New to the forum, and it looks like I've got a lot to learn. First, Help me start up my kit?

Chachoriffic

Greetings,

I'm going to give off grid living a shot. So I've bought myself a 12v solar kit off of eBay. http://www.ebay.com/itm/Solar-Cynergy-320-Watt-Kit-TWO-12-Volt-Mono-Solar-Panels-160-W-Watt-PV-Panels-/351354234116?hash=item51ce582504:g:3SwAAOSwNSxVFJQV

I'll have it in my hot little hands shortly if any details need to be more carefully looked over.

I have a few concerns off the bat: 

-Wire sizes (I don't want to cheap out on proper wires/connections)
-Fuse and switch types and locations
-batteries. More specifically 2x 6v golf cart batteries, or 4x 6v? Personally I'd like to go with 4, bit I have no clue if that is overkill, or just a prudent measure to support a healthy system?)
-generator? Do I need one? I would like to use a power tool once in awhile. I could go lithium cordless. Back up power, charging power? Was thinking about the el cheapo 2500 inverterless honda generator 
Suitable, reliable, efficient Inverter? I was looking at the xantrex prowatt 2000

Peak times will be in the evenings, and in the dark. I'll be running and charging my laptop (could charge it in the day time too), charging my phone, headlamp battery packs, AA Batteries, car stereo will be on a fair bit, and maybe a bar fridge....and maybe maybe maybe a small efficient heater if needed or if there is such a thing. Wood stove is very likely an option. 

Any input is much appreciated. I'm sort of in fly by the seat of my pants mode right now, and will have much more time to learn the lingo and more for myself in about a month or so when I have the basics covered.

DConlyGuy

1st thing you need to do is look at your amp or watt load of your stuff and see if you really need a 2k inverter. at 12 volts and if you are really using 2k of inverter power you will drain the 2 golf cart battery's in and hour

mike95490

Not going to get the bar fridge, that consumes too much power.   Sorry,
Same with heater, you are going to get a simple wood stove, 
 Beware of pellet stoves with a fans and a 300W glow coil to keep the burner hot.
Look to 6V golf cart batteries, 2 will make a nice beginner battery bank. 
I didn't see any fuses on the kit, you need a fuse to protect the wires,  Ask more about that.

Chachoriffic

As I know nothing about this rig at all I figured I'd take some pictures

Do I absolutely need a fuse from the panels to the charge controller? The charge controller claims to have four types of protections built in.  


Looks like I'm supposed to splice this cable for the charge controller.

Also, is there any absolute no no's when mounting these panels? They came with Z brackets I think they're called? I'm going to mount them on the south facing wall of my shed, probably with 2x4s positioned between the studs in the appropriate places.  I'm more concerned with the angle of the panels. I was thinking about using 4x4 blocks to customize my angles 

BB.

Solar panels need to point to the sun... And depending on when you need to generate the most power, you can have a fixed (or adjustable) tilt. Nominally, for the most power (all 4 seasons) added together, you would tilt to your Latitude. If you are at 46 degrees North, you would tilt the panel to 46 degrees from horizontal. If you needed more power in sun, tilt to ~ 46-15=31 degrees. For winter, +15 degrees. If you have a lot of snow and want to keep the battery at float during winter, set the panel near vertical:

http://www.solarelectricityhandbook.com/solar-irradiance.html

Brampton
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 46° angle from Vertical:
(For best year-round performance)

Jan	Feb	Mar	Apr	May	Jun
2.71	3.50	4.04	4.50	4.75	5.12
Jul	Aug	Sep	Oct	Nov	Dec
5.24	4.98	4.58	3.68	2.47	2.24

Depending on the size/configuration of your solar array--You only need a fuse per panel (or series string of panels) if you have 3 more more panel (strings) in parallel. Otherwise, you do not need any protection on the solar panel side (assuming correctly sized cables, etc.).

What is the the size/configuration of the solar array (number of panels, Vmp and Imp of panels, etc.)? More or less, you want 5% to 13% rate of charge (5% will work for a weekend/summer cabin with light loads). And 10%+ for a full time off grid one (and 10%+ is best usually for battery health).

