Solar Show and Tell

[blacklab]

That's all good news to hear.

Thank you for the info.

Cheers,

Bryan

[farafield]

Originally Posted by batman

Here is a nice little video demonstrating the effect of angle on PV panels.

-Dennis

That was interesting--thanks!

[AirMiles]

Today I completed installation of 600W of solar on our 27’ Globetrotter. Attached are pictures of the installation and initial performance. Sun conditions were far from ideal with passing showers. The picture with the door open shows sky conditions during the test. Luckily, I caught some hazy sunlight to run an initial test that produced 421W with nearly every 12V appliance and light turned on.

[TouringDan]

Nice work AirMiles. You have a beautiful GT with 600 watts of solar. Other GT owners should really just copy what you have done- a great solar setup at a modest cost that performs very well.

Dan

[pcskier]

VERY nice...terrific panel layout. Ready for pics of the inside now :-)

[farafield]

" Luckily, I caught some hazy sunlight to run an initial test that produced 421W with nearly every 12V appliance and light turned on."

OK, so are you saying that the appliances you have turned on will affect the watt production? I would think that the watt production is what it is regardless of what is running in the GT, i.e. it has to go to the battery first and then go to the appliances. Or does some of the solar production go directly to an inverter and then power the AC stuff? Thanks!

[AirMiles]

Originally Posted by TouringDan

Nice work AirMiles. You have a beautiful GT with 600 watts of solar. Other GT owners should really just copy what you have done- a great solar setup at a modest cost that performs very well.

Dan

Thank you Dan. I believe anyone with a 2017 and up 27' Airstream could copy my installation at a cost of just about $1,800 for 600W self installed. Here is a list of the parts I used:

Six Renogy Compact Solar Panels at $115 ea. https://www.renogy.com/100-watt-12-v...ompact-design/
Six AM Solar 35mm mounting bracket kits $82 ea. https://amsolar.com/rv-mounting-accessories/91m-35ms
One Victron 100/50 SmartSolar Controller $325 https://www.amazon.com/SmartSolar-MP.../dp/B073ZJ43L1
One Victron Smart Battery Sense $40 https://www.amazon.com/Victron-Batte...NBZBCVNTXHR4G0
Five feet of 6/2 duplex $20 https://amsolar.com/rv-cables/cable-6ga-2-gry
Fifty feet of 10/2 duplex $150 https://amsolar.com/rv-cables/cable-10ga-2-gry
One shut off switch $35 https://www.amazon.com/Blue-Sea-Batt...sr=1-6-catcorr
One 60A Breaker $50 https://www.amazon.com/Bay-Marine-Ra...9NQAWAZYX4E1HQ
Various lugs and splices as needed https://amsolar.com/rv-solar-panel-kit/lugs-splices

[AirMiles]

Originally Posted by AirMiles

Thank you Dan. I believe anyone with a 2017 and up 27' Airstream could copy my installation at a cost of just about $1,800 for 600W self installed. Here is a list of the parts I used:

Six Renogy Compact Solar Panels at $115 ea. https://www.renogy.com/100-watt-12-v...ompact-design/
Six AM Solar 35mm mounting bracket kits $82 ea. https://amsolar.com/rv-mounting-accessories/91m-35ms
One Victron 100/50 SmartSolar Controller $325 https://www.amazon.com/SmartSolar-MP.../dp/B073ZJ43L1
One Victron Smart Battery Sense $40 https://www.amazon.com/Victron-Batte...NBZBCVNTXHR4G0
Five feet of 6/2 duplex $20 https://amsolar.com/rv-cables/cable-6ga-2-gry
Fifty feet of 10/2 duplex $150 https://amsolar.com/rv-cables/cable-10ga-2-gry
One shut off switch $35 https://www.amazon.com/Blue-Sea-Batt...sr=1-6-catcorr
One 60A Breaker $50 https://www.amazon.com/Bay-Marine-Ra...9NQAWAZYX4E1HQ
Various lugs and splices as needed https://amsolar.com/rv-solar-panel-kit/lugs-splices

A couple more important pieces:
Three SikaFlex 221 at $15 ea. https://www.amazon.com/Sikaflex-221-...CK1E8CDZE32NXV
Two SAE Connectors at $6 ea. https://www.amazon.com/Nilight-Gauge...NNRWRNHG4AVDJY

[AirMiles]

Originally Posted by pcskier

VERY nice...terrific panel layout. Ready for pics of the inside now :-)

Pictures of the inside wiring are a little difficult to take because of the cramped space. Here is what I did.

