Win a copy of The Ethical Meat Handbook this week in the Food Choices forum!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources the cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • r ranson
  • Nicole Alderman
  • Anne Miller
  • Pearl Sutton
  • James Freyr
  • Jocelyn Campbell
stewards:
  • Joylynn Hardesty
  • paul wheaton
  • Burra Maluca
garden masters:
  • Steve Thorn
  • Greg Martin
gardeners:
  • Jay Angler
  • Carla Burke
  • thomas rubino

Asking for feedback on my system

 
Posts: 49
Location: Corinth, KY
1
forest garden fungi homestead
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hello! I am setting up a solar panel system on my property but I would like to get some feedback on my system. I have 4-100 watt panels=400 watts. From the solar panel to the charge controller (20 amp charge controller-that I still have to buy) is 10 gauge wire that is buried in a conduit. The panels will be on a mount facing south. From the charge controller to the batteries I"m unsure what gauge of wire I need. I have 2-12 volt marine deep cycle batteries wired in parallel. The wire that is connecting them is an 8 gauge. From the batteries to the 1000 inverter is also an eight gauge wire. From the inverter to the breaker box is the wire that came with the inverter. (I'm not sure of the size). I have a grounding rod with is connected to the breaker box.  

My questions:

1. What size of wire do I need from the charge controller to the batteries?
2. Is an 8 gauge ok to use even though i have a 10 gauge from panels to charge controller?
3. The pictures below show how my breaker box is set up with a jumper wire from one side of breakers to the other side. (one side is lights-other side is outlets). Any other suggestions to get the positive wire from the inverter to both sides of the breaker box?
4. Do you see anything wrong with my system.
5.  What type of charge controller do I need? (is 20 AMP ok)

I'm only using solar for lights and charging things and the igniter on tankless water heater and clock on stove.

I plan on adding more solar panels as time and money comes.  

Thanks in advance!!
10-gauge-wire.jpg
[Thumbnail for 10-gauge-wire.jpg]
batteries-12-V-Marine-Deep-Cycle.jpg
[Thumbnail for batteries-12-V-Marine-Deep-Cycle.jpg]
batteries-in-box.jpg
[Thumbnail for batteries-in-box.jpg]
breaker-box-with-cords-inside.jpg
[Thumbnail for breaker-box-with-cords-inside.jpg]
breaker-box-with-inverter-and-cords.jpg
[Thumbnail for breaker-box-with-inverter-and-cords.jpg]
Breaker-box-with-inverter.jpg
[Thumbnail for Breaker-box-with-inverter.jpg]
breaker-box-with-jumper.jpg
[Thumbnail for breaker-box-with-jumper.jpg]
Breaker-box.jpg
[Thumbnail for Breaker-box.jpg]
conduit-into-barn.jpg
[Thumbnail for conduit-into-barn.jpg]
Conduit.jpg
[Thumbnail for Conduit.jpg]
ground-rod.jpg
[Thumbnail for ground-rod.jpg]
interverter-with-cords.jpg
[Thumbnail for interverter-with-cords.jpg]
Inverter.jpg
[Thumbnail for Inverter.jpg]
 
Diane Maldonado
Posts: 49
Location: Corinth, KY
1
forest garden fungi homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Sorry for the pictures. I thought I had changed them to look normal but I'm working from home and I'm still getting used to the different technology on this laptop.
 
pollinator
Posts: 2720
Location: Massachusetts, Zone:6/7, AHS:4, Rainfall:48in even Soil:SandyLoam pH6 Flat
215
forest garden solar
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The wires are fine for your current setup. The smaller the wire gauge the more amps it can carry in the future.
14 gauge = 15A, 12 gauge = 20A, 10 gauge = 30A, 8 gauge = 40A, 6 gauge = 55A

Inverter
1000W = 24V x 40A, (8 gauge wire)

Charge Controller
20A means 480W of panel aka 24V x 20A (10 gauge or even 12 gauge)

Solar Panel
400W is already installed.
Your charge controller couldn't handle 600W aka 6 panels, so there is no room for growth.
I also wouldn't recommend installing 5 panels for 500W but you might be able to get away with it for a while (500W vs 480W)

Battery
How much AH does your batteries have?
Lets assume it is 20AH+ each for 24V x 20A = 480W
You would have to run your battery at 2C (twice it capacity) to get 1000W. In reality you want to run your battery at quarter capacity (0.25C). But its okay it will still work, at some point you want to get 24V and 160AH.

I would recommend getting a 50A charge controller
 
S Bengi
pollinator
Posts: 2720
Location: Massachusetts, Zone:6/7, AHS:4, Rainfall:48in even Soil:SandyLoam pH6 Flat
215
forest garden solar
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
You never want to discharge your 480Wh battery more than 50%, but even at a 80% discharge you can only get 380Wh out of it.

LED light = 10W/each, amount = 10, avg runtime each = 2hrs = 10x10x2=200Wh
Thankless Water Heater = 2W, runtime = 16hrs of no sun 32Wh
Clock = ??, lets go with 50Wh per day
Charging phones/etc = 50Wh per day
 
pollinator
Posts: 254
Location: Nomadic
23
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi,
I agree. I would buy a bigger than 20 amp charge controller if I was planning to add more solar panels later. And go with a 24 volt system if you plan to grow the system a little. Go with a 48 volt system if you plan on growing it a lot.
If the 12 volt batteries are wired in parallel as you stated in your OP then you have a 12 volt system not a 24 volt system. If so that inverter will draw 80 amps give or take from the batteries through those small 8 guage wires. Also those DC wires are rather long between the inverter and the batteries. Even if your loads are currently very small it really is best to install correct size DC wire for the inverter. I think 4 guage would be more appropriate. And not so long. Raising the batteries off the ground on a tall platform would shorten the wires.
 
pollinator
Posts: 362
Location: North central Ontario
42
kids dog books chicken earthworks cooking solar wood heat woodworking homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I would suggest a thicker wire from batteries to the inverter. Technically is should be 4 or 2 gauge... at least a multi strand 6 gauge to reduce losses through the wire. Where abouts are you? If you get cloudy periods of the year I would suggest you get an mppt charger so that you can run 2 strings of 2 panels each and get some charging on those cloudy days. As voiced above get more charger then you need right now. An mppt charger will also let you change the array without having to rewire to the batteries...
Cheers,  David
 
Goodbye moon men. Hello tiny ad:
177 hours of video: the 2017 Permaculture Design Course and Appropriate Technology Course
https://permies.com/wiki/65386/hours-video-Permaculture-Design-Technology
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!