Rock2Fox's Solar Power System

[Rock2Fox]

After much waiting, advice collecting, supply gathering, trial and error (much more error than trial) the solar power system is up and running as of 1830 tonight. Big thanks to Trioxin and BenjamminR for keeping me from electrocuting myself and for all the guidance.

Before pic, equipment sitting around not hooked up to anything. On the left is the solar combiner box acting as the disconnect for my solar panels, in the middle/ left is a Xantrex C40 charge controller, next up is a Midnite Solar MiniDC DC breaker acting as my battery bank disconnect. Next is a Xantrex Prosine 1800w (pure sine wave) inverter I scored off of Ebay on the cheap (its refurbished). The batteries are MK/ DEKA AGM batteries w/ a 183 aHr @ 10 hr. capacity. The cable on the far left is a 2 conductor (#10 AWG) 25' output cable.



Box o' cables: intermodule cables (2 conductor #10 AWG) at 2.5', the short thick black ones in the bottom are 12" #2/0 AWG battery cables, and the thin fused cables are the inverter cables (#10 AWG).



The first real work I did was to mount the DC breaker (battery disconnect) to a piece of 2x4 and bolt it to the frame of a modular workbench.



Next up was wiring the breaker to the batteries. Yes, I realize a socket is stuck on the negative grounding lug . . . laugh away.



Next the wires from the breaker to the inverter on the desktop.



I drove this 3/4" solid copper grounding rod about two feet in the ground, then ran a #6 solid copper to the DC breaker to serve as the system ground.



Here are the panels installed. Three 110w Mitsubishi 12v panels wired in parallel, attached to the roof using a UniRac flush mount.



Here is the completely wired system.



Here is a picture of the charge controller, the sun was going down and it was cloudy --- you can see the electrical output even under these circumstances.




Please give your thoughts and comments on this setup.

[kyle]

Awesome! Thanks for sharing.

Do you have any horror stories or advice you can share with those of us who have serious interest in setting us something similar?

How long will they take to pay off, considering material cost and what you'll be saving in utility bills?

[TheFreakinBear]

Awesome! Thanks for sharing.

Do you have any horror stories or advice you can share with those of us who have serious interest in setting us something similar?

How long will they take to pay off, considering material cost and what you'll be saving in utility bills?

+1.

Looks like you did a great job! I would love to do something like this and am interested in material costs as well. Thanks!

[E]

I'm curious what batteries you used. as well as system costs

Congrats man! Do a full test (after its charged up) to see how much it can take and times, and let us know. I've been itching to do something like this forever...

[Trioxin]

Straight up pimp!
Glad to see you decided to put the panels on the roof.
What guage wire are you using from the controller to the batteries? When you get a sunny day, that is going to be pumping some amps. Is it at least 10 guage?? PM me if you wanna talk off the board.
You have elevated yourself above the masses of people who talk about "someday setting up a system". You actually did it. You should be proud.
Keep up the good work man! Thanks for the props too!

[Rock2Fox]

Cost-wise, this project quickly became a money pit. I think there are really two mindsets for doing something like this: (1) to try to do if for the least amount of money, and get the most watts/ amps per dollar, or (2) to build a system that is as safe as possible. I made a sort of hybrid attempt of (1) & (2).

A little background info on the project first. I have a gasoline generator to use in emergencies; so one day I told my wife I was going to fill some 55 gallon drums full of gas to keep on hand to use to provide power. I gave her the choice between having a fairly large quantity of flammable liquid in our garage, or spending some cash on an alternative energy source. Thus the genesis of this system.

I first planned on using marine batteries, but based on my needs and not wanting to have a vented battery box which had a way to get rid of the hydrogen by-product of deep cycle charging I chose to spend more money and get the most "maintenance free" batteries I could. I chose the MK/ DEKA 8G4D (I think that is the model, listed at 183 amp hour @ 10hr. rate) $375/ per batt.

As far as the panels, I chose these based on cost, they were $475 + freight from an internet vendor (Mr. Solar). These prices are not awesome, but I believe you get what you pay for and nothing really screamed "quality" on Ebay.

