Thoughts on this setup...

michael.2021

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Oct 27, 2021
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Growatt 24V 3kw SPF 3000TL LVM Inverter (1x)
EG4 24V LiFePo4 Battery (1x)
EG4 24V Battery Charger (1x)
Rich Solar 200W 12V Poly Panels (6x)

Above is the best setup I could find in 20 hours of research around the internet. Pretend I know nothing about this subject matter as that happens to be the case here. I'm very space limited in where I can gather sunlight (in an apartment with balcony that faces sun about 8 hours of the day) and I can only use 2 panels at any time. Just looking to power a 1kw space heater in winter months if grid goes down and use 240w gaming laptop simultaneously for an example of my hardest load, and recharging high-intensity flashlights for an example of an easier load...

Any issues with a setup like this?
 

sunshine_eggo

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Oct 26, 2021
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Location
USA
Growatt 24V 3kw SPF 3000TL LVM Inverter (1x)
EG4 24V LiFePo4 Battery (1x)
EG4 24V Battery Charger (1x)
Rich Solar 200W 12V Poly Panels (6x)

Above is the best setup I could find in 20 hours of research around the internet. Pretend I know nothing about this subject matter as that happens to be the case here. I'm very space limited in where I can gather sunlight (in an apartment with balcony that faces sun about 8 hours of the day) and I can only use 2 panels at any time. Just looking to power a 1kw space heater in winter months if grid goes down and use 240w gaming laptop simultaneously for an example of my hardest load, and recharging high-intensity flashlights for an example of an easier load...

Any issues with a setup like this?

Battery is 5kWh
400W of panels is only going to pull in 2kWh/day if you get great sun.

You can run your space heater for 2 hours average per day indefinitely.

The battery will power it for 5 hours.
 

rmaddy

Full-time Solar-powered Trailer Life
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Nov 16, 2019
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1,238
Why 6 panels if you can only use 2?

Battery is 5.12kWh. Figure 80% usage. That's 4096Wh usable. 1000W heater + 240W computer = 1240W. That battery will power both for a total of 3 hours 18 minutes. But the inverter is only 90% efficient so that's 3 hours. This assumes the heater is running at 1000W constantly. It will probably cycle on and off once at temperature so you might get closer to 4 hours before the battery needs to be recharged.

Two 200W panels in the winter (on a sunny day) might give you 400W x 4 hours x 0.8 (or less if the panels aren't perfectly aligned with the sun) which is 1280Wh of charging. You might get more out of the panels if you can keep them pointed directly at the sun the entire 8 hours but you won't get a full 400W for 8 hours, not in the winter.

Your heater and computer need the same load so while the solar panels are getting great sun for those 4 hours you can power the heater and computer without using any battery. The battery will give you another 4 hours of runtime. But at that point there is no sun and no way to recharge the batteries.

If you do run the battery down all of the way it will take a bit over 3 full sunny days to recharge the battery with the two panels. And during that time you can't use the heater or computer.

Maybe get two 400W panels instead of 6 200W panels. Not sure your space will fit two 400W panels.

A lot depends on how long your power will be out and how sunny it is while the power is out. If the power is out for only a few hours then you could run off of the battery and forget using solar. Recharge the battery when the power comes back on. If the power is out for a full day then maybe use 2 or 3 batteries and no solar. Again, recharge when the power comes back on.

The problem is your loads (heater + computer) use more than the little bit of solar can keep up with if needed more than a few hours.
 

michael.2021

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Oct 27, 2021
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Great thoughts, thanks I appreciate the really great info. It sounds like I better look into how to safely/securely strap 2 more panels against the balcony's outside wall and the outside of the sliding door pane...wanted to avoid potential "jankiness" but yeah good call...
 

rmaddy

Full-time Solar-powered Trailer Life
Joined
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Messages
1,238
Keep in mind that if you are strapping panels to walls and sliding doors then they are not going to get the most sun possible due to the angles. So more reason for more and/or bigger panels.
 

michael.2021

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Oct 27, 2021
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Hmmmm very true...ok I'll research a bit more to see what else I can come up with given my space constraints...
 

michael.2021

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Oct 27, 2021
Messages
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Ok, I've read up more on the benefits of 48V (more scalable later and more efficient power delivery if I understand correctly) so in collaboration with some last minute conversations with some solar companies, I switched out most of my components to the below:

Growatt 48V 3kw SPF 3000TL LVM Inverter (still went with 3kw variant vs 5kw to more easily get over the total VOC I needed to power the inverter with fewer panels)
DC Disconnect Isolator Switch (for times when I need to unplug the panels during the day when under load to prevent possible shock)
EG4 48V LiFePo4 Battery
4x Rich Solar 200W 24V Monocrystalline Panels
10 Gauge Cables (from panels to DC disconnect switch)
2 Gauge Cable (need to buy from Home Depot or wherever for inverter to battery)
Flexible Branch Pairs (to connect the 2 series of 2 panels together to equal 4 panels in use because the inverter only has one PV connection and I'd exceed allowable amps if all 4 were in the same series)

I'm being told that I should get an electrician over to advise on how to ground the inverter in case of lightning strike...which will be hard to do since I'm in an apartment...I can't tap into a ground that's somewhere outside the building because I don't own this place of course, and I can't run my own copper wire to the dirt multiple stories below me because I'm not allowed to "consume" more "space" than is allotted to me by lease (my guess of what the landlord's legal standpoint would be I mean...not like I'm going to go ask the Office Manager to advise on behalf of the corporation that owns this place this year). I'll never plug into the grid and won't ever be "selling back" to the power company. Should I bother with ground on this "closed" system?

I'm worried that I should also get some fuses throughout my system for peace of mind but have no idea what the eff I'm doing...should I or shouldn't I?

P.S. If anyone's looking, Rich Solar just released new 335W 24V panels yesterday...I almost went with those but changed my mind because they are required to go by freight so you'd have to order a minimum of 8 to have them offer the free shipping.
 
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