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Author Topic: My 2kW solar project  (Read 1768 times)

Desert_Rat

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My 2kW solar project
« on: December 27, 2016, 08:26:04 PM »
I'm retiring this year (hopefully) and I've wanted forever to visit each of this country's national parks: http://www.printableworldmaps.net/wp-content/uploads/2016/07/usa-national-parks-map-mapstillnational-parks-of-the-united-states-NufrvB.jpg

And I've wanted to do this unencumbered by grid power or a noisy, intrusive generator. I want to take full advantage of my country's landmarks, go where I want to go and take full advantage of BLM. But I'm still going to need a lot of electricity to do so comfortably.

Typical week's power usage: 100kW. Off road goal to decrease that to 75~kW. Easy, i think.
Goal: A solar system that will provide that 10~kW per day, given that 'a day' is actually only 9~ hours of sun in the months I'll be traveling. So... 1~kW per hour of solar and substantially more in battery storage.

On this: http://imgur.com/a/ZjUOJ

First issue is where to stick almost 3,000AH of batteries on a camper with no space (yes, if I had a 5th wheel this would likely be a little easier).
Then is where I place the 2 large electronics (inverter/charger, mppt).

Lastly is where - lol - 2kW of PV is going!

With no other options that I could find,
the batteries are going here:  http://imgur.com/a/eYp1l
and the electronics are going here:  http://imgur.com/a/Y9LXW

Desert_Rat

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Re: My 2kW solar project
« Reply #1 on: December 27, 2016, 08:42:20 PM »
First hurdle, electronics:

Given that I could always hear when my stock inverter kicked in, I wanted to place the presumably louder electronics as far away from my living and sleeping areas as possible. and also as close to the battery bank so as not to lose too much of its voltage. The kitchen area seemed perfect and it also had a cubby hole for my slider pump that I could work with.

From this:  http://imgur.com/a/QcWPJ
Through this:  http://imgur.com/a/XikbR
To this:  http://imgur.com/a/KBmKs

Only the inverter is installed for now because my panels are going up later. But I found enough space to add both. SoundX for noise and spray foam has been added for sound/insulation. This area under my kitchen cabinets has been reinforced with 3/4" plywood to handle the weight of 50~lb electronics.

Edit: the larger hatch door was purchased on eBay for $40. Anyone need a smaller one?  8)


« Last Edit: December 27, 2016, 08:48:11 PM by Desert_Rat »

HueyPilotVN

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Re: My 2kW solar project
« Reply #2 on: December 27, 2016, 09:08:01 PM »
Good Luck with your project.

I did something similar last year.  I do have a couple of comments and possible suggestions.

I am not sure how much the battery bank that you are planning will weigh but it might create a situation if it is all located on the tongue of your trailer.

I mention this because my batteries weigh several hundred pounds and are divided into four discrete battery banks in different locations.

I distributed them into different systems because of how I use them and the differences in charging profiles for the different batteries and controllers.

I am sure that you have researched the issues related to cable size, run length, types of controllers and battery monitors.

Here is the link to my installation with comments from others here on the forum.

http://www.rvforum.net/SMF_forum/index.php/topic,90672.0.html

Again Good Luck with your project. 
Bill Waugh
40' Country Coach DP
34' Stacker Trailer, Trailer Toad
Jeep Commander
Mustang Bracket Race Car
35 years on the road

Desert_Rat

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Re: My 2kW solar project
« Reply #3 on: December 27, 2016, 09:24:39 PM »
OK, I have now got to beg you you to pay attention to my project because you have obviously lived through everything I'm about to. Nice job. Really, really nice.

As far as my future tongue weight, I concur. Now, I really had no choice as the possibility of splitting the bank up doesn't even exist, but I am concerned. I've posted about it elsewhere.

HueyPilotVN

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Re: My 2kW solar project
« Reply #4 on: December 27, 2016, 09:52:08 PM »
Thanks for the response.

There are several other members for example Kevin Means, Lou, Gary. to name a few that will chime in and give you great feedback.

Take your time and you can save time and money with the suggestions from these guys.

