are Hi-mo-5 550 watt panels decent for $140? what other equipment should i look for

[ahreno]

yes, i would be NEM 3 which is 60% below NEM 2. i'm fine with off grid. i just dont want to give PGE any more money. they destroyed my business, property in the fires in 2017. i got a settlement from them, they jack their fucking rates up so i want to use some of the settlement to get out from under them.

 

[ahreno]

did my usage numbers mean anything to you? does the system i'm considering seem like a good plan? the bids i've gotten have mostly been roof mount which is ridiculous cause my roof is shaded and they just doubled the amount of needed panels to compensate. but they were all microinverters and very vague.

 

[OffGridForGood]

I didn't see what you feel would be the monthly total kWh used, but the loads don't jump out at me except for the hot tub - these are often 40-50 Amp loads depending on what size they are, and how the heaters are set up.
Roof mounted PV needs Rapid Shut Down - easiest to do with microinverters, but expensive. If you go ground mount then you don't need rapid shut down. Putting PV in a known shady location is not a good plan, and doubling the PV will not solve the shading problem. Microinverters help with shade issues since every panel can be different output, but the microinverters seem to be prone to failure. not always easy to access them to swap them out either.

Your plan for the large PV is fine as long as the Fronius PV inputs will be adequate for the incoming voltage and current. I assume you have space for the ground mount and don't have significant shading issues.
I took a quick look and saw maybe 20F as the lowest low temp in your area, so this will have minimal impact on the PV VOC typical is to allow about 10% for the lowest low temp.
you may want the panels in series up to a bit below max voltage, and then look at the currents to confirm they fit below the Fronius limits.

With a hot tub and some of the loads you show, you need to check what combination might exceed the 11.4 kW output. In my own set up we left out the electric double oven (on grid) until recently due to the possible combinations of big loads exceeding my inverter output. The oven although a high current item when on, is not actually used that often, or for very long when used, so was not a big monthly cost to leave on utility.

 

[OffGridForGood]

back to the PV question, from post #3,

The Fronius shows nominal 660V and normal MPP range 200-800v (wow 800v)
the current limits for the two MPP inputs are 33A and 18A
From the PV data your panels are 49.8v each at VOC, and 14A Isc
So a single string in series of 12 panels would be just under 600v and 14A - which fits well under the 18A limit for MPP2
and you could have a pair of strings 12 and 12 paralleled into MPP1 and still be well below the 33A limit.
so 24 panels would work well, and you have 'room to grow' with 12 more if you like in the future and have the space.
{note: you can exceed current and the result will be clipping - inverter using less than total current, no damage risk, but never exceed voltage limits}

 

[ahreno]

I didn't see what you feel would be the monthly total kWh used, but the loads don't jump out at me except for the hot tub - these are often 40-50 Amp loads depending on what size they are, and how the heaters are set up.
Roof mounted PV needs Rapid Shut Down - easiest to do with microinverters, but expensive. If you go ground mount then you don't need rapid shut down. Putting PV in a known shady location is not a good plan, and doubling the PV will not solve the shading problem. Microinverters help with shade issues since every panel can be different output, but the microinverters seem to be prone to failure. not always easy to access them to swap them out either.

Your plan for the large PV is fine as long as the Fronius PV inputs will be adequate for the incoming voltage and current. I assume you have space for the ground mount and don't have significant shading issues.
I took a quick look and saw maybe 20F as the lowest low temp in your area, so this will have minimal impact on the PV VOC typical is to allow about 10% for the lowest low temp.
you may want the panels in series up to a bit below max voltage, and then look at the currents to confirm they fit below the Fronius limits.

With a hot tub and some of the loads you show, you need to check what combination might exceed the 11.4 kW output. In my own set up we left out the electric double oven (on grid) until recently due to the possible combinations of big loads exceeding my inverter output. The oven although a high current item when on, is not actually used that often, or for very long when used, so was not a big monthly cost to leave on utility.

interesting. i dont know that i can exactly exclude items from the solar setup. i have my main meter about 100ft from my house and my house is essentially on a 200amp subpanel. I'll check into the wattages of everything a bit more before i buy. there is also a 12kw and a 15kw for $800 more or so. i'm not dead set on fronius either, someone just said they were best, do you have a recommendation?

the roof mounted solar proposals were ridiculous. $50-70k and no reason to do the roof other than being easy. i have 2 acres and a spot about 40 feet from my meter that gets full sun. the local company that actually came out agreed ground mount was best but their proposal was still $30-35k.

yes it doesn't get too cold here. below 20 is quite unheard of. super hot though and not many clouds most of the year.

my monthly usage seems to be hovering around 1000-1200kwh

 

[OffGridForGood]

interesting. i dont know that i can exactly exclude items from the solar setup. i have my main meter about 100ft from my house and my house is essentially on a 200amp subpanel. I'll check into the wattages of everything a bit more before i buy. there is also a 12kw and a 15kw for $800 more or so. i'm not dead set on fronius either, someone just said they were best, do you have a recommendation?

