Solar project. What am I forgetting. What would you change?

Topic: Solar project. What am I forgetting. What would you change? (Read 1007 times) previous topic - next topic

Solar project. What am I forgetting. What would you change?

May 21, 2020, 01:40:42 pm

Michelin Star Solar Installation for Big Mac price
600 AH Lithium Battery Installation

Great info in the above posts!

$1184 for 1140 watts of solar
Panels seem to be something you can find for a bargain if you are patient and willing to look around.

I have the panels, just need your help in looking over the design so I can order the rest.
I believe I am going to upgrade to the 100/50 controller from Victron. It's only $90*2=$180 more and if I want to add 2 more 285W panels @ $125 at a later time it will handle it. So for $430 approx I could add another 570W and the install on those would be easy, will need to change breakers to 60a & 40a.

I am a complete novice, I need your help in punching holes in this design!
Punch away.

Thanks in advance for putting up with my learning curve, it was steep!
Shout out to the following for talking me through this curve
Pierce Stewart
Chuck "Craneman"
Jack Lewis
Justin @ Bay Marine Supply/ Justin 619-320-5899 ext 105 justin@baymarinesupply.com
Roger Engdahl, didn't talk with Roger but definitely leaned on his post to further my knowledge.

Justin @ Bay Marine said he prefers to over design the panel wattage for the 9 months out of the year that, even in ideal conditions, you will not be able to produce enough solar wattage from your panels to Max out your solar controller. This is due to angle of the sun, dirty panels, no tilt, etc. So in other words don't design the system for the 2-3 hrs of the day in July during ideal max conditions its not cost effective, but having the excess wattage will be most beneficial during the spring/winter/fall periods to get the max wattage out of the system during not ideal conditions.

1140W will, under ideal conditions produce 84A. (285*4=1140/13.5V=84ampsâ€”-he uses 13.5 because it is the approx average between 12.8v & 14.4v for the AGM charge cycle I will have. He thinks on the ideal best of days I would produce 70amps thus he recommended the following for my system. I will could be shedding approx 5amps on the best of days on each string??? Justin said the shedding will not hurt the controllers as they are designed for that.

2 Victron Smart Solar MMPT 100V/30Amp controllers
2 solar panels in parallel to one controller
2 solar panels in parallel to the second controller
They recommend this on boats for redundancy, so if 1 string goes out the other still works. And the best part is its a little cheaper because you use smaller wire and the 2 smaller controllers are cheaper than 1 big. May not be much but every little bit helps

Found on FB marketplace
These were left over from a solar company inventory and bought at a bargain price!
4-285W New Suniva Optimus series mono crystalline solar @$125 ea =$500 total
Per Justin @Bay Marine Supply these panels will produce
285/13.5V=21A each at high noon on the summer solstice with no clouds and clean panels tilted to the correct angle of the sun. Mine will be flat and dirty

All these items were sourced from Amazon total $70

Solar Crimper not essential but wanted the connections done right $12.19
ABN Solar Crimper MC3 MC4 Crimping Tool â€“ MC3 and MC4 Connectors Solar Panel...

Zip Ties for a clean job. $7.79. 1 bag UV rated a must!
Amazon.com: Heavy Duty Zip Ties UV Resistant White 8 Inch Wide 4.8mm Nylon...

Zip tie mounts $8.99 1 bag UV rated a must!
Zip Tie Mount 0.75 Inch 20mm Black Samll Wire Tie Adhesive Mounting, 100...

MC4 Y connectors 2 pair @7.98EA $16 total.
Amazon.com: LINKPAL Branch Connectors Connectors Y Connector in Pair MMF+FFM...

MC4 connectors 1pack of 6pair@7.99
Amazon.com: BougeRV 12 PCS Solar Connectors Solar Panel Cable Connectors 6...

Wire ratchet crimper. Hoping these work better than the ones I have! $16.99
Hilitchi Professional Insulated Wire Terminals Connectors Ratcheting Crimper...

Ebay
Black Solar panel mounts 4 sets of 4. Total eBay $36
RICH SOLAR Solar Panel Z Bracket Brackets Mounting Mount RV Boat Flat Roof...