Cables, were not a cost that I considered before hand. This is definitely an area where you could save money if you wanted too. I hope to expand this system as I get more cash, so I opted to buy larger battery cables (#2/0) that would handle the largest loads. I firmly believe that I could have bought #4/0 AWG from Wal-Mart and been just fine with this setup (but I didn't). So all in all the cables cost about $130 (for 2.5' of #2/0 AWG battery cable between the DC breaker and the batteries; 12" of #2/0 battery for parallel wiring as between the batteries; 2.5' of #10 AWG wire as between the charge controller and the batter; 52" of #10 AWG intermodule cables; 25' of #10 AWG output cable, this is basically the same thing as the intermodule wiring, but in a heavy duty light resistant outer insulation; and lastly a 100ft. 12ga. outdoor extension cord).

The UniRac mount ran about $150; Trioxin made his for free, so I don't know if this was necessary, but b/c I live in a VERY windy part of the US, I didn't figure this was an area to cut costs on. Plus I don't have a bed frame or any welding skills.

The Xantrex C40 controller was about $199, w/ the digital display and battery temperature sensor (used to help the controlling functions be more accurate I suppose) added in (purchased new on Ebay).

The Xantrex Prosine 1800w Inverter was the most questionable of my purchases b/c it had been refurbished. However for $460 I took the gamble. A new unit retails WITHOUT a GFCI (the plug for your extension cord) for around $1100. I paid for the name, and paid for the "pure-sine" wave aspect, which I gather you need to run complicated appliances such as laptops and the like.

The DC breaker was $175 including the 150amp breaker; also something you don't need, but it gets me closer to being up to local electrical code and allows me to disconnect the batteries if I ever need to work on the AC side of the system.

The other DC breaker that works as the panel disconnect, is an OutBack solar combiner box which cost $120. Also not exactly necessary, and I'm also not using it for its intended purposes which was to combine multiple panel arrays into one output. But whatever, it is part of what makes this system just a little more expandable in the future.

So the short answer is I spent a LOT of money, MUCH MORE than I intended, but I think it has staying power and will facilitate future upgrades with ease.

Hope this helps.

[zoom1200]

Very cool thanks for the post.

what are you planning to run off this system?

[Rock2Fox]

A chest type deep freezer and a washing machine. We'll see in the next few days how hot the wires get and if the breakers trip. I'll continue to post with what I am able to run and what-not.

[Rock2Fox]

For kyle's post:

As far as horror stories and advice, I really don't know where to begin. I am pretty good a direction question, direct answer - but I don't know where to begin advising. I also am probably not the best source for sage electrical engineering advice, but I am more than happy to share what I have learned.

Some simple stuff:

1. Don't try to mount the panels on a ground level concrete pad. Shadows will get in the way, and you will throw rocks if you have to mow/ weed-eat near them.

2. Buy extra wire, I ended up having to trim a lot because I mid costly mistakes calculating distances. Or in the alternative, be good at math.

3. This is the worst screw up I did- All of the components and junction boxes have "knock-outs" or holes for conduits of different sizes, 1/2", 3/4" whatever, it is beside the point. The knockouts in the bottoms of the boxes I just used a hammer and a flathead and went to town and popped them right out. But when I tried to do the same on the knockouts on the sides of the boxes I bent the shit out of the side of the boxes of some pretty expensive equipment. It had no functional impact, but was still pretty irritating. The moral is, I don't know how to properly remove side "knockouts", but I do know that I would advise people just to keep it simple and use the ones on the bottom.

4. Size the wires correctly, there are charts and stuff if you Google them for a minute that compare the distance the wire is going to be run with the amount of amperage running through it and tell you which wire to use.

I guess time will tell what other mistakes I made, I'll keep the post updated.

[Trioxin]

A chest type deep freezer and a washing machine. We'll see in the next few days how hot the wires get and if the breakers trip. I'll continue to post with what I am able to run and what-not.

I run a small Heier chest freezer on my setup. Works great. The thing only pulls like 1.3 amps. Cost around $200 at Wmart.