I removed the plywood from only the front section of the queen bed to get better access to the front storage compartment. This gave access to the solar prewire and 12V busbars. The busbars are located inside a grey box labeled "Caution 12V DC Panel" see attached picture. The positive wire from the Solar Controller gets connected to the stud on the bottom left corner of the picture, next to where the four gauge red wire is connected. The negative wire from the Solar Controller gets connected to negative bus bar in a large connection next to where the large white wire is connected that can be seen in the bottom of the DC Panel.

I mounted the Victron 100/50 SmartSolar controller, the Blue Sea Switch, and the 60A Bussmann Breaker to a white shelving board approximately 12" x 14". I wired all of that up on my work bench. I then extended the yellow and green Solar Prewires (seen in second picture) about 18" so I could easily connect them with the board and solar controller sitting on top of the bed frame. I also made the 6/2 duplex about 4' long so I could again easily connect it to the 12V DC Panel and the Solar Controller with it sitting on top of the bed frame. After this was all wired up and tested from on top of the bed frame, I then mounted it to the sidewall of the front storage compartment facing the grey 12V DC Panel box. To fit the extra width of the Solar Controller, I needed to move the sidewall of the front storage compartment over about 6" into the front storage area. There are pictures of the completed installation attached. Also, this link gives more detailed pictures of the exact same configuration that I used with my 400W installation on my FC25FB. http://www.airforums.com/forums/f448...ml#post2167314

[Vapilotda]

Originally Posted by AirMiles

Pictures of the inside wiring are a little difficult to take because of the cramped space. Here is what I did.

I removed the plywood from only the front section of the queen bed to get better access to the front storage compartment. This gave access to the solar prewire and 12V busbars. The busbars are located inside a grey box labeled "Caution 12V DC Panel" see attached picture. The positive wire from the Solar Controller gets connected to the stud on the bottom left corner of the picture, next to where the four gauge red wire is connected. The negative wire from the Solar Controller gets connected to negative bus bar in a large connection next to where the large white wire is connected that can be seen in the bottom of the DC Panel.

I mounted the Victron 100/50 SmartSolar controller, the Blue Sea Switch, and the 60A Bussmann Breaker to a white shelving board approximately 12" x 14". I wired all of that up on my work bench. I then extended the yellow and green Solar Prewires (seen in second picture) about 18" so I could easily connect them with the board and solar controller sitting on top of the bed frame. I also made the 6/2 duplex about 4' long so I could again easily connect it to the 12V DC Panel and the Solar Controller with it sitting on top of the bed frame. After this was all wired up and tested from on top of the bed frame, I then mounted it to the sidewall of the front storage compartment facing the grey 12V DC Panel box. To fit the extra width of the Solar Controller, I needed to move the sidewall of the front storage compartment over about 6" into the front storage area. There are pictures of the completed installation attached. Also, this link gives more detailed pictures of the exact same configuration that I used with my 400W installation on my FC25FB. http://www.airforums.com/forums/f448...ml#post2167314

Is all of this done with the factory wiring to the roof? Series/parallel to the 3 ports on the roof?
I did the charge controller work this summer and plan on putting 4 panels on the roof (removing the factory 2) but if I can do 6, that will work too!

[AirMiles]

Originally Posted by Vapilotda

Is all of this done with the factory wiring to the roof? Series/parallel to the 3 ports on the roof?
I did the charge controller work this summer and plan on putting 4 panels on the roof (removing the factory 2) but if I can do 6, that will work too!

Yes! All done on the factory prewire using the factory three-port Zamp rooftop box. The key is three sets of two 100W series-parallel connected panels and a 50A MPPT solar controller. This doubles the voltage and halves the amps moving across the 10 gauge prewire from the rooftop box to the controller. The 600W series-parallel double-double efficiency gain reduces the voltage drop across the 10 gauge prewire to equal the voltage drop of 600W of parallel configured panels on 4 gauge wire between the rooftop box and the solar controller. There is no need to install 4 gauge wire for 600W as the prewire is just as efficient when the series-parallel configuration is used.

Now there is an ongoing debate whether panel shading will cause problems with the series-parallel configuration. I've documented over 240 days of usage with my 400W series-parallel configured Airstream over the past 18 months and panel shading has never been an issue. There's been only five times that I needed to use my generator to boost charge my batteries in those 240 days and the series-parallel configuration was not the factor that caused generator charging. It was always caused by a FULL canopy of Maple trees or a significant canopy of trees combined with dark rain cloud conditions that cause me to need to use my generator. A full parallel configuration will also not work with the lack of light from either of those situations.