For example, if you have 4x 6 volts @ 200 AH batteries in 2x series by 2x parallel--That give you a 400 AH @ 12 volt battery bank:

• 400 AH * 14.5 volts charging * 1/0.77 panel+controller derating * 0.05 rate of charge = 377 Watt array minimum
  
• 400 AH * 14.5 volts charging * 1/0.77 panel+controller derating * 0.10 rate of charge = 753 Watt array nominal
  
• 400 AH * 14.5 volts charging * 1/0.77 panel+controller derating * 0.13 rate of charge = 979 Watt array "cost effective" maximum

And then the output of the system (~45 degrees) for Brampton ON, toss the bottom 3 months (assuming generator support and/or closed up for season):

• 753 Watt array (nominal) * 0.52 off grid AC system eff * 3.50 hours of sun (Feb break even) = 1,370 Watt*Hours (Feb long term daily average)

If you have 4x golf cart batteries, a 2x 160 Watt array is pretty small (and at 320 Watts, really below 5% rate of charge).

Regarding an AC inverter, for a 400 AH battery bank (flooded cell golf cart batteries, lead acid type), realistically, a 1,000 Watt inverter maximum would be recommended... Depending on your loads, a smaller AC inverter makes more sense (charging laptop, cell phones, running some LED lighting at night, etc.). Use the genset for power tools (skill saw, etc.).

Wire size/breakers/fuses are usually placed on the positive battery bus for each wire that leaves to the load/charging source. The battery bank is the source of high current. Wiring and breakers/fuses should be sized for 1.25x expected continuous current. Say you have a 1,000 Watt AC inverter:

• 1,000 Watts * 1/0.85 inverter eff * 1/10.5 battery cutoff voltage * 1.25 NEC derating = 140 Amp minimum AC wiring+breaker (round up to next standard size)

For mounting the solar panel--Best is to have a sturdy frame (or rails) to mount the panel on. Note that solar panels do not take "twisting" of the frame well (i.e., standoff for panel tilt on one side only)--These are only single weight tempered "window glass"... If you have snow/high winds, the framework needs to be able to support those loads.

-Bill

Chachoriffic

Thanks. I'll digest some of this for a little while. I'll probably go with two golf cart batteries.

I should probably build a 2x4 frame for each panel, and then secure that frame to the wall. I'm probably going to go vertical, or near vertical. The sun is pretty much gone once it passes my south wall. When the sun comes up and is in sight it's pretty much hitting the wall all day, for 6 hours. I'm in NW Ontario near the US border at grand portage

BB.

Up towards the poles, panel angle can matter a lot... Here is what it can look like with a vertical panel (closest to you?). Vertical can cost you 1/2 of your summer production:
http://www.solarelectricityhandbook.com/solar-irradiance.html

Duluth
Average Solar Insolation figures

Measured in kWh/m2/day onto a vertical surface:

Jan	Feb	Mar	Apr	May	Jun
2.40	3.33	3.44	3.19	2.93	2.82
Jul	Aug	Sep	Oct	Nov	Dec
2.98	3.10	3.05	2.84	2.41	2.11

Duluth
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 43° angle from Vertical:
(For best year-round performance)

Jan	Feb	Mar	Apr	May	Jun
2.54	3.79	4.46	4.85	5.03	5.03
Jul	Aug	Sep	Oct	Nov	Dec
5.29	4.99	4.20	3.38	2.59	2.18

Duluth
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 58° angle from Vertical:
(Optimal summer settings)

Jan	Feb	Mar	Apr	May	Jun
2.32	3.56	4.40	5.02	5.41	5.53
Jul	Aug	Sep	Oct	Nov	Dec
5.75	5.26	4.22	3.23	2.39	1.98

Many folks make the wall mount something that can be adjusted a couple times a season for optimal harvest.

-Bill

Chachoriffic

I'm concerned with winter only, for now. This is great information. Some discrepancies beg questioning to the sample size.

BB.

Sample size of the solar data? Typically 20 years or more, from a few decades ago. Here are some details:

http://pvwatts.nrel.gov/pvwatts.php

What they do is pick a Day (or a Month) of measured that is representative of that 20 year or so of measured data--So the numbers are "real" and include clouds/storms/atmospheric dust+humidity/etc.

1 Month numbers can vary from one year to the next by 5-10% or more (depends on local weather patterns).

-Bill

Chachoriffic

So where do I go for the absolute most dummies guide to setting my kit up? I don't even know what series or parallel is. I don't have a clue how to connect which wire's to the battery posts(?), and I desperately need to set this up soon so I can focus on actual survival management

Raj174

This Youtube video covers the basics.

https://www.youtube.com/watch?v=eTvXx9tBkuU&list=PLoHd6hGDqS06g0umrn4XO0Wk9JyZcTfMa

Rick

BB.