With a screen name like Desert Rat are you located in Arizona?
Bill Waugh
40' Country Coach DP
34' Stacker Trailer, Trailer Toad
Jeep Commander
Mustang Bracket Race Car
35 years on the road

Paul & Ann

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Re: My 2kW solar project
« Reply #5 on: December 27, 2016, 09:57:46 PM »
I am not sure how much research you have done on going solar, but here are two sites that have a wealth of information on solar.

http://www.jackdanmayer.com/rv_electrical_and_solar.htm

https://handybobsolar.wordpress.com/

Paul & Ann  Iowa
2005 Winnebago Voyage 38J
http://stoughrvadventure.blogspot.com/

Desert_Rat

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Re: My 2kW solar project
« Reply #6 on: December 27, 2016, 10:00:08 PM »
Texas, but i'll be there soon enough  :D

Desert_Rat

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Re: My 2kW solar project
« Reply #7 on: December 27, 2016, 10:09:56 PM »
I am not sure how much research you have done on going solar, but here are two sites that have a wealth of information on solar.

http://www.jackdanmayer.com/rv_electrical_and_solar.htm

https://handybobsolar.wordpress.com/

Actually, the straight solar wiring hasn't been as difficult to understand as the RV specific issues. For examples: eliminating and merging the stock converter; how to have the RV manage a 24v battery bank, made necessary because of the system's size (and I really should have gone 48v); JFC, my slider's hydraulic pump requires up to 100 amps DC! at 12v!

That last issue I was tackling today. I've resolved to use a separate, small 220CA battery to power it. Would you know if that will work? I'll need some 12v battery that is small but still enough to supply 40+ amps for a good 30 seconds, and will likely have to experiment with a few to find one that will work.

glen54737

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Re: My 2kW solar project
« Reply #8 on: December 28, 2016, 08:43:38 AM »
You could also use a voltage divider to get 12vdc for the applications that are too hard to change.
2018 Thor Miramar 35.2
2015 F-350 CC short box 6.7l 3.55 axle
2015 Alpine 3510RE-sold

Glen,Nene
Mickey & Jayco (yorkies)

Desert_Rat

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Re: My 2kW solar project
« Reply #9 on: December 28, 2016, 10:16:39 AM »
Do you mean step down converter?

If so that is an applied solution here. A 40 amp 24 > 12v step down to handle all my DC powered outlets and devices. Except the slider motor. I couldn't find a quality 24 > 12v step down that supported 100 amps so I sought another solution.

There are two companies that offer a 100a step down that i could find; one is in China and the unit looks kinda junky. The other is Surepower which is finishing a recall of their prior unit. If someone knows of a proven solution that works, I'm all ears.

glen54737

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Re: My 2kW solar project
« Reply #10 on: December 28, 2016, 01:49:28 PM »
No it's just a basic dc circuit two equal resistors in series. The voltage across 1 resistor is 1/2 of the total. finding components  strong enough will be the hard part.
2018 Thor Miramar 35.2
2015 F-350 CC short box 6.7l 3.55 axle
2015 Alpine 3510RE-sold

Glen,Nene
Mickey & Jayco (yorkies)

Lou Schneider

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Re: My 2kW solar project
« Reply #11 on: December 28, 2016, 06:05:12 PM »
The problem with using step down resistors is the voltage dropping resistor wastes as much power as you use in the 12 volt load.  In other words, the conversion loss is 50%.

It's much better to use a switching power supply style voltage converter where the conversion loss is only a few percent and the vast majority of the power reaches the load.
« Last Edit: December 28, 2016, 06:09:40 PM by Lou Schneider »

Desert_Rat

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Re: My 2kW solar project
« Reply #12 on: December 28, 2016, 07:16:42 PM »
The AIMS unit I've purchased claims 94% efficiency, not that I don't get your drift. I originally wanted to run the battery box at 12v but found doing so almost impossible (would need a 175A MPPT, if one even exists) with 2+K of PV. Or I could have installed 2 MPPT's, but with that I don't have the space.

