Question regarding design of a solar installation

[jackbefus]

We just purchased a 2021 22MLE that has provisions for solar on the roof (dock, I think they call it) and wires from the roof running to a small plastic keeper sort of thing in the pass through. It also has a 120v/propane fridge. We have not clearly defined our needs, but we would like to size the system for longer trips without shore power availability, keeping minimum electrical running, that being lights, fridge, a few minor ac drains, etc. (possibly a small electric heater, if possible)

Wondering if anyone has a good basic primer on solar modifications with some dos and don'ts and design ideas.

Thanks so much, folks.

[acoleman43]

We just purchased a 2021 22MLE that has provisions for solar on the roof (dock, I think they call it) and wires from the roof running to a small plastic keeper sort of thing in the pass through. It also has a 120v/propane fridge. We have not clearly defined our needs, but we would like to size the system for longer trips without shore power availability, keeping minimum electrical running, that being lights, fridge, a few minor ac drains, etc. (possibly a small electric heater, if possible)

Wondering if anyone has a good basic primer on solar modifications with some dos and don'ts and design ideas.

Thanks so much, folks.

Well, get ready to head......




My first suggestion is to take your trailer out several times and do an energy audit. Find out how much energy you will want to have available on a daily basis (a 24 hour period). This will determine your solar/battery setup.

You will find this to be a slippery slope.....if I just spend a few hundred more here I will be able to.......over and over until you find yourself at $10.

Seriously, I would first, figure out how much energy you really want each day and what you are spending it on (microwave, air conditioning, etc.). I think you will be surprised by what you find. Knowing this will tell you how many batteries, and solar panels you will need which will help determine the appropriate equipment to send you the harnessed energy.

[Country Campers]

Have a read of the .pdf file in post 1 in this thread Presentation Materials for Solar-101 Discussion at the 2019 Elkhart National Rally - Grand Design Owners Forums (gdrvowners.com)

Brian

[howson]

jackbefus -- a fantastic primer is Will Prowse's Mobile Power Made Easy. Worth every penny to understand before spending money or attempting to design a system. (I read it multiple times when I was in your place.) https://www.amazon.com/Mobile-Solar-.../dp/B09GCPB8Q8



Howard

[jackbefus]

Well, get ready to head......




My first suggestion is to take your trailer out several times and do an energy audit. Find out how much energy you will want to have available on a daily basis (a 24 hour period). This will determine your solar/battery setup.

You will find this to be a slippery slope.....if I just spend a few hundred more here I will be able to.......over and over until you find yourself at $10.

Seriously, I would first, figure out how much energy you really want each day and what you are spending it on (microwave, air conditioning, etc.). I think you will be surprised by what you find. Knowing this will tell you how many batteries, and solar panels you will need which will help determine the appropriate equipment to send you the harnessed energy.

Thanks very much for the graphic, Allen! I get it! I've read enough. And its a foggy rabbit hole. That's a great idea, unfortunately we had to button it up and store yesterday as we live in north country. However, I can tell you we have very modest requirements. Best off the top: Fridge (AC) Laptop charger, misc lights at night, water pump, furnace ignition, possibly a low power electric space heater. I could come up with a reasonable estimate I believe.

Thanks again for your input!

[jackbefus]

Have a read of the .pdf file in post 1 in this thread Presentation Materials for Solar-101 Discussion at the 2019 Elkhart National Rally - Grand Design Owners Forums (gdrvowners.com)

Brian

I have it and will go through it carefully! Thanks so much, Brian!!

[jackbefus]

jackbefus -- a fantastic primer is Will Prowse's Mobile Power Made Easy. Worth every penny to understand before spending money or attempting to design a system. (I read it multiple times when I was in your place.) https://www.amazon.com/Mobile-Solar-.../dp/B09GCPB8Q8



Howard

Exactly what I was looking for! Ordered! Thanks so much!

Jack

[jackbefus]

jackbefus -- a fantastic primer is Will Prowse's Mobile Power Made Easy. Worth every penny to understand before spending money or attempting to design a system. (I read it multiple times when I was in your place.) https://www.amazon.com/Mobile-Solar-.../dp/B09GCPB8Q8



Howard

Thanks for the reference! I will read that. Just what I was looking for.

[acoleman43]

Thanks very much for the graphic, Allen! I get it! I've read enough. And its a foggy rabbit hole. That's a great idea, unfortunately we had to button it up and store yesterday as we live in north country. However, I can tell you we have very modest requirements. Best off the top: Fridge (AC) Laptop charger, misc lights at night, water pump, furnace ignition, possibly a low power electric space heater. I could come up with a reasonable estimate I believe.

Thanks again for your input!

That's a great start. When we did our energy audit, we came up with about 3KW per day. This included use of microwave in the mornings, charging phones/laptops, lights, water pump, fridge (we have a 12V which...you can run yours on propane which uses very little energy), miscellaneous things. Because I wanted a 3 day supply of energy, our battery bank requirement was 9KWH. That is 7.5 100AH 12v batteries. Yikes. You will be surprised at how quickly the energy usage adds up.

Since our solar install there is one miscellaneous item I did not consider, the energy to run the electrical system (inverter, solar charge controllers, etc.). During the night we run fridge, 4 fans, charge phones and some laptops. We use approximately 2KWH of energy just during the night while we are all sleeping.

Our battery bank is the equivalent of 8 100ah 12v batteries (10.2KWH), yet we relied HEAVILY on our generator during a trip back east this past spring. The lesson I learned is that you can have all the solar in the world.....but if you don't have sun, it won't do anything for you. I would keep in mind there will be times your panels will not get the sun they need to keep the batteries topped off. Have a backup ready.

