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

A

ahreno

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Joined
Apr 17, 2024
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Location
redwood valley
I am probabloy grabbing 25 Hi-mo-5 550 watt panels off marketplace. brand new. Not sure what else i need for a grid tie / battery backup system. I'm already getting two tesla power wall 2's installed for free thru my power company.

I was suggest a 11.4kW Fronius inverter would match well. but i dont know what else i need for a ground mount setup. any help? are the panels good enough for the price? they're about half the price of other panels i was quoted.
 
$140/550W = $0.25/W which is pretty decent cost per W.
Some members have reported better - as low as $0.17/ W IIRC, on new, and then there is the used market on PV that can be very low, but not new.
I don't recall details about the Hi-Mo - If I remember correctly those are Longi brand, which I was looking at myself but ended up gettting a bit better delivered price on JA 550's (in my corner of the world).

Generally you want to plan the whole system out and know what will work before you buy anything.
The normal approach is to start with an audit of your loads, and then size inverters, PV and ESS from there.
There is a good spreadsheet in the resources section of the forum.
For the PV and inverter part:
Start with the MPP input limits for the Fronius inverter - VOC limit and current limit
Then find the PV specs - Max VOC and IMP so the strings can be calculated - you show redwood valley CA - what is the lowest possible temperature - this has effect on PV VOC.
 
ive had a few quotes from solar companies, they all come up with about a 7.5kw system for my needs but i'd like to oversize so i dont have to watch my AC usage and i'm adding a swimming pool. the panels popped up for a good price, almost half the price of other panels i've been quoted. if it's not a great deal i dont need to jump on it. I dont want to go with used panels really.

Inverter:

1713406792752.png

panels (right colum)

1713406910322.png
 
ahreno said:
I am probabloy grabbing 25 Hi-mo-5 550 watt panels off marketplace. brand new. Not sure what else i need for a grid tie / battery backup system. I'm already getting two tesla power wall 2's installed for free thru my power company.

I was suggest a 11.4kW Fronius inverter would match well. but i dont know what else i need for a ground mount setup. any help? are the panels good enough for the price? they're about half the price of other panels i was quoted.
Click to expand...
They are a pretty solid price imo. Panels have been getting cheaper, there’s a place in Vegas selling pallets right now for 17c/w. They are only 370w panels though. You’d use numerically more panels, footprint may not be a ton different though. The last 500+ watt panels I looked at were 8ft tall!
 
yeah, good call on the size. these panels are 7.47ft long. which i'm not sure if it really matters other than for handling them with one person!
G00SE said:
They are a pretty solid price imo. Panels have been getting cheaper, there’s a place in Vegas selling pallets right now for 17c/w. They are only 370w panels though. You’d use numerically more panels, footprint may not be a ton different though. The last 500+ watt panels I looked at were 8ft tall!
Click to expand...
 
ahreno said:
ive had a few quotes from solar companies, they all come up with about a 7.5kw system for my needs but i'd like to oversize so i dont have to watch my AC usage and i'm adding a swimming pool. the panels popped up for a good price, almost half the price of other panels i've been quoted. if it's not a great deal i dont need to jump on it. I dont want to go with used panels really.
Click to expand...
A/C and pool pumps are power hogs, other items to consider in your system are Elect HWT, hot tub, Elect clothes Dryer, Stove/Range etc. Your monthly electrical utility bill will tell you past consumption monthly averages, but doesn't tell you the peak electrical output you may need.
A typical home has a 200A 240v service = 48kW peak available, ie more than 4x the 11kW output Inverter. You will need to consider max output for your situation and make decisions about powering some loads from the utility or the inverter or both.
Go to PVwatts online and plug in your location and 7.5kW PV and the calculator will tell you the average monthly solar you can expect* - be aware PVWatts will over-estimate if you have shading or obstructions. Take the monthly values and divide by 30 for daily average values.
I wish I could buy new 550W panels here for 0.25/W (USD) delivered, living out in the sticks has down consequences.
 
OffGridForGood said:
A/C and pool pumps are power hogs, other items to consider in your system are Elect HWT, hot tub, Elect clothes Dryer, Stove/Range etc. Your monthly electrical utility bill will tell you past consumption monthly averages, but doesn't tell you the peak electrical output you may need.
A typical home has a 200A 240v service = 48kW peak available, ie more than 4x the 11kW output Inverter. You will need to consider max output for your situation and make decisions about powering some loads from the utility or the inverter or both.
Go to PVwatts online and plug in your location and 7.5kW PV and the calculator will tell you the average monthly solar you can expect* - be aware PVWatts will over-estimate if you have shading or obstructions. Take the monthly values and divide by 30 for daily average values.
I wish I could buy new 550W panels here for 0.25/W (USD) delivered, living out in the sticks has down consequences.
Click to expand...
Good call. The inverter will feed the batteries and then the batteries feed the house right?
 
ahreno said:
Good call. The inverter will feed the batteries and then the batteries feed the house right?
Click to expand...
I am not too familiar with the Fronius, but if it is a typical AIO set up, it will have a SCC (solar charge controller) and Inverter (converts DC battery to AC to feed household current) and will also be able to by-pass AC current from a Utility source (to feed loads) while using the Inverter circuit to charge the DC battery from the AC source.