I've done tests with panel shading on series-parallel. If one panel is completely shaded with a towel, you will lose two panels, one more than parallel. If two panels are completely shaded, you will lose two panels, the same as parallel. If three panels are shaded, you will lose three panels, the same as parallel. If all panels are shaded, you will lose all panels, the same as parallel. There's really no difference with panel shading except when a single panel is shaded where series-parallel will lose two panels versus parallel's loss of one panel. I believe with six panels, the same thing will happen. When a single panel is shaded, you will lose two. After that the MPPT controller is smart enough to reconfigure to be equal in all other shading situations. That's what an MPPT controller does - it tries various configurations and uses the one that supplies the greatest amount of power output given the sunlight input. Also, in real life, panel shading is not as drastic as covering a complete panel with a towel and therefore the panel losses are no where near as significant when affected by actual tree canopy. I've also documented this occurrence throughout this thread.

I will be doing much more testing with 600W of series-parallel configured solar on the factory prewire and documenting the performance on this thread.

[uncle_bob]

Originally Posted by farafield

" Luckily, I caught some hazy sunlight to run an initial test that produced 421W with nearly every 12V appliance and light turned on."

OK, so are you saying that the appliances you have turned on will affect the watt production? I would think that the watt production is what it is regardless of what is running in the GT, i.e. it has to go to the battery first and then go to the appliances. Or does some of the solar production go directly to an inverter and then power the AC stuff? Thanks!

Hi

Watts is a measure of energy used.

Solar panels that just get hit with sun, but are not loaded in any way produce no watts at all. Put another way, they have volts, but no current is flowing. Watts is volts times amps.

In order to come up with real power delivery you need to fully load the solar setup. One way to do that is with a lithium bank that is discharged. (Lead acid's may or may not do the trick). Another practical way is to turn on all the loads, including the inverter.

As an example:

Right now I'm on shore power. My solar still delivers power into the system. I can see it on the 712. What I'm getting each day from solar is *not* what the panels can deliver. It also is not what is being used by the trailer. The inverter / charger is delivering most of what is getting used.

Bob

[AirMiles]

Originally Posted by farafield

" Luckily, I caught some hazy sunlight to run an initial test that produced 421W with nearly every 12V appliance and light turned on."

OK, so are you saying that the appliances you have turned on will affect the watt production? I would think that the watt production is what it is regardless of what is running in the GT, i.e. it has to go to the battery first and then go to the appliances. Or does some of the solar production go directly to an inverter and then power the AC stuff? Thanks!

Sorry, I missed this question until now. Thanks Bob for your answer.

I'm also confused on how this all works. 1) My 230AH 12V batteries are connected to the busbars. 2) My 600W of solar is connected to the busbars. 3) My Airstream draws power from the busbars. Where the power is actually coming from is a bit of a mystery.

When the sun is shining brightly and I have a 30A draw from the Airstream, is the power flowing through the battery? I think the battery is needed to make it all work. Its like having a 5 gallon bucket of water (230AH Battery) where three quarts of water per hour is pouring out (30A draw from Airstream) and four quarts of water per hour are available to be poured into the bucket if not full (40A available on sunny day from solar). It really doesn't matter if water (power) coming from the bucket (battery) or the flow (solar charging). I think what's most important is that the bucket (battery) is staying full as water (power) is being drawn.

Does this make sense? Can you explain it better Bob or anyone?

I can explain how the wet cell battery works in this scenario. My batteries are fully charged at 13.8V and floating. I turn on all my 12V power appliances with about 30A of draw. My battery immediately drops to 12.3V which tells my solar controller to return its voltage to 14.6V. The solar controller drops down into Bulk mode and the battery voltage goes up to about 13V. The voltage climbs until 14.6V in Bulk mode and then switches to Absorption mode. The solar charger stays in Absorption mode until Amps drop to low single digits and stabilize, when it then drops back into Float mode. When I turn off all 12V draws, Amps drop to low single digits and the solar controller goes back to Float mode in a matter of a few minutes since the battery is again fully charged. Pretty cool if you ask me. I can use 30A all day and still have full batteries at dusk!

I'm not sure how this would work with Lithium batteries. Lithium voltage will not drop like wet cells, so will the solar charger immediately drop into bulk mode and keep the Lithium batteries fully charged like it does with wet cells?

[uncle_bob]

Hi

Well you draw up the circuit and then use the Norton and Thevinin stuff to work out what goes where. Basic EE201 sort of stuff ( Yes, that's no help at all is it ..... )

Simple answer is that you have multiple voltage sources and multiple loads. The resistance between those sources and the loads will determine what goes where. The battery can act as either a source or a load depending on it's state of charge. The solar and converter / charger are just sources. They pretty much don't act as loads.