Here are some recommended books:

http://forum.solar-electric.com/discussion/comment/99323#Comment_99323

Also, member 2manytoyz has a nice history of his installations (from early projects to a complete upgrade for his latest system)--Most everything was DIY (do it yourself). Scroll about 1/2 way down his website:

http://www.2manytoyz.com/

-Bill

Chachoriffic

To add to my astounding ignorance I just purchased a samlex 300w inverter and a samlex solar 3 stage battery charger. I plug the charger in to my generator, right?

westbranch

Is it a  charger or Charge Controller?  Model will greatly help...

As to the 2x4 rack for the panels , use a 30/60/90* frame like this for winter...

there is a small lip on the bottom and top rails (2x4) and 2 lips on the center one cut out with a table saw so as NOT to cast a shadow on the PV cells, mount bottom PV first and add as you go up.  It is reallllly windy in fall and winter hence the 4x5 for weight  to prevent tip  over

BB.

Can you post links to the two products?

A "solar 3 state battery charger" sounds like it would not plug into a genset.

Samlex does make both AC and Solar battery chargers.

-Bill

Chachoriffic

Samlex Solar SEC-1215UL SEC-UL Series 12V Battery Charger 

Samlex America SA300112 300W Pure Sine Wave Inverter

(Crosses fingers)

Thanks westbranch, this is exactly the way I may go. I'd like a 10-15 foot tower/pole, but I'm not sure it's in the budget atm

Edit: I went with 300w because I've been getting 70℅ of my needs off a 175w pos hardware store inverter plugged in to a van

Chachoriffic

Got my inverter and charger today. 

It unexpectedly came with 10awg wire and connectors. I've read a number of people using 6awg wire for this and their inverters. Should I? And how short can I make the wires going to the batteries? As short as possible? Equal length black and red? Is there some sort of oscillating frequency to wire length optimization to follow? Fuse, and switch on the red?

BB.

Check the manual... But some basic engineering math:

• 300 watts * 1/0.85 AC inverter eff * 1/10.5 volts batt cutoff = ~33.6 amps

For North America, we use a x1.25 NEC derating factors for continuous current flow (this is conservative, but definitely recommended if you don't want warm wires and occasional breaker/fuse trips):

• 33.6 amps * 1.25 NEC derating = 42 Amp minimum wiring + breaker/fuse

Now, looking at the Marine ratings for wiring (not conservative):
http://www.boatus.com/boattech/articles/choosing-cables-and-terminals.asp

• 10 AWG is rated for 51 to 60 amps

Using NEC (national electric code)--Much more conservative (wire in conduit, taking different insulation/temperature options into account):
https://lugsdirect.com/WireCurrentAmpacitiesNEC-Table-301-16.htm

• 8 AWG is good for ~40-55 amps

Now, you need to look at wire/cable length for voltage drop--Assuming 0.5 volts maximum drop:
http://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=3.277&voltage=12&phase=dc&noofconductor=1&distance=7&distanceunit=feet&amperes=33.6&x=42&y=10

• 10 AWG for 7 feet (one way run):
• Voltage drop: 0.47
  Voltage drop percentage: 3.92%
  Voltage at the end: 11.53

If you do not put the 10 AWG in conduit, and keep it to less than 7 feet--It will work.

HOWEVER, folks are not used to working with high continuous current flow--I would pick the more conservative wiring options when you have the choice. In your case--you have pre-made cables and connectors--I would not be against a 3 foot cable run and using the existing 10 AWG cables--And see how it works (and check the wiring temperature after running maximum loads for 10-20 minutes--If everything is cool--Should be OK.

-Bill

Chachoriffic

Ok so I'll keep the wire for now. It's about 2ft tops per wire. 

So, I'm going to connect my two solar panels together using the provided y connecters, then I'm going to run them to the charge controller with the included 10awg pv wire.  

From the charge controller to the batteries. What size of wire is ideal? Can I use leftover 10awg pv wire? 

I'm also curious about the connections to the battery posts. If I have wire from the charge controller, wire from the inverter, and wire for the series/parallel connections....how do I connect them all without cramming the posts?

And If I am allowed to skip the fuse between the panels and the controller, where then should I absolutely put fuses and switches? What am I looking for at my hardware store? A fuse holder or some sort?

I appreciate the math and formulas, and they are slowly permeating in to my consciousness. But right now I need to get this done, and then fine tune details, monitor etc. Afterwards. Provided it works to begin with lol

Edit:  I forgot about the car stereo. I'll have a simple car stereo connected directly to the batteries I suppose(?). Those usually have 5amp fuses connected to them don't they?