All this to say:
When there is solar, the AIO will accept DC power from the PV array, and use it to charge the batteries/power AC loads.
When there is no solar, the AIO takes DC power from the battery bank and uses it to power AC loads,
When there is no solar and battery drops below a threshold value, the AIO takes Utility power and passes it through to power loads, plus converts to DC to charge the battery bank.
 
OffGridForGood said:
I am not too familiar with the Fronius, but if it is a typical AIO set up, it will have a SCC (solar charge controller) and Inverter (converts DC battery to AC to feed household current) and will also be able to by-pass AC current from a Utility source (to feed loads) while using the Inverter circuit to charge the DC battery from the AC source.

All this to say:
When there is solar, the AIO will accept DC power from the PV array, and use it to charge the batteries/power AC loads.
When there is no solar, the AIO takes DC power from the battery bank and uses it to power AC loads,
When there is no solar and battery drops below a threshold value, the AIO takes Utility power and passes it through to power loads, plus converts to DC to charge the battery bank.
Click to expand...
so thats essentially all i need. besides wires etc.
 
OffGridForGood said:
A/C and pool pumps are power hogs, other items to consider in your system are Elect HWT, hot tub, Elect clothes Dryer, Stove/Range etc. Your monthly electrical utility bill will tell you past consumption monthly averages, but doesn't tell you the peak electrical output you may need.
A typical home has a 200A 240v service = 48kW peak available, ie more than 4x the 11kW output Inverter. You will need to consider max output for your situation and make decisions about powering some loads from the utility or the inverter or both.
Go to PVwatts online and plug in your location and 7.5kW PV and the calculator will tell you the average monthly solar you can expect* - be aware PVWatts will over-estimate if you have shading or obstructions. Take the monthly values and divide by 30 for daily average values.
I wish I could buy new 550W panels here for 0.25/W (USD) delivered, living out in the sticks has down consequences.
Click to expand...
water heater is propane, main stove/oven is propane but i may upgrade to induction in the future. I do have a hot tub. The pool pump is 12amps max. maybe 6 depending which size i end up needing and it wont run full speed. Dryer unfotunately is electric. I do use some wood working tools too but not super often.

at 14Kw i'm doubling what the solar companies have told me i need to be self sufficient.

I will remain connected to the grid, if my amp draw exceeds the 11kw output would it just snag some power from the grid?

curious why you went with 7.5kW PV if i have 14kw worth of panels?
 
so the local solar installer company told me this:

132 % Consumption Offset
8.100 kW Total Solar Power
20 x 405 Watt Panels (Q.PEAK DUO BLK ML-G10 405)
13,517 kWh per year

the calculator for 14Kw told me:
22,036 kWh/Year
1713571999820.png
 
ahreno said:
curious why you went with 7.5kW PV if i have 14kw worth of panels?
Click to expand...
Because you noted:
ahreno said:
ive had a few quotes from solar companies, they all come up with about a 7.5kw system for my needs
Click to expand...
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this

and to use as a base starting point with PV watts, to see what the calculator indicates this much solar PV would bring in for your area, just as a starting point
 
OffGridForGood said:
Because you noted:

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this

and to use as a base starting point with PV watts, to see what the calculator indicates this much solar PV would bring in for your area, just as a starting point
Click to expand...
ah, gotcha. it's a little hard to go off my past power bills. i used to grow weed so my usage was spiked for drying and dehumidifiers etc. we came to the 7.5-8.x by using my last few months. (with hot tub without cannabis, primary heat is wood fireplace and propane infloor)

i figure if i'm close to doubling their estimate i should be fairly good. i dont really plan to eliminate power comapny alltogether though it'd be a nice bonus.
 
ahreno said:
so the local solar installer company told me this:

132 % Consumption Offset
8.100 kW Total Solar Power
20 x 405 Watt Panels (Q.PEAK DUO BLK ML-G10 405)
13,517 kWh per year

the calculator for 14Kw told me:
22,036 kWh/Year
View attachment 210365
Click to expand...
Excellent starting point,
now let's compare to your utility bill information - ie how many kWh per month do you typically use, and how much does it vary with seasons?