Total Bay Marine Supply $642-10%=$578
These items will be purchased from Bay Marine Supply/ Justin 619-320-5899 ext 105
justin@baymarinesupply.com. I looked around and you might be able to find a few items at a slightly better price but not enough to be bothered with the hassle. If you factor in the 10% discount for the Foreforum it was a no brainer for me to order from Justin. This doesn't take into account the knowledge he has that is just a phone call away that is free if you buy your stuff from him. It is a priceless asset!

4- Midnight Solar breakers 2-40amp. 2-30amp 4*$13.50=$54
MidNite Solar DC DIN Rail Breakers
40amp between batter and controller is a must
30amp between solar and controller. Not a must but Justin likes to have this so you can isolate the controller and for safety from incoming voltage from the panels.

1- Midnite solar BabyBox $37
MidNite Solar BabyBox

2-100/30 Victron SmartSolar MMPT charge controllers $226*2=$452
Victron SmartSolar MPPT 100/30 with Built-In Bluetooth

1-100' roll of Marine grade duplex flat wire $99
https://baymarinesupply.com/duplex-flat-cable-100-foot-roll.html

Already had the 712 BMV Victron battery monitor but would recommend it for any install $200

Anything I have forgotten?

Re: Solar project. What am I forgetting. What would you change?

Reply #1 – May 21, 2020, 02:20:03 pm

Perhaps I missed it in your list of equipment, but I don't see any switches. I believe it is prudent to have a disconnect switch between the panels and each solar controller, so you can safely isolate the panels (put them out of service) when working on the system.

See the red switches next to my solar controllers in photo below:

Re: Solar project. What am I forgetting. What would you change?

Reply #2 – May 21, 2020, 02:42:22 pm

For an inexpensive quick review of your first system, may I suggest watching "ALL" of the videos from AmSolar. The book by Will Prowse on Solar DIY is also worthwhile, and there is nothing like reviewing the basics before starting your first solar system. This reinforces what you are advised and doing. Listen to and appreciate the advice from Bay Marine, it will prove to be so valuable.

Mobile Solar Power Made Easy!: Mobile 12 volt off grid solar system design...

Check out this forum: DIY Solar Power Forum

https://youtu.be/fFHn_xoMsAs

Re: Solar project. What am I forgetting. What would you change?

Reply #3 – May 21, 2020, 02:44:13 pm

Quote from: Chuck & Jeannie – May 21, 2020, 02:20:03 pm

Perhaps I missed it in your list of equipment, but I don't see any switches. I believe you need a disconnect switch between the panels and each solar controller, so you can isolate the panels (put them out of service) when working on the system.

See the red switches next to my solar controllers in photo below:

Not very good at drawing schematics.

I am using breakers in front of and behind the controller to be able to isolate the panel.

Re: Solar project. What am I forgetting. What would you change?

Reply #4 – May 21, 2020, 02:47:42 pm

Quote from: Tommy D – May 21, 2020, 02:44:13 pm

I am using breakers in front of and behind the controller to be able to isolate the panel.

OK - I see that in your comments now - just missed it. That should work.

Re: Solar project. What am I forgetting. What would you change?

Reply #5 – May 21, 2020, 07:57:21 pm

Here are some general comments.

I am not sure it is best practice to use a breaker as a switch. It is OK but it may degrade the performance of the breaker over time. Consider adding switches.

You might want to add a fuse at the battery end as well.

Are you going to charge your start batteries using solar? How?

My rule of thumb for solar is 4 x 285 watts x 8 hrs of effective sun x 25% efficiency = 2280 watts per day average over the year. Best days maybe twice that. Mid January probably 1/2 of that or less. At 13.5 volts that is about 168 amp hrs. That is about 25% of your capacity. If you are discharging much below 75% SOC there will be the majority of days that you will not recover to 100% SOC which is really critical for your AGM batteries.