Using a fairly efficient step down seemed the best solution, with priority given to AC. My lights, stereo, water pump (when needed), slider (when needed), and switches use DC. All pretty low continual use amperage. I need to max out my AC instead.

HueyPilotVN

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Re: My 2kW solar project
« Reply #13 on: December 28, 2016, 07:32:19 PM »
The AIMS unit I've purchased claims 94% efficiency, not that I don't get your drift. I originally wanted to run the battery box at 12v but found doing so almost impossible (would need a 175A MPPT, if one even exists) with 2+K of PV. Or I could have installed 2 MPPT's, but with that I don't have the space.

Using a fairly efficient step down seemed the best solution, with priority given to AC. My lights, stereo, water pump (when needed), slider (when needed), and switches use DC. All pretty low continual use amperage. I need to max out my AC instead.

Here is something that you might want to consider.

In the link that I posted I mentioned using the Blue Sky Network configuration.  One of the charge controllers acts as the Master Controller and you can add several 40 amp networked MPPT controllers to increase the charging capacity up to well over 200 amps.  This system allows for expansion as you add panels or you can set up the full charging capacity up front.  One of the benefits is that each charge controller is wired separately and can feed either a single large battery bank or separate battery banks.

Using this network you can maintain a large 12 volt system or several systems and distribute the weight of the batteries rather than having too much tongue weight as mentioned before.

You might want to do some research on the Blue Sky website.

Edit:

I just copied this explanation from the manual.

INSTALLING A MULTI-CONTROLLER SYSTEM USING THE IPN NETWORK
  The 3000i may also serve as an IPN Network Master controlling up to 7 remote IPN Network compatible Slaves. Any Blue Sky Energy charge controller capable of operating as an IPN Network Slave may be used, and as of this writing include; SB3024i SB3024Di, SB3024iL SB3024DiL, SB2512iX, SB2512iX-HV, and SB1524iX. Another 3000i cannot be used.
  Controller types and their PV modules may be different. Each controller is installed as a separate standalone charging source connected to the battery and are then networked together. The 3000i serves as the charge control and network communication Master, controls the charging process, and directs the activities of one or more Slaves. No additional communication hardware or software is required to setup or operate the network. A network communication link is established between controllers by daisy chaining a twisted pair cable from the IPN Network terminal block, controller to controller (A-to-A, B-to-B) as shown in Figure 6. Up to 8 IPN based charge controllers can be connected together in a multi-controller system. The 3000i is fixed as device address 0 (zero) and serves as the IPN Network Master. Attached controllers are configured as Slaves set to addresses 1 through 7. 
  If an optional battery temperature sensor is used, only one is required and it must be connected to the 3000i (Master) to be recognized and shared. Optional displays or UCM may connect to any controller on the network.

As I understand this system you could use a 3000I (30 amp mppt) with 7 SB2034iL controllers (40 amp) for a combined charging of 310 amps.

The Charge controllers are not very big.  The pictures are in the linked post above, one of a 2034 and the other of a 3000I and a network monitor.

A good analogy for this method of charging is that instead of having a fire hose filling a swimming pool you have several garden hoses.  (ie several smaller cables rather than one monster cable).

Another advantage is that a shadow or other problem will only effect the controller output for those panels shaded even though the Master controls all the slave controllers.



« Last Edit: December 28, 2016, 08:27:34 PM by HueyPilotVN »
Bill Waugh
40' Country Coach DP
34' Stacker Trailer, Trailer Toad
Jeep Commander
Mustang Bracket Race Car
35 years on the road

Desert_Rat

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Re: My 2kW solar project
« Reply #14 on: December 29, 2016, 10:16:35 AM »
I considered the multiple MPPT approach but, as you point out, its great advantage is PV expansion. There will be no expansion of my setup unless PV cells greatly decrease in size or increase in efficiency, and neither are on the horizon. As far as using multiple CC's for the specific purpose of sticking to 12v, well, the other issues with 12v setups are: less efficient conversion to 110v and more stress on that inverter, fatter cables throughout, and a doubling of amperage running through all those cables. 12v would have resolved one thing for me: ease of running my DC stuff, but it would have introduced a slew of other issues.