[TucsonJim]

jackbefus - When you analyze and design your system, don't hesitate to run your logic and schematics by us for confirmation or questions. We'll be happy to help. I'm going through my third solar and off grid design right now. I'm really going all out on this one since this will probably be our last RV (Yeah right...).

On our Reflection that we just sold, my average consumption was 130 amp hours (1,560 watt hours) per day. I'd equipped it with 800 watts of solar and three Battle Born 100 aH batteries. So theoretically, I had enough battery power to run the RV for two days even if we couldn't recharge with solar due to clouds.

On our new Solitude, I've already purchased four Li Time (Formerly Ampere Time) LiFePO4 batteries which will provide 920 amp hours or approximately 11,000 watt hours. My goal is to be able to run an AC for an hour or two if needed. I'm waiting for the RV to be delivered to determine how much solar I can put on the roof. I'd love to get at least 1,600 watts of solar, and more if possible.

[jackbefus]

That's a great start. When we did our energy audit, we came up with about 3KW per day. This included use of microwave in the mornings, charging phones/laptops, lights, water pump, fridge (we have a 12V which...you can run yours on propane which uses very little energy), miscellaneous things. Because I wanted a 3 day supply of energy, our battery bank requirement was 9KWH. That is 7.5 100AH 12v batteries. Yikes. You will be surprised at how quickly the energy usage adds up.

Since our solar install there is one miscellaneous item I did not consider, the energy to run the electrical system (inverter, solar charge controllers, etc.). During the night we run fridge, 4 fans, charge phones and some laptops. We use approximately 2KWH of energy just during the night while we are all sleeping.

Our battery bank is the equivalent of 8 100ah 12v batteries (10.2KWH), yet we relied HEAVILY on our generator during a trip back east this past spring. The lesson I learned is that you can have all the solar in the world.....but if you don't have sun, it won't do anything for you. I would keep in mind there will be times your panels will not get the sun they need to keep the batteries topped off. Have a backup ready.

Thanks for the added info. Appreciate the real world experience.

[jackbefus]

jackbefus - When you analyze and design your system, don't hesitate to run your logic and schematics by us for confirmation or questions. We'll be happy to help. I'm going through my third solar and off grid design right now. I'm really going all out on this one since this will probably be our last RV (Yeah right...).

On our Reflection that we just sold, my average consumption was 130 amp hours (1,560 watt hours) per day. I'd equipped it with 800 watts of solar and three Battle Born 100 aH batteries. So theoretically, I had enough battery power to run the RV for two days even if we couldn't recharge with solar due to clouds.

On our new Solitude, I've already purchased four Li Time (Formerly Ampere Time) LiFePO4 batteries which will provide 920 amp hours or approximately 11,000 watt hours. My goal is to be able to run an AC for an hour or two if needed. I'm waiting for the RV to be delivered to determine how much solar I can put on the roof. I'd love to get at least 1,600 watts of solar, and more if possible.

Thanks so much for your kind offer to review my plan, and I will do that! That's so helpful. Very good info!

Jack

[acoleman43]

jackbefus - When you analyze and design your system, don't hesitate to run your logic and schematics by us for confirmation or questions. We'll be happy to help. I'm going through my third solar and off grid design right now. I'm really going all out on this one since this will probably be our last RV (Yeah right...).

On our Reflection that we just sold, my average consumption was 130 amp hours (1,560 watt hours) per day. I'd equipped it with 800 watts of solar and three Battle Born 100 aH batteries. So theoretically, I had enough battery power to run the RV for two days even if we couldn't recharge with solar due to clouds.

On our new Solitude, I've already purchased four Li Time (Formerly Ampere Time) LiFePO4 batteries which will provide 920 amp hours or approximately 11,000 watt hours. My goal is to be able to run an AC for an hour or two if needed. I'm waiting for the RV to be delivered to determine how much solar I can put on the roof. I'd love to get at least 1,600 watts of solar, and more if possible.

I have 1260W on a little 21G and could have added 2 more 210W panels for about 1700W. I'm sure you can fit 1600W on a larger Solitude

With 10.2KWH of batteries and 1260W solar I can run my air conditioner for a few hours a day if I have full sun.....although I have just 1 AC.

[50ST8R]

All great ideas ahead of me. One other thing to consider as you start considering components, cablings, fuses and switches, "if I decide to go bigger what will I need to purchase again to accommodate?" For instance, Although there are good small capability solar controllers, if there is ever a possibility of adding more solar, starting with a bigger controller and possibly large gauge wire might be a good consideration. We bought a Victron 150/100 controller knowing that I might want to add additional panels. (doing that this winter) don't forget to estimate power requirements a bit more than you expect because "if you build they will come" mentality once you have you use it more and have greater need. Good luck pulling things together and share your ideas. We all get smarter as the threads increase.

[jackbefus]

All great ideas ahead of me. One other thing to consider as you start considering components, cablings, fuses and switches, "if I decide to go bigger what will I need to purchase again to accommodate?" For instance, Although there are good small capability solar controllers, if there is ever a possibility of adding more solar, starting with a bigger controller and possibly large gauge wire might be a good consideration. We bought a Victron 150/100 controller knowing that I might want to add additional panels. (doing that this winter) don't forget to estimate power requirements a bit more than you expect because "if you build they will come" mentality once you have you use it more and have greater need. Good luck pulling things together and share your ideas. We all get smarter as the threads increase.

Good thoughts, Kevin. I will do that. I ordered a book someone recommended and look forward to learning from that. Will keep anyone interested updated on thoughts.