I found out long ago that there's a high likelihood of that outcome when you call Tesla.

[mikedunkel]

You wont regret it. That new RESU16H is impressive and coupled with the SolarEdge backup interface will get you through the shorter outages without a hiccup. The generator will kick in if the battery is depleted but I'm curious to know more about how the SolarEdge inverter and Generac will communicate and coordinate output when your household draw exceeds the 5kW max output of the inverter. I'm definitely jealous that the new SolarEdge interconnectivity allows your battery to power the entire house and not just a separate backup loads panel.

I'm not sure my installer really knows either. I believe he quoted me too large a generator but when I looked at price differences between the 10kw and the 14kw they were in the noise compared to the overall system cost. Neither of us knows if the generator is binary or variable speed -- ie will it be going full-bore even if the load is minimal or will it be smart enough to spin more slowly and use less fuel when the excess load is say 1-2kw. He also couldn't answer what happens when the grid is down and the sun is shining. Will the generator shut off completely if there's adequate solar production? Maybe somebody here knows and could share.

Regardless, what the installer knows really isn't important because it'll either do what I want or it won't based upon the solaredge software not his knowledge of the system. The installer also said that they're coming out with a 10kw inverter but the ETA is unknown at this point and I don't feel like waiting on promises and maybes.

[Mike90250]

The generator is going to be 3600 RPM. no variation in speed, unless there is bold ad lettering "Inverter Generator".

As to the the rest, the sales droid SHOULD know how the gear operates.

[mikedunkel]

The generator is going to be 3600 RPM. no variation in speed, unless there is bold ad lettering "Inverter Generator".

As to the the rest, the sales droid SHOULD know how the gear operates.

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.

[Mike90250]

>>> is there any way to manually jump start the solar array if I were to ever run out of LP?

Nope, it must sense 240VAC and a nearly infinite Grid Load before it will engage. While it may engage with the generator, if your house loads drop too low, the excess voltage from the inverter may fry your generator. The PV array/Inverter will try to always put out max power, thinking it's feeding the infinite grid

[mikedunkel]

>>> is there any way to manually jump start the solar array if I were to ever run out of LP?

Nope, it must sense 240VAC and a nearly infinite Grid Load before it will engage. While it may engage with the generator, if your house loads drop too low, the excess voltage from the inverter may fry your generator. The PV array/Inverter will try to always put out max power, thinking it's feeding the infinite grid

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.

[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?

[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 .

[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

[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.

[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.

[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.

[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]

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).

[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).