BB.

Chachoriffic said:

So, I'm going to connect my two solar panels together using the provided y connectors, then I'm going to run them to the charge controller with the included 10awg pv wire.  

From the charge controller to the batteries. What size of wire is ideal? Can I use leftover 10awg pv wire?

That same voltage drop calculator will work. For a 12 volt battery bank, I would suggest 0.05 to 0.10 volts maximum drop (for accurate battery voltage/quickest/best charging).

http://www.calculator.net/voltage-drop-calculator.html

What size array will this be? What charge controller.

I'm also curious about the connections to the battery posts. If I have wire from the charge controller, wire from the inverter, and wire for the series/parallel connections....how do I connect them all without cramming the posts?

Bus bars are common--Or even a long brass bolt with stacked connections can work. A nice thick copper water pipe flattened with drilled holes+bolts works well too. Poster 2manytoyz (1/2 way down his website) has documented his journey... Good place for ideas:

http://www.2manytoyz.com/
https://www.solar-electric.com/catalogsearch/result/?q=bus+bars (our host's bus bars)

And If I am allowed to skip the fuse between the panels and the controller, where then should I absolutely put fuses and switches? What am I looking for at my hardware store? A fuse holder or some sort?

When you have three or more solar panels (or panel strings) in parallel, you should have a fuse/breaker per parallel string connection. Fuses work--Breakers are nice because they protect and are handy switches for debugging.

Many folks will put a switch (or breaker) in the PV input + line--But it is not really necessary--But, again, nice for debugging.

I appreciate the math and formulas, and they are slowly permeating in to my consciousness. But right now I need to get this done, and then fine tune details, monitor etc. Afterwards. Provided it works to begin with lol

You are welcome--You might add a signature on your user ID--Even if it is just your proposed system at this point (panels, charge controller, battery bank info, inverter, etc.)... I really like to look at the system as a whole--And ensure the results are "balanced". It is very easy to get lost in the details (i.e., you change the battery bank, and do not change the number of solar panels to charge the system).

http://forum.solar-electric.com/profile/signature

Edit:  I forgot about the car stereo. I'll have a simple car stereo connected directly to the batteries I suppose(?). Those usually have 5amp fuses connected to them don't they?

Yes--But check the standby current (many older stereos would take a fare amount of current when "off"). Also, many are not that energy efficient (i.e., use a battery powered radio, or cell phone+blue tooth speaker, etc. -- Battery based devices tend to be more energy efficient).

-Bill

Chachoriffic

2x160w 12v mono panels with a 20amp controller. 

littleharbor2

While it may be overkill for your small system positive and negative buss bars are a great way to make your multiple connections, or a positive fuse block and neg. buss bar.

Chachoriffic

I'll see if my local hardware stores carry them.  

Listening to wolves howling.... they're coming for me

littleharbor2

Very cool. Where are you located?

Chachoriffic

Northwestern Ontario near Grand Portage. 

I'm converting a lean-to in to a straw bale shelter for the winter. So this solar kit is vital. I'm just about ready to start piling in the straw, and somewhere along the way I should fit a conduit pipe of some sort

kamchuka

Pics?

softdown

I hope you are made of tough stuff. We are entering the four roughest months for solar production, especially true for northern folks. The batteries will also have a lower output when they are cold.

I would encourage you to try to find a finished place for the winter and prepare your shelter in earnest with improving weather on your side.

Power tools often use 10 to 15 amps with a starting surge that may be three times that much. So the minimum inverter size is approx. 3500 watts with good surge capacity. Just fire up a generator when you need to use a real power tool.

I'd like to see you with double the panel array and double the battery bank....if possible.

Chachoriffic

I'll be fine. Batteries won't be cold, and gen is already being used for power tools. Well see how the two works. I kinda want 4 as well

softdown

What are we missing? According to this, Grand Portage, Ontario is close to Lake Superior.  http://travelingluck.com/North+America/Canada/Ontario/_5964655_Grand+Portage.html

"Northwestern Ontario near Grand Portage."  Typo?

Chachoriffic

A wood stove? I don't know what anyone's missing, sir.

Chachoriffic

Hey westbranch,

Have you had any problems with your stands at all? I'm worried about high winds. Mine will need to be 2-3 feet off the ground, to account for potential snow fall. Also they won't be resting against the cabin.

I was thinking of maybe building an 8ft wide stand, to accommodate two horizontal panels adjacent to each other, and deep enough to hold four total. Perhaps that would be wide and deep and heavy enough to withstand high winds?