It really depends on what you want this to do for you. If it is just supplemental power then it is going to be fine. If you want to be landline and generator free then you really need to know how much power you use, how much storage capacity you have and how much solar you need to balance demand and recharge with production on the worst solar days. So more watts total is always good, make sure you have sufficient capacity in your charge controllers for the peak demand days, any peak solar day's production in excess of what you consume and use for recharging (to your capacity) is excess and if it more than the controller is rated for is just not used. You don't have capacity for storing it anyway. Capacity is important for that off grid overnight in January.

Two charge controllers give you some room to grow but add wiring complexity and more equipment. Maybe on a boat the duplication is good but on land it is probably just duplication. I would expect these charge controllers to last a long time.

I don't see how you are going to save money on wiring. The wire size is directly related to amps and length. And more connections means more places for problems. Keep it as simple as possible.

Your small panel mounts will have to be screwed to the roof structure not just into the roof. They are too small to depend on VHB tape alone. They are designed for a flat roof. On a curved roof the top flanges will not be in the same plane as the bottom of the panel frame. When you bolt them on either the panel frame will twist or the bracket top flange will bend or you will just add stress to the mounting screws.

The plan is sound, maybe some room for improvement but It looks good as is.

A Second House Battery Bank, Solar Panels, 2 New Inverters

Re: Solar project. What am I forgetting. What would you change?

Reply #6 – May 21, 2020, 09:55:20 pm

Thanks for the input!

Quote from: Roger & Susan in Home2 – May 21, 2020, 07:57:21 pm

I am not sure it is best practice to use a breaker as a switch.

You might want to add a fuse at the battery end as well.
In discussing this with Justin at Bay Marine, he said to use one of three for protection between the controller and the batteries 1fuse or 2bussman 187 breaker or the 3midnight solar breaker

Are you going to charge your start batteries using solar? How? Have a trik L start

It really depends on what you want this to do for you.
I want to be able to boondocks for 2-3 days. Not sure the DW will be up for much more than that

Your small panel mounts will have to be screwed to the roof structure not just into the roof. They are too small to depend on VHB tape alone. what size roof mounts do you recommend for VBH tape?

Re: Solar project. What am I forgetting. What would you change?

Reply #7 – May 21, 2020, 10:40:32 pm

Tommy,

I just used a regular stud finder to find the aluminum structural members in the roof and then screwed into them with stainless screws and washers, sealed by GE silicone II. Since the panels are long, I used one more mount midspan on our 77 inch panels. A couple of mounts didn't have any aluminum below so I just drilled and screwed into the roof. It's .400" thick. Again, sealed with Silicone II.

I used the breakers to turn the panels on and off. Two for the panels to controller, two for the controller to battery side. They operate smoothly and have been used hundreds of times without a problem. See in the photos I sent you.

I used a 250 amp fusible link where the solar system ties into the electrical panel. You can see the big arrow pointing to it in the attached photo.

All the top controllers are very reliable so there should be no need to duplicate. Check the ratings at Amazon. Victron contollers lend themselves to mounting in a more confined space and have excellent reviews. My Midnite 150 is taller so needs more vertical space. It's the only one made in the U.S. and the manufacture has overnight replacement as well as factory support. Outback also makes a top controller with top reviews. Also a taller unit if you are tight on space. All these will handle lots of power, more than you will have on your roof.

No real difference in the price of panel wire size so not a factor in wiring parallel, series-parallel or all series. All series with four 36 volt panels will have 144 V, plenty of volts to kill you so keep that in mind.

Will post a schematic of our system when I get a chance.

Avoid repurposed hardware store mounts as they look cheap.

Pierce

Re: Solar project. What am I forgetting. What would you change?

Reply #8 – May 21, 2020, 10:58:20 pm

From eleven years ago, here is the list of parts and sources including prices. Panels are less expensive now.