[Rock2Fox]

My freezer is pretty big, but I eat twice what normal folks do so I really don't know how we ever did without it. That freezer draws 6 amps when the compressor is running, so I am pretty ligit as far as that goes. The washing machine I have yet to try. The surge amps/ watts is pretty ridiculous (or so I speculate), the inverter can definitely handle it, but I am unsure about whether the power draw will be able to be recouped quick enough to make it economically viable (economic in the electricity sense).

[The Syndicate]

Nice setup, I have been looking into something like this myself. The only thing I see a possible problem with is your ground. You really want the rod into wet/moist earth, two feet just sound's awfully shallow.

[E]

Cost-wise, this project quickly became a money pit. I think there are really two mindsets for doing something like this: (1) to try to do if for the least amount of money, and get the most watts/ amps per dollar, or (2) to build a system that is as safe as possible. I made a sort of hybrid attempt of (1) & (2).

A little background info on the project first. I have a gasoline generator to use in emergencies; so one day I told my wife I was going to fill some 55 gallon drums full of gas to keep on hand to use to provide power. I gave her the choice between having a fairly large quantity of flammable liquid in our garage, or spending some cash on an alternative energy source. Thus the genesis of this system.

I first planned on using marine batteries, but based on my needs and not wanting to have a vented battery box which had a way to get rid of the hydrogen by-product of deep cycle charging I chose to spend more money and get the most "maintenance free" batteries I could. I chose the MK/ DEKA 8G4D (I think that is the model, listed at 183 amp hour @ 10hr. rate) $375/ per batt.

As far as the panels, I chose these based on cost, they were $475 + freight from an internet vendor (Mr. Solar). These prices are not awesome, but I believe you get what you pay for and nothing really screamed "quality" on Ebay.

Cables, were not a cost that I considered before hand. This is definitely an area where you could save money if you wanted too. I hope to expand this system as I get more cash, so I opted to buy larger battery cables (#2/0) that would handle the largest loads. I firmly believe that I could have bought #4/0 AWG from Wal-Mart and been just fine with this setup (but I didn't). So all in all the cables cost about $130 (for 2.5' of #2/0 AWG battery cable between the DC breaker and the batteries; 12" of #2/0 battery for parallel wiring as between the batteries; 2.5' of #10 AWG wire as between the charge controller and the batter; 52" of #10 AWG intermodule cables; 25' of #10 AWG output cable, this is basically the same thing as the intermodule wiring, but in a heavy duty light resistant outer insulation; and lastly a 100ft. 12ga. outdoor extension cord).

The UniRac mount ran about $150; Trioxin made his for free, so I don't know if this was necessary, but b/c I live in a VERY windy part of the US, I didn't figure this was an area to cut costs on. Plus I don't have a bed frame or any welding skills.

The Xantrex C40 controller was about $199, w/ the digital display and battery temperature sensor (used to help the controlling functions be more accurate I suppose) added in (purchased new on Ebay).

The Xantrex Prosine 1800w Inverter was the most questionable of my purchases b/c it had been refurbished. However for $460 I took the gamble. A new unit retails WITHOUT a GFCI (the plug for your extension cord) for around $1100. I paid for the name, and paid for the "pure-sine" wave aspect, which I gather you need to run complicated appliances such as laptops and the like.

The DC breaker was $175 including the 150amp breaker; also something you don't need, but it gets me closer to being up to local electrical code and allows me to disconnect the batteries if I ever need to work on the AC side of the system.

The other DC breaker that works as the panel disconnect, is an OutBack solar combiner box which cost $120. Also not exactly necessary, and I'm also not using it for its intended purposes which was to combine multiple panel arrays into one output. But whatever, it is part of what makes this system just a little more expandable in the future.

So the short answer is I spent a LOT of money, MUCH MORE than I intended, but I think it has staying power and will facilitate future upgrades with ease.

Hope this helps.

O.O wow that's a good ammount you spent. I'd love to do this, but it'd have to be on a much much much smaller budget. Still, props for getting it done. One better than me!

[E]

and what type / gauge wires are running from the solar panel?

[Rock2Fox]

I used #10 AWG, 2 conductor, insulated wire (so basically 2 #10 wires, one red and one black inside a thicker outer insulation) 25' feet long between the array and the disconnect.