Next layer to the onion is that the solar and the converter charger may well "back off" as they get close to the target voltage. They also may go into equalize mode ( 14.x V) for a while. As they do all that the "what goes where" changes.

Indeed, if you are on shore power and you get part of your energy from solar, who cares? As long as the load gets powered up, all is well. The battery voltage will bobble around a bit as loads and sources change. Again, who cares? The amount of current in or out of the battery bank is trivial in this case. Yes, it might take the "estimated" life of your lithiums from 120 years down to *only* 119 years. My guess is that past 100 years, you likely will not be to concerned about how they are doing ....

Bob

[Garfish]

May have missed it in earlier post but seems the SAE connection is not secure as solar wires have to do U turn and connector could slip out as it leans a bit towards solar wire. Mine is a MC4 to SAE adapter. Anyone secure better?

Also, since the 3 separate SAE ports all go to just one set of pre wires for controller that this means pre-wire is parallel?

[AirMiles]

Originally Posted by Garfish

May have missed it in earlier post but seems the SAE connection is not secure as solar wires have to do U turn and connector could slip out as it leans a bit towards solar wire. Mine is a MC4 to SAE adapter. Anyone secure better?

Also, since the 3 separate SAE ports all go to just one set of pre wires for controller that this means pre-wire is parallel?

Yes, the Zamp Rooftop Box is parallel. What makes connecting to it series is to connect the positive wire from one solar panel to the negative wire of the other solar panel. Then connect the remaining positive wire from one solar panel to the positive of the SAE connector and the negative wire from the other solar panel to the negative of the SAE connector. See "series connection" diagram in this link: https://www.renogy.com/blog/should-i...-or-in-series/ Series connections can be done on up to three sets of two 100W panels, totaling up to 600W, connected to the three ports on the Zamp Rooftop Box with voltage drop of less than 2% over the 10 gauge solar prewire.

I used these SAE connectors which never came undone for tens of thousands of miles: https://www.amazon.com/Nilight-Gauge...l%2C166&sr=8-3 I put a zip tie double stick tie down within 12" of the SAE connector to help keep it securely connected to the rooftop box. https://www.amazon.com/dp/B07L4CX58B..._t2_B079BGY38V

[Garfish]

Air Miles - I have 2 100 watt Renogy panels wired in parallel using the Renogy connectors so one neg and one pos going back to the same SEA adapter you show. Just bought the zip ties at Amazon, just what I was looking for.

Just don’t quite understand the other two zamp inputs. If I were to have plugged one panel to each would that have given me the same parallel set up?

[AirMiles]

Originally Posted by Garfish

Air Miles - I have 2 100 watt Renogy panels wired in parallel using the Renogy connectors so one neg and one pos going back to the same SEA adapter you show. Just bought the zip ties at Amazon, just what I was looking for.

Just don’t quite understand the other two zamp inputs. If I were to have plugged one panel to each would that have given me the same parallel set up?

Yes, you can connect both positives and both negatives to one SAE connector on the Zamp Rooftop Box (like your picture), or you can connect each panel to separate SAE connectors on the rooftop box, to have two parallel connected panels. With two or three panels, I would connect them in parallel. With four panels, you could use parallel or series-parallel (I would do series-parallel). With six panels, you must use series-parallel if using the Zamp Rooftop Box and Solar Prewire.

[farafield]

Originally Posted by uncle_bob

Hi

Watts is a measure of energy used.

Solar panels that just get hit with sun, but are not loaded in any way produce no watts at all. Put another way, they have volts, but no current is flowing. Watts is volts times amps.

In order to come up with real power delivery you need to fully load the solar setup. One way to do that is with a lithium bank that is discharged. (Lead acid's may or may not do the trick). Another practical way is to turn on all the loads, including the inverter.

As an example:

Right now I'm on shore power. My solar still delivers power into the system. I can see it on the 712. What I'm getting each day from solar is *not* what the panels can deliver. It also is not what is being used by the trailer. The inverter / charger is delivering most of what is getting used.

Bob

Thank you Bob. I may need another cup of coffee for this. A video earlier in the thread provided by Batman Dennis touched upon the watt volt amp thing. The watts never changed while the other numbers did. I should have remembered that when asking this question but you are expounding a bit more on the why and how. Your input is greatly appreciated!

[uncle_bob]

Originally Posted by farafield

Thank you Bob. I may need another cup of coffee for this. A video earlier in the thread provided by Batman Dennis touched upon the watt volt amp thing. The watts never changed while the other numbers did. I should have remembered that when asking this question but you are expounding a bit more on the why and how. Your input is greatly appreciated!

Hi

I most certainly get things crossed up in a post from time to time so no problem.

Bob