Going 24v has been a struggle, but less so then going 12v. I still think 48v could be better for me, however, to give you an idea on how limited in space I am, 48v was specifically rejected because I can't fit the larger electronics in the space I chose to utilize, and they're quite a bit more expensive too. Going 24v has been a concession after weighing a number of factors.

Desert_Rat

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Re: My 2kW solar project
« Reply #15 on: January 22, 2017, 04:58:45 PM »
After further deliberation I have decided (I think  ;D) to purchase a different PV.

The 340w units (https://www.altestore.com/store/solar-panels/solarworld-340-watt-solar-panel-sunmodule-sw340-xl-mono-p40538) were going to require me removing my overhead AC - which at 1800w and its noise I've always been fine with (worst case, I add another cooling solution like in my bedroom) - but also shadow/shade concerns were probable. They're just so damn big. There was also the issue of getting around up on the roof. It would be possible but certainly more difficult.

Problem was, there was no better solution to 2kw that I could find. The 100 watters (42x26") were too inefficient for their size and all the 200w and higher were all the same size. The flexibles come with a pretty bad rep nor could they be tilted. I didn't see much of a choice.

Then I saw these yesterday: https://www.amazon.com/Solar-Panel-Charging-Battery-Efficiency/dp/B00G2IZ1VW/ref=sr_1_2?ie=UTF8&qid=1485120202&sr=8-2&keywords=everbright+165. The length (59") is very manageable but more importantly, their width (26.5") allows me to easily install 12 of them (14 max). Cost is comparable although I doubt they're made as well as the Solarworld units. But even that may be a wash because of these units smaller size, hence less stress on them when my camper is bouncing up and down roads.

Yeah, I think this is the deal. Midnight Solar's Classic 150 or 200 will both handle 3x4 array.

Comments?

EDIT: Not to scale, but a good idea on layout.
« Last Edit: January 22, 2017, 05:05:52 PM by Desert_Rat »

HueyPilotVN

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Re: My 2kW solar project
« Reply #16 on: January 22, 2017, 05:30:46 PM »
These panels will make several things easier.

You can use "Z" brackets or Tilt Bars to mount them and eliminate the supporting grid structure that the residential panels needed.

You can still wire them in sets of 2 series wired panels to support a 24 volt system if you stay on that plan.

It will be easier to design a layout to avoid shadows and to work around the A/C.

These are similar to the 10 panels that I used between the coach and stacker.

Bill Waugh
40' Country Coach DP
34' Stacker Trailer, Trailer Toad
Jeep Commander
Mustang Bracket Race Car
35 years on the road

Desert_Rat

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Re: My 2kW solar project
« Reply #17 on: January 22, 2017, 05:37:00 PM »
Your first image shows these 4x8 cells as well, who is manufacturer? The only one's I've been able to find are these Everbright's, and Go Solar has them too. Not thrilled with either company.

HueyPilotVN

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Re: My 2kW solar project
« Reply #18 on: January 22, 2017, 05:44:46 PM »
I got my last 3 from Home Depot.  They were on sale for about $200 for 160 watt panels

160-Watt Monocrystalline PV Solar Panel for Cabins, RV's and Back-Up Power Systems

You can order them online and they will deliver them to the closest Home Depot free.

The better price that you found might be offset by the shipping quoted there.

Here are the details and product codes.

Product Qty
Ordered Qty
Shipped Unit
Price Total
 
160-Watt Monocrystalline PV Solar Panel for Cabins, RV's and Back-Up Power Systems

Internet #: 202959994
UPC Code: 855172003058
Return Policy: A

Qty Ordered: 3
Qty Shipped: 3
Unit Price: $229.99
Total: $689.97 3 3 $229.99 $689.97
 