If you have thought about a DIY solar installation but the sticker price is too much, here is how I did the whole thing using premium components for under $2000. Tim was wondering about the source and pricing so here it is. Anyone with rudimentary skills can repeat this installation. Not including batteries, I spent about $1477

Solar panels are commercial 36 volt Yingli 72 cell, 285 watt. About 6 1/2' by 3 1/2' with aluminum frame. These are used in solar field all over the world. The price was right and I wanted a panel that could push through tree branches without damage. These have done a great job. Any panel that fits is fine if you do a bit of research. Yingli has replaced this panel with a 320 watt version available at discounters for about $195. Craigslist is a super spot for finding solar panels and the posting will be in your area so no shipping and probably no tax. Same goes for deep cycle/solar batteries. The batteries were new from a solar dealer that went bankrupt. Found on Craigslist.

Please PM with any questions

U300 Solar Installation Costs

(4) 36 volt 72 cell Lingli Commercial 285 watt panels Yingli YL280P-35b - 280 Watt 35 Volt Solar Panel New @ $160/each, no tax, no shipping. Source: Sacramento Craigslist. Panels are approx. 6.5' x 3.5', weigh 65 lbs.

Total: $640 for four panels

Wiring: Solar wire connectors $6 delivered Solar Panel Original MC4 Multi Contact Solar Connectors UL for 10 AWG Wire |...
50 feet red, 50 feet black #10 AGW wire at $23/each delivered. 10 AWG Solar Panel Wire 50 039 Power Cable UL 4703 Copper Made in USA PV...

One Midnite Classic 150 MPPT controller @ $495.79 delivered (I paid $612 delivered)
Midnite Solar Classic 150 SL MPPT Solar Charge Controller Regulator 150V 96A...

Insulated Terminal Bus Bar (2) @ $11.15 Insulated Bus Bar - Terminal - Short

Welding Cable (house batteries to controller): approx 20 feet and $70 Welding Cable • Cut by the Foot from Welding Cable • Cut by the Foot from [%url]http://www.wireandcableyourway.com/Welding-Cable/[/url%].62/ft | Wire & Cable Your Way.61/ft | Wire & Cable Your Way

100 amp breaker $40 Midnite Solar MNEPV 150 VDC 80A and 100A Solar Array Breakers
50 amp breakers (2) @ $12.62/ea Midnite Solar 120VAC Breakers, 10 to 60 Amps
Breaker Box $29 Midnite Solar Baby Box Enclosure for 1-4 Din Rail Breakers

Panel Roof Mount Z brackets six sets @$11.90 delivered, $71.40 total Solar Panel Z Bracket Mounting Mount Flat Roof Wall Aluminum Set 4 Pcs Kit...

Box #8 x 3/4" stainless self tapping screws $8.99 delivered http://www.ebay.com/itm/Qty-100-Phillips-Pan-Head-Self-Drilling-Tek-Screws-Stainless-Steel-8-x-3-4-/152121479703?hash=item236b259217:g:GxoAAOSwQoFWQopM

3 lengths of 1"x 2" .125 wall rectangular tubing @ $16.52/ea Aluminum Rectangular Tube From Cardo Industries | CALL (916) 922-7824

Copper 2/0 welding cable lugs (2) @ $5.36 delivered Forney 60098 Cable Lug, #2/0, Copper for sale online | eBay

250 amp fuse for cable to coach electrical bus $7.19 plus shipping Blue Sea Systems 5107 MEGA Fuse 250 AMP/32 VOLT

Thermoplastic 3/4" flex electrical conduit $23.45 delivered http://www.ebay.com/itm/Southwire-Flexible-Conduit-3-4-X-25-Highly-Flexible-/281861155136?hash=item41a03be940:g:br8AAOSw44BYXCas

HardieBacker 1/4" cement backerboard $11.47 Home Depot http://www.homedepot.com/p/James-Hardie-HardieBacker-3-ft-x-5-ft-x-1-4-in-Cement-Backerboard-220022/100183556

Batteries: 6 new Genesis XE70 with metal case surround batteries were purchased from a bankrupt solar company for $35 each. List is $361 each. Source was Craigslist.
http://www.osibatteries.com/p-996.aspx?searchEngineName=enersys-genesis-pure-lead-xe70-0771-6001-battery-12v-68ah&gclid=Cj0KEQiAt9vEBRDQmPSow-q5gs8BEiQAaWSEDvO0vB08rmhmvSWbRDqPZFz2wQUhUEwpWt7dlkClLdYaAq9N8P8HAQ

Re: Solar project. What am I forgetting. What would you change?