[Roknrandy]

Nice setup, I have been looking into something like this myself. The only thing I see a possible problem with is your ground. You really want the rod into wet/moist earth, two feet just sound's awfully shallow.

Again nice setup but I agree with Syndicate about the ground. Make sure it's several feet deeper and in a spot where it can be in moist earth. Just trying to point a potential safety problem.

[xxxero]

Very, very nice work.
looks great.

[Rock2Fox]

I did some tests today to see how much energy the various appliances around my house consumed. The results are as follows:

The entertainment system including TV, stereo and satellite box ran about 20 amps.

The laptop, modem, router and cordless phone ran about 5 amps.

A battery charger for my cordless drill ran about 3 amps.

A 10 cubic ft. deep freezer ran 7 amps. (but only when running, which happens for about 4 minutes an hour)

A fluorescent lamp I use as a grow light ran 1-2 amps.

In comparison, this setup produced 21 amps for about 6 hours during the brightest part of the day in direct sunlight, and gradually decreased after about 1600.

I use amps here (whether right or wrong) instead of wattage b/c I measure the batteries' capacity in amp hours. Also, the readout on the inverter has a bar graph for AC watts, but a specific digit for amps so I don't have to guess.

[Doryman]

Nice set-up, and congratulations for climbing above the rest of us mouth-breathing buffoons!!

The expense( and lack of a permanent residence) is definitely going to keep me from doing this anytime soon, but if I ever get a chance I'll be ganking some of your and Trioxin's ideas.

And props on bolting the extinguisher to the rack with all the equipment. I hadn't even thought of fire safety until I saw that!

[colinz]

Nice setup, I have been looking into something like this myself. The only thing I see a possible problem with is your ground. You really want the rod into wet/moist earth, two feet just sound's awfully shallow.

Again nice setup but I agree with Syndicate about the ground. Make sure it's several feet deeper and in a spot where it can be in moist earth. Just trying to point a potential safety problem.

I agree with the Earthing point . There are other alternatives to using copper rod for earthing.

Over here for an Earth Stake we usually use a 1/2" galvanised rod around 6' long, and hammer it in until there is only 6" showing above ground.
If we do use copper rod, it is buried a fairway underground.

[Rock2Fox]

Update on power tests. Running a washing machine has proven too demanding for the system. The washer drew about 1500 watts on its initial surge to start the motor, and maintained its operation at 750 watts/ ~60 amps. It pretty much quit spinning the basket about halfway through the cycle--- I'm not sure exactly why, there should have been enough power in the batteries to make it work, but whatever.

So as of today: 1 freezer, 1 rechargeable battery back for my drill, one cell phone and a "dust-buster" all sucking juice, but not from the grid, from the sun.

[Rock2Fox]

Based on the feedback from this thread I went back to Lowe's and bought another 8' foot section of 3/8" grounding rod. I went to town on that shit with a sledge for about an hour and pounded 5' into the ground, then hit bedrock.

I hope this works better then the original. Thanks for the advice and constructive criticism.

[E]

Update on power tests. Running a washing machine has proven too demanding for the system. The washer drew about 1500 watts on its initial surge to start the motor, and maintained its operation at 750 watts/ ~60 amps. It pretty much quit spinning the basket about halfway through the cycle--- I'm not sure exactly why, there should have been enough power in the batteries to make it work, but whatever.

So as of today: 1 freezer, 1 rechargeable battery back for my drill, one cell phone and a "dust-buster" all sucking juice, but not from the grid, from the sun.

yeah I wouldn't expect the washer to run off a battery pack. No two ways around that, it just takes too much juice

Props on getting the freezer to run off it. If you have an electric water heater, try that as well. Again, nicely done man

[SpecialPatrolGroup]

Very clean setup! I like it and want to build one :D Awesome.
If I would do anything different, I'd move the inverter. Bolt it upside down under the tabletop or something. Maybe you are a very neat person, but when I see a horizontal surface in my life all I see is a place were things will eventually start getting heaped.
Do you have a kill-o-watt? It's a great meter that might help you gauge runtime on things. And yeah the washer just won't go, on paper it might but when it comes down to it you are almost just touching hot and neutral together. Better off being gentle on your rig and having the power available in case of an outage.