need some input on what i 'think' is a good starting point.

[ncc74656]

northern MN. house is n/nw facing. small roof area facing south and arcetecture creates shadows one way or the other for about 1/4 of the day on the "best" surface area. i need grid tie, feedback, battery.

760kwh on my BIG months. 25 or so a day. 1.04kwh a day. worst case. 3.8 average solar intensity with 1.2 in winter.

550w panels give 480@80%, 8 of those vs 10 of those? OR go wtih 450W panels and do 10 or 12? idk

DC string low frequency inverter. thinking of maybe two banks of panels in series parallel from garage to house and then one more bank on the house in series. bring that dc voltage up for the longer run to the inverter.

i have lots of 220v stuff - air compressor @ 30A, welder @ 50A. 110V highest power is computer/stereo at 28A. house and garage are both 100A service.

inverter: https://sungoldpower.com/collection...-hybrid-solar-inverter-split-phase-120-240vac

panels: https://sungoldpower.com/collection...products/550-watt-monocrystalline-solar-panel

battery: https://sungoldpower.com/collection...-server-rack-lifepo4-lithium-battery-sg48100p

im having a hard time finding cost savings on the battery. the panels i can find used but then they are lower wattage. so not sure there. and the inverter... thats the best price i can find anywhere for hwat i need.

id like to keep budget as low as possible for ROI. thinking of inverter and panels first and maybe battery later.

thoughts? thanks.

 

[rodrick]

You may what to look at watts 24/7 they sell growatt and mpp which are all made by voltronic including sungold power and many others, for $1099 for the 6048 and signature solar has the 6548 for $910 each in their savings shack and watts has them for $1999 a pair and they are ul listed sungolds are not

 

[SamDeleted]

If you're looking to save costs on the battery, consider AGM / gel batteries

Particularly motive power/ traction batteries, they have a lot thicker lead plates. There's fantastic deals around on used/like new condition batteries, good long life span, (not quite as good as lititum!) But if you shop around carefully can work out a fraction of the cost of LiFePo4

Sonnenschein Gel Cell Batteries

That server rack you posted is only 5kwh~ and $1500 , I've just bought 30kwh (15kwh useable ) of gel tractions for £1350

 

[SamDeleted]

That server rack you posted is only 5kwh~ and $1500 , I've just bought 30kwh (15kwh useable ) of gel tractions for £1350

Now lifepo4 have a longer lifespan , 3000-5000 full cycles .....if all goes well


Where as the tractions are rated for 900-1000~ cycles, but that is for cycles all the way down to 10%soc (state of charge) , if you only take them down to 50% SOC they last much much longer

 

[ncc74656]

Now lifepo4 have a longer lifespan , 3000-5000 full cycles .....if all goes well


Where as the tractions are rated for 900-1000~ cycles, but that is for cycles all the way down to 10%soc (state of charge) , if you only take them down to 50% SOC they last much much longer

thats fair. ill prob do the battery second anyway. i want the panels and inverter up and running first. then id use the batteries in the winter. so... ill bet they get heavy use given our climate here

 

[SamDeleted]

thats fair. ill prob do the battery second anyway. i want the panels and inverter up and running first. then id use the batteries in the winter. so... ill bet they get heavy use given our climate here

You might want a small battery bank just to keep the inverter happy , even if you're only running in solar hours

4 car batteries work well for 48v

 

[ncc74656]

You might want a small battery bank just to keep the inverter happy , even if you're only running in solar hours

4 car batteries work well for 48v

i can get some AGM from work. we will see. its complicated because to qualify for rebates i need everything to be new. i cant use used and it all needs 25 year warranties on it for panels and i think 10 or 15 for battery and inverter? then i need the power company to approve the plans, their apraiser to sign off, the electrical inspector to sign off, and then i need an energy audit before and after. IF i produce more than 120% of what i use the year after i install i get fined for all the power i generate back to the grid over that 120% so i need to monitor that to make sure im not going over. which is why im looking at these smart inverters and batteries.

 

[SamDeleted]

i can get some AGM from work. we will see. its complicated because to qualify for rebates i need everything to be new. i cant use used and it all needs 25 year warranties on it for panels and i think 10 or 15 for battery and inverter? then i need the power company to approve the plans, their apraiser to sign off, the electrical inspector to sign off, and then i need an energy audit before and after. IF i produce more than 120% of what i use the year after i install i get fined for all the power i generate back to the grid over that 120% so i need to monitor that to make sure im not going over. which is why im looking at these smart inverters and batteries.

Oh I see , does it all have to be bought in one go to get your rebate ? How much is it 50%?

I guess lithiums not so bad when you're only pay half !

 

[DIYrich]

You can DIY a 14kWh battery for about $3k. I just got the major stuff from 18650battery, and the rest from your favorite supplier (shunt, fuse, wire, etc).