Reply #9 – May 21, 2020, 11:24:28 pm

VHB tape on well prepped surfaces has a 91 pounds per square inch tensile strength. A 6"x 1.5" base gets you about 200 pounds vertical lift strength with a safety factor of 4. That is about 800 pounds per panel. I used 12" long mounts, rock solid.

I would add a fuse at the battery end of plus cable to the battery.

Think this through carefully. Ask questions, do it the way it works best for you.

Re: Solar project. What am I forgetting. What would you change?

Reply #10 – May 22, 2020, 12:40:45 am

Quote from: Roger & Susan in Home2 – May 21, 2020, 11:24:28 pm

VHB tape on well prepped surfaces has a 91 pounds per square inch tensile strength. A 6"x 1.5" base gets you about 200 pounds vertical lift strength with a safety factor of 4. That is about 800 pounds per panel. I used 12" long mounts, rock solid.

The tape does work really well. I went with screws in case I wanted to move the panels or change to a different size panel. When I painted our roof, it was easy to hit it with the sander once the panels were removed and then roll and tip.

Pierce

Re: Solar project. What am I forgetting. What would you change?

Reply #11 – May 22, 2020, 11:45:32 am

I use the same Midnite Solar "baby box" with dc breakers, which also doubles being your disconnects between solar panels positive lead and the Victron solar contoler too. Be sure you mount the Midnite dc breakers in the proper direction, as there is a proper in and out direction of dc from the positive panel lead. I questioned this with an Israeli mfg of these dc breakers, and was told if wired in the wrong direction, this could effect the life and protection capability of the dc breaker. On the inverter side I used a properly sized Blue Sea circuit breaker to cutoff solar charge controller to batteries, similar to the following from Bay Marine on Amazon. Bay Marine can advise you on size for your system.

Bay Marine Supply 187 Series Circuit Breaker â€“ 110A Surface Mount 48V DC Max...

I am glad you are buying the items from Bay Marine, that assures you of getting the right enginered items with the proper quality and support. Many buy the lowest priced wire on the web, and end up with copper covered aluminum wire that has higher resistance. The wire from Bay Marine will be 100% copper, as it should be.

There is a proper connect sequence. First connect to batteries, this powers up the Victron solar controller, then connect solar charge controller to panels. Disconnecting is reversed, first disconnect from solar panels then disconnect solar controllers from batteries. Victron manual should be read carefully for a safe install. It will advise on first connection, and on how to update bios if wi fi is available. Double check that you are connecting to the proper posts on the Victron charge controller, double check for proper proper + and - leads from panels with a volt meter. An error here will destroy your Victron charge controller!

Re: Solar project. What am I forgetting. What would you change?

Reply #12 – May 22, 2020, 12:40:57 pm

Quote from: Jack Lewis – May 22, 2020, 11:45:32 am

I use the same Midnite Solar "baby box" with dc breakers, which also doubles being your disconnects between solar panels positive lead and the Victron solar contoler too. Be sure you mount the Midnite dc breakers in the proper direction, as there is a proper in and out direction of dc from the positive panel lead. On the inverter side I used a properly sized Blue Sea circuit breaker to cutoff solar charge controller to batteries, similar to the following from Bay Marine on Amazon. Bay Marine can advise you on size for your system.

Bay Marine Supply 187 Series Circuit Breaker â€“ 110A Surface Mount 48V DC Max...

I am glad you are buying the items from Bay Marine, that assures you of getting the right enginered items with the proper quality and support. Many buy the lowest priced wire on the web, and end up with copper covered aluminum wire that has higher resistance. The wire from Bay Marine will be 100% copper, as it should be.