I have seen Fronius in commercial set ups in my area, and they are well regarded here, but I don't have one. The specs look very impressive to me, and I looked up the costs for a pair of 11.4's (bit rich, but I am considering it due to the high PV voltages these support).

There are a couple ways you can go, with the main panel and solar:
You can back-feed into an existing panel and reduce the power that is supplied from the grid, but these "grid tied zero export" systems seem (from what I know) to always suffer from some back feeding, and modern smart meters will pick this up, and result in issues contact from the utility. I was tempted in my own system to do a 'grid-tied-zero-export but then thought about big loads that will suddenley shut off, and result in some export currents, which my smart meter will no-doubt report and I would be in hot water with the (Provincially owned) utility - so I didn't do this route.
The other option - is put a new panel beside your existing one, for solar supplied loads, and move over the circuits that you want on solar. Leave on the utility any that your system may not be able to support - say the hot tub for example - and pay the bill each month for just that, while most of your home runs off the solar. The utility can still supply the AC input side of the inverter, for charging batteries during a cloudy December for example, and this will not back feed to the grid ever.
The other option is what is called a Critical Loads Panel -CLP- which allows either utility or other source (generator or solar) to be the power supply for critical loads like furnace fan, well pump, lights, fridge freezer - and the CLP has separate switches so you can pick and choose at any time which loads are supplied from utility or from your solar. Look up the Reliance 306 as an example - I used this one - and see how this is designed to sit between your utility panel and another power source, originally these were designed to work with a generator, but work the same way with a solar set up. I find the CLP especially handy during low solar time of year, as it lets me easily choose to put some loads back to the utility, that would normally run on solar most of the year in my set up. I didn't look to see if there is a Reliance large enough for a hot tub, but likely there is, and this may be a good option for your set up, so you can with the flip of a switch move this load from utility to solar or back if required.

To be clear about my own set up: I have two dedicated electrical panels for solar loads 'all the time' and I also have the 30 amp Reliance for a few key items (furnace fan, well pump, fridges, freezers and lights in kitchen & bathroom) so I have options for those key items at any time with the Reliance switches. Is this right for you? not sure, but something to consider.

 

[OffGridForGood]

my monthly usage seems to be hovering around 1000-1200kwh

From the PV Watts table you likely need some additional input (grid or generator) during Dec and January, and depending on battery size compared to loads used, a week of rain/cloudy weather would leave you short other times of the spring/fall - although you noted 'not a lot of cloudy weather' so maybe your okay. The point of the AC input to and AIO is that the inverter can charge up the batteries when needed - if needed. Yes this results in a bill from the utility, but is low cost insurance compared to overbuilding the whole solar PV side just to get through Dec-Jan without a bill.

I run my shop and home together on 19kW output - I try to keep under 16kW to ease the load on my equipment.
I am not sure 11.4kW is going to run your home. It comes back to the power audit, and what might be running all at the same time.
11,400W / 240v = 47.5A max. It doesn't take too many items of 20A each to exceed 47.5 and motors/pumps have higher initial loads during start up to consider. If the Fronius has load shaving capability you may be good, otherwise I would consider the trade off of: larger inverter or some loads remain on utility, and run the numbers.

On the battery side, you said two power walls - I believe those are 7.5 or 13.5 kwh batteries - depends which PW model if I remember correctly.
27 kWh of battery is not bad for running a home - 1200kWh/mth is about 40kWh per day so the 27kWh would normally get you through the night and have some room for a poor cloudy day. If you can count on decent solar input nearly every day, you may be okay with 27kWh.
{in my system I run a business and my home both on one solar set up, and can't be down during Mon-Fri, I can have three days of clouds in a row, so I built a bigger battery to compensate.

 

[ahreno]

but even if it doesn't

From the PV Watts table you likely need some additional input (grid or generator) during Dec and January, and depending on battery size compared to loads used, a week of rain/cloudy weather would leave you short other times of the spring/fall - although you noted 'not a lot of cloudy weather' so maybe your okay. The point of the AC input to and AIO is that the inverter can charge up the batteries when needed - if needed. Yes this results in a bill from the utility, but is low cost insurance compared to overbuilding the whole solar PV side just to get through Dec-Jan without a bill.

I run my shop and home together on 19kW output - I try to keep under 16kW to ease the load on my equipment.
I am not sure 11.4kW is going to run your home. It comes back to the power audit, and what might be running all at the same time.
11,400W / 240v = 47.5A max. It doesn't take too many items of 20A each to exceed 47.5 and motors/pumps have higher initial loads during start up to consider. If the Fronius has load shaving capability you may be good, otherwise I would consider the trade off of: larger inverter or some loads remain on utility, and run the numbers.