Zippity Feet Z-Mount for Small Off-Grid Solar Panels

Internet #: 205481382
UPC Code: 855172003577
Return Policy: A

Qty Ordered: 5
Qty Shipped: 5
Unit Price: $15.02
Total: $75.10 5 5 $15.02 $75.10
 
6 in. MC4 to Bare Conversion Cable Set

Internet #: 202959960
UPC Code: 855172003126
Return Policy: A

Qty Ordered: 3
Qty Shipped: 3
Unit Price: $10.88
Total: $32.64 3 3 $10.88 $32.64
 
 
Subtotal $797.71
Promotional Discounts -$90.00
Shipping $0.00
Estimated Sales Tax $48.65
Order Total $756.36
 

« Last Edit: January 22, 2017, 05:50:17 PM by HueyPilotVN »
Bill Waugh
40' Country Coach DP
34' Stacker Trailer, Trailer Toad
Jeep Commander
Mustang Bracket Race Car
35 years on the road

HueyPilotVN

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Re: My 2kW solar project
« Reply #19 on: January 22, 2017, 05:57:17 PM »
I also ordered 5 sets of 4 "Z" brackets because I used 6 per panel for extra support and holding ability. 

The MC4 connectors plugged into the lead from the panels and I used 10 ga UV protected cable to run to the combiner box.

The older panels are Kyrocera (sp)

Edit:  The cost per panel was $199.  See the $90 promotional credit above in the totals.

Edit:  I just went to the Home Depot web site and the 160 watt panels are discontinued but they do have 180 watt panels.
« Last Edit: January 22, 2017, 06:26:40 PM by HueyPilotVN »
Bill Waugh
40' Country Coach DP
34' Stacker Trailer, Trailer Toad
Jeep Commander
Mustang Bracket Race Car
35 years on the road

Desert_Rat

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Re: My 2kW solar project
« Reply #20 on: January 22, 2017, 06:34:51 PM »
Discontinued.

Bit more expensive through Amazon:  https://www.amazon.com/Grape-Solar-GS-S-160-Fab8-Monocrystalline-160-watt/dp/B00GGCK7IQ

EDIT: 
Edit:  I just went to the Home Depot web site and the 160 watt panels are discontinued but they do have 180 watt panels.

http://www.homedepot.com/p/Grape-Solar-180-Watt-Monocrystalline-PV-Solar-Panel-for-Cabins-RV-s-and-Back-Up-Power-Systems-GS-STAR-180W-US/301024442

That ain't bad. 75% more expensive but 20 more watts at same width. Very interesting.
« Last Edit: January 22, 2017, 06:42:05 PM by Desert_Rat »

Desert_Rat

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Frank B

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Re: My 2kW solar project
« Reply #22 on: February 10, 2017, 06:05:00 PM »

HueyPilotVN


I notice that in the pictures you post of your installation - the second picture, you likely have a shading problem early or late in the day beside what may be an air conditioner at the far end of your unit, as well as the dome antenna.  Perhaps the same thing with the MaxAir vent just forward of the dome antenna?  Do you have any issues with this?  Or is the shading so late or early in the day that it really doesn't matter anyway?


Thanks.


Frank.

Linux:  Free, open, elegant.
06 GMC 3500 Duramax crew/long pulling 2010 Arctic Fox 30U with 1700 lb Reese Titan Class 5.
1.2 kw solar

HueyPilotVN

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Re: My 2kW solar project
« Reply #23 on: February 10, 2017, 07:35:43 PM »
HueyPilotVN


I notice that in the pictures you post of your installation - the second picture, you likely have a shading problem early or late in the day beside what may be an air conditioner at the far end of your unit, as well as the dome antenna.  Perhaps the same thing with the MaxAir vent just forward of the dome antenna?  Do you have any issues with this?  Or is the shading so late or early in the day that it really doesn't matter anyway?


Thanks.


Frank.

The solar panels on the coach have tilt mounts and when I have a choice when boondocking I plan to park with the drivers side facing south.  Most of the time lately I have been in resorts with full hookups.

I added all this solar as a project to be self sufficient.  My battery monitors rarely show less than 100%.  I really need to boondock more.

« Last Edit: February 10, 2017, 07:37:33 PM by HueyPilotVN »
Bill Waugh
40' Country Coach DP
34' Stacker Trailer, Trailer Toad
Jeep Commander
Mustang Bracket Race Car
35 years on the road

 

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