There is a proper connect sequence. First connect to batteries, this powers up the Victron solar controller, then connect solar charge controller to panels. Disconnecting is reversed, first disconnect from solar panels then disconnect solar controllers from batteries. Victron manual should be read carefully for a safe install. It will advise on first connection, and on how to update bios if wi fi is available. Double check that you are connecting to the proper posts on the Victron charge controller, double check for proper proper + and - leads from panels with a volt meter. An error here will destroy your Victron charge controller!

Jack brings up an excellent point. You DO have to mount the DC breakers in the proper direction. I called the Midnite tech support and they were great explaining which lugs on the breakers when to the panels and which went to the controller side. Same is true on the battery side breakers.

I used a label maker to identify which wire was which when they came down though the roof. Shocked myself several times too.

Even though our Midnite controller has arc protection, the factory recommended flipping the panel breakers off first and then the battery breaker next. Startup is not as critical as the controller has to go through the boot sequence before it goes online.

In the attached photo, you can see the additional labels I put on the breakers above the controller. I didn't want to make a mistake so make sure glance at the label before shutting down.

Nice addition, Jack!

Pierce

Re: Solar project. What am I forgetting. What would you change?

Reply #13 – May 22, 2020, 03:57:16 pm

Lots of ways to get this done. The DC circuit breakers are one way.

I used a six circuit fuse block (three panels are connected in this picture. Each panel has its own fuse. Output from the fuse block goes through a switch. Output from the charge controller is fused at the battery end with an MRBF Battery Terminal Fuse Block and fuse.

Re: Solar project. What am I forgetting. What would you change?

Reply #14 – June 17, 2020, 06:29:18 pm

Finished my install, thanks for all the help!

4x285w=1140watts

Mounted the solar board in the battery bay

I have room for 2 more panels on the front and according to Justin at Bay Marine my solar controllers will handle the extra wattage fine, he said you may have occasional ?shedding? With 2 more but he's okay with more watts than less to help out on the cloudy days.

Re: Solar project. What am I forgetting. What would you change?

Reply #15 – June 18, 2020, 08:00:20 am

Tommy, for those that follow, can you list sources &/or ballpark $$$$$$$$$

Larry

Re: Solar project. What am I forgetting. What would you change?

Reply #16 – June 18, 2020, 08:57:18 am

Quote from: ohsonew – June 18, 2020, 08:00:20 am

Tommy, for those that follow, can you list sources &/or ballpark $$$$$$$$$

Larry

See original start of post

Re: Solar project. What am I forgetting. What would you change?

Reply #17 – June 18, 2020, 11:17:55 pm

Quote from: Tommy D – June 17, 2020, 06:29:18 pm

Finished my install, thanks for all the help!

Looks good Tommy. Solar is a great upgrade. As to adding more only do it if you have room to walk around the roof. You will need up there eventually!

see ya
ken

Foretravel Owner's Forum For owners and Fans of Foretravel Motorcoaches April 24, 2024 ...

Solar project. What am I forgetting. What would you change?

May 21, 2020, 01:40:42 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #1 – May 21, 2020, 02:20:03 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #2 – May 21, 2020, 02:42:22 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #3 – May 21, 2020, 02:44:13 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #4 – May 21, 2020, 02:47:42 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #5 – May 21, 2020, 07:57:21 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #6 – May 21, 2020, 09:55:20 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #7 – May 21, 2020, 10:40:32 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #8 – May 21, 2020, 10:58:20 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #9 – May 21, 2020, 11:24:28 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #10 – May 22, 2020, 12:40:45 am

Re: Solar project. What am I forgetting. What would you change?

Reply #11 – May 22, 2020, 11:45:32 am

Re: Solar project. What am I forgetting. What would you change?

Reply #12 – May 22, 2020, 12:40:57 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #13 – May 22, 2020, 03:57:16 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #14 – June 17, 2020, 06:29:18 pm

Re: Solar project. What am I forgetting. What would you change?

Reply #15 – June 18, 2020, 08:00:20 am

Re: Solar project. What am I forgetting. What would you change?

Reply #16 – June 18, 2020, 08:57:18 am

Re: Solar project. What am I forgetting. What would you change?

Reply #17 – June 18, 2020, 11:17:55 pm

Affiliate Notice