Again this is just for discussion, you don't have to design a system to run the entire home, but you do want to design a system that will run what you intend to have on solar, or plan a way to address seasonal solar variation.
 
There are some inverters that will combine utility and battery/solar to run bigger loads than the solar/battery can handle on their own. This is called load shaving, and is not that common of a feature (yet) but some equipment can do this, and it seems this is becoming more commonly available on high end equipment. Read over the Fronius manual and check for this feature.
Without load shaving, typical inverters will drop out of solar/battery and use utility pass through to supply high loads or low battery/solar condition.
 
ahreno said:
Not sure what else i need for a grid tie / battery backup system.
Click to expand...
From your first post - "grid tie battery back up"
When we (on the DIY Solar forum) talk about "Grid tie" we mean feeding power into the grid from solar.
If you actually mean, having utility available for loads, but NOT feeding into the grid, then we call this off grid, with utiltiy available. ie for big loads or to charge battery off-peak during winter or poor solar periods.

ahreno said:
i dont really plan to eliminate power comapny alltogether though it'd be a nice bonus.
Click to expand...
This ^^^ is from your more recent post #14 and I believe this is what you likely meant back at post #1, but you were not familiar with the subtieties of the jargon we use to describe the relationship with the grid.
True Grid-Tied systems require an agreement with the local utility to provide permission to feed power into their grid.
Off-grid, (including utility power use by you, but never back-feeding) is less restrictive and likely doesn't require any permissions from the utility, only following electrical code and inspections.
 
OffGridForGood said:
Excellent starting point,
now let's compare to your utility bill information - ie how many kWh per month do you typically use, and how much does it vary with seasons?

Again this is just for discussion, you don't have to design a system to run the entire home, but you do want to design a system that will run what you intend to have on solar, or plan a way to address seasonal solar variation.
Click to expand...
it's hard to know for sure because of the change of professions. my power usage was quite high previously. the solar installer came up with these numbers to go off
132% solar offset
13,517 kWh per year

so i'd assume 13517 is 132% over what they figured.

My last few months of usage. I really dont know what uses so much energy. New real efficient home, all LED, propane stove, water heater. wood and propane heat source. all i can think is dishwasher and dryer (i have two kids so lots of laundry).

March - 1048Kw
Feb - 1063kw
Jan - 1208 kw (prior to probably this usage is spike from cannabis)
Dec - 1294 kw
Nov - 1222 kw
OCT - 1531kw
1713573887889.png1713573753789.png
1713573768929.png
1713573783684.png
1713573798114.png
1713573811719.png
 
OffGridForGood said:
From your first post - "grid tie battery back up"
When we (on the DIY Solar forum) talk about "Grid tie" we mean feeding power into the grid from solar.
If you actually mean, having utility available for loads, but NOT feeding into the grid, then we call this off grid, with utiltiy available. ie for big loads or to charge battery off-peak during winter or poor solar periods.


This ^^^ is from your more recent post #14 and I believe this is what you likely meant back at post #1, but you were not familiar with the subtieties of the jargon we use to describe the relationship with the grid.
True Grid-Tied systems require an agreement with the local utility to provide permission to feed power into their grid.
Off-grid, (including utility power use by you, but never back-feeding) is less restrictive and likely doesn't require any permissions from the utility, only following electrical code and inspections.
Click to expand...

i guess i didn't think that far ahead. i'd like to sell back to the power company but i dont know of the extra hoops to jump through. Honestly, this has kind of been a long strange trip. A buddy referred me to a company to get two free tesla power walls installed through power company (basically they jack the install prices up and pocket the rebate) but whatever i dont care, free to me.

then i had them quote me a solar setup, then i got a couple others to compare it to. They were all like $50k-75k. So i looked into DIY cause i'm confident doing it all except tying it to the grid. and now my out of pocket price is looking at like $6k + ground mount setup and permits... which is affordable to get rid of this fucking power bill thats $300+ a months
 
Understood,
In California the members talk quite a bit about NEM2 and NEM3 which are the terms under which they sell back to the utility - not sure if these are State-wide or just in SoCal area, but I know you need to check, because they All say NEM3 (current program after April 2024) Sucks. ie they indicate the sell prices are so low it wouldn't pay for the bother selling back. I suggest you look into this aspect early, because you may need completely different set up to meet a grid-tied sell back agreement. The guys talk about a list for California grid-tied inverters and equipment. The companies that were pricing your turn-key set up likely are well aware of what equipment meets the requirements.

I have a similar situation in my area, where the power costs are already quite low, so what they would pay me for selling kWh back is also too low, and the restrictions and equipment requirement they would impose on me, (and right to access the property) are too high, which is why I am off grid. But what suits me doesn't mean it would suit your situation.
 
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