On the battery side, you said two power walls - I believe those are 7.5 or 13.5 kwh batteries - depends which PW model if I remember correctly.
27 kWh of battery is not bad for running a home - 1200kWh/mth is about 40kWh per day so the 27kWh would normally get you through the night and have some room for a poor cloudy day. If you can count on decent solar input nearly every day, you may be okay with 27kWh.
{in my system I run a business and my home both on one solar set up, and can't be down during Mon-Fri, I can have three days of clouds in a row, so I built a bigger battery to compensate.

yes, 13.5 kWh each. they're free from the power company so i can't complain. be interesting to see how it helps / works.

i dont want to get too complicated of a system going and don't really see myself doing a second panel. it's funny cause i literally just sold a reliance panel i've had collecting dust for like 5 years! i'd either get bigger or more inverters to handle my shit or not do it at all or something.

even if it doesn't have load shaving (i emailed them to ask, i didn't see anything in their specs) it would just turn the inverter off and use normal grid power wouldn't it? thats totally fine with me. i can't see that many times of using that much power concurrently though i will definitely check what uses what before i buy any inverters. even spending the extra $800 for their bigger 15kw wouldnt break my budget and that'd give me 60amps. i should just burn the hot tub.

it'd be a lot of work to try to split loads to different circuit panels. i'd have to feed another power line into my house which doesn't sound fun, even if the conduit has enough room.

thank you for your conversation, its helpful

 

[OffGridForGood]

but even if it doesn't

yes, 13.5 kWh each. they're free from the power company so i can't complain. be interesting to see how it helps / works.

free is always good!

i dont want to get too complicated of a system going and don't really see myself doing a second panel. it's funny cause i literally just sold a reliance panel i've had collecting dust for like 5 years! i'd either get bigger or more inverters to handle my shit or not do it at all or something.

Got it, check what combination of large loads could be on at once, but my gut feeling is 11.4kW will not be enough so consider two or the larger units you noted earlier for a few hundred more.

even if it doesn't have load shaving (i emailed them to ask, i didn't see anything in their specs) it would just turn the inverter off and use normal grid power wouldn't it? thats totally fine with me.

It will not turn off, it will switch from inverter supply (solar/battery) to by-pass mode - ie utility passing through your inverter to run the loads. There should be settings in the inverter that will allow it to automatically return to inverting mode when the loads reduce again.

i can't see that many times of using that much power concurrently though i will definitely check what uses what before i buy any inverters. even spending the extra $800 for their bigger 15kw wouldnt break my budget and that'd give me 60amps.

60 amps is more likely to handle a whole house without issue.

i should just burn the hot tub.

Yeah they are power hogs for sure.

it'd be a lot of work to try to split loads to different circuit panels. i'd have to feed another power line into my house which doesn't sound fun, even if the conduit has enough room.

Not sure why you need another power line? The utility line could remain and feed the existing panel, and a new solar supplied panel could go right beside it - if you have space. Then you move the branch circuits one by one from the existing panel to the new panel. The end result is the original panel has only one branch to supply the inverter in put for by-pass and battery charging from utility.
I am not an electrician, and not up on all NEC-requirements, however seems this arrangement has been discussed by many other members, and is permited.

thank you for your conversation, its helpful

Glad to help!, hope to see what you end up with for your set up.
Now I have a copy of the Fronius manual on my laptop, calling to me...

 

[ahreno]

free is always good!

Got it, check what combination of large loads could be on at once, but my gut feeling is 11.4kW will not be enough so consider two or the larger units you noted earlier for a few hundred more.

It will not turn off, it will switch from inverter supply (solar/battery) to by-pass mode - ie utility passing through your inverter to run the loads. There should be settings in the inverter that will allow it to automatically return to inverting mode when the loads reduce again.

60 amps is more likely to handle a whole house without issue.

Yeah they are power hogs for sure.

Not sure why you need another power line? The utility line could remain and feed the existing panel, and a new solar supplied panel could go right beside it - if you have space. Then you move the branch circuits one by one from the existing panel to the new panel. The end result is the original panel has only one branch to supply the inverter in put for by-pass and battery charging from utility.
I am not an electrician, and not up on all NEC-requirements, however seems this arrangement has been discussed by many other members, and is permited.

Glad to help!, hope to see what you end up with for your set up.
Now I have a copy of the Fronius manual on my laptop, calling to me...

I have to read all this yet, I'm heading to buy the panels, would you do 26 or 24? Leaning towards 26 just cause it's easier to oversize a bit now than addon later. And $270 doesn't break the bank. Unless the inverter can't take the extra 2 but I think it can

 

[OffGridForGood]

From the spec sheet you posted they likely can take the extra panels, or you have a couple spares just in case. Either way not a bad thing if the budget has room. It seems hard to match any panels a year or two after purchase - can be frustrating if you need a replacement, so extra is not a bad thing.