Looking for Solar Advice

[LucasEbert]

Hey guys,

Im new to the forum, so forgive me if I am asking a common question here..

I just bought a bus and I am looking for some advice as to what solar system to go with(or if I should go solar at all?) ..

My needs are VERY minimal. the only things Ill need electricity for are:

1. Energy Efficient RV refrigerator

2. An AC/Heater unit (one like you typically see mounted on the ceilings of most RV's)

and, 3. Charging Cell Phones and Laptops


THAT'S IT!

I wont be wiring lights because I am keeping things as simple as possible. I decided to go with LED tap lights i found at a hardware store.

I am looking for the most straightforward and easy to solar system that I could possibly go with while at the same time not having to worry about energy consumption.

I was told I could possibly even just use the buses battery and forgo solar altogether.

I don't understand electricity (and don't really care to). I'm just looking for the quickest and easiest solution for my energy needs.

Any advice is greatly appreciated!

Thanks!

-Lucas

[lucasd]

Originally Posted by LucasEbert

I don't understand electricity (and don't really care to). I'm just looking for the quickest and easiest solution for my energy needs.

If you don't want to take the time to gain a thorough understanding of the systems involved, your only quick and easy solution is going to be taking your rig to a professional and paying to have a system put in.

I will also note that your list of minimal requirements involves heat/AC. You are unlikely to find an off the shelf mobile system that is able to run an AC or heater for any length of time. Refrigerators, lights, and laptops are fine, but when you get into heating and cooling your living space, you are in a whole new class of power consumption.

It's probably not impossible to build a system capable of running an AC, just as very few things are flat out impossible, but it would be very expensive. Mobile AC systems typically draw so much power that your only realistic approach is to run one from a generator. Designing a pure solar approach to powering high loads like this is definitely not something you want to do unless you are prepared for the expense and a lot of time spent learning the technology.

[heathnlaura]

I would agree. That's a lot like saying my only needs for gasoline are my 1.5 hp lawn mower, my little weed wacker, and my 67 Camaro with a 502 big block that turns 10 second quarter miles.....that's all.

The solar will act more as generator than battery charger. If you need to crank out 1500 watts for the A/C unit you'll might as well to 2k watts as you'll want to put a little back into your batteries. Any battery bank you wanted to use the run the A/C even for just a couple hours would take up quite a bit of room. The upside it paying for that battery bank would clear up a lot of room in your wallet.

A good resource would be Handy Bob.

He's never short of words.

https://handybobsolar.wordpress.com/

[PNW_Steve]

Along with "heat & AC" you have an "energy efficient RV refrigerator" listed.

If you are considering a typical RV refrigerator take a look at their actual power consumption when running on electricity. If you run it on propane you will, obviously, use considerably less electricity but now your propane supply is going to take a hit.

I replaced an older 6.8 cu. ft. RV refrigerator with a new 10.8 cu. ft. apartment refrigerator two years ago. I measured power consumption on both with a kill-a-watt meter. Over 30 days the new fridge used 1/2 the power that the RV fridge did.

The Handy Bob Solar blog is full of good information. Also, to get a good handle on realistic loads and system sizing, take a look at the calculator and other info here: https://www.wholesalesolar.com/solar...rid-calculator

Myself, I am planning on 1200-1500 watts of solar installed as well as a 3-6kw generator.

[TAOLIK]

Originally Posted by LucasEbert

Hey guys,

My needs are VERY minimal. the only things Ill need electricity for are:

1. Energy Efficient RV refrigerator

2. An AC/Heater unit (one like you typically see mounted on the ceilings of most RV's)

and, 3. Charging Cell Phones and Laptops

Hi, I'm probably not qualified to give you advice, but I'm going to anyway.

You, yourself probably have simple needs, but AC/Heater is NOT a minimal electrical need. That's like asking you to help me move a nonfunctioning forklift into my truck and calling it a "minimal request".

If you really want to do solar, as everyone else has stated you should read Handy Bob Solar's RV battery charging puzzle. (this underlined stuff is a link), after you read that, you should probably read through it 1-2 more times over the next week.

Your simple needs suggest that you want to part time in your bus. If you want to do a simple minimal setup, ditch the rooftop AC, ditch the solar panels, buy a few 10-12 gauge extension cords, a free standing AC, and a 3-5k generator, and plug all that into your generator. If you do this, you can also probably get away without buying batteries immediately(though they are good to have).

If you really want to do solar, don't heat via electricity, it is inefficient. Heat via propane, wood, diesel, or something that is not electricity. Also, don't plan to run your AC off solar, plan to run your AC when you're plugged into a shore or a generator.

Energy Efficient Refridgerator: Look into a chest freezer conversion with a thermostat controller. If you want to go the easy route, there's a thermostat controller you(or a 4-year-old) can just plug into which will turn your freezer into an energy efficient refrigerator with custom temperature controls.

For your laptop and cellphones, charge through 12v via usb or car charger, that will lesson your dependence on your inverter.

[Iceni John]

As others have said, normally one cannot run A/C from solar. But that's assuming using the typical few hundred watts of solar (what most RVs and bus conversions have) and typical RV roof-top A/Cs. Now, if you can increase the amount of solar and decrease the A/C's power needs, there's no reason it can't work. Solar is cheap now, as cheap as it's ever been, and you can buy new grid-tie panels for well under a dollar a watt, sometimes even less than $0.50 a watt! At those prices it makes sense to carpet the roof with as much solar as you can afford, with the incidental side benefit that far less heat from the sun will then transfer through the roof to the bus's interior. Mini-split A/Cs are much more efficient than traditional RV units, especially if they're the inverter type with soft start. A 12k BTU inverter mini-split draws less than 10A, and most of the time much less than that. With sufficient solar for about 1000 Ah of 12V batteries you can easily run A/C during the day just off the solar, and for a few hours after the sun goes down before the batteries approach 50% SOC. And if you get mini-splits with integral heat pumps, you may be able to also heat in moderately cold conditions - clear winter days can produce the highest solar output, albeit for reduced hours each day, so heating isn't completely out of the question either.

I have 2kW of solar and will have about 900 Ah of batteries initially, and plan on buying one or two 12k mini-splits (the biggest 120V size), plus a small window unit just for the bedroom if I need to quickly cool it down before going to bed. The bedroom's A/C will nicely fit in the rear roof cap above the bed, and with some ingenuity I hope to fit the mini-split condensors under the floor somewhere (he says optimistically) if I can tilt them 45 degrees and reposition the compressor to keep it vertical.

Nothing's impossible!

John

[PNW_Steve]

An interesting alternative, 12 volt mini-split A/C.

28Amps @ 12 Volts for a 6000 Btu mini-split:

[Scott Marcano]

Originally Posted by Iceni John

As others have said, normally one cannot run A/C from solar. But that's assuming using the typical few hundred watts of solar (what most RVs and bus conversions have) and typical RV roof-top A/Cs. Now, if you can increase the amount of solar and decrease the A/C's power needs, there's no reason it can't work. Solar is cheap now, as cheap as it's ever been, and you can buy new grid-tie panels for well under a dollar a watt, sometimes even less than $0.50 a watt! At those prices it makes sense to carpet the roof with as much solar as you can afford, with the incidental side benefit that far less heat from the sun will then transfer through the roof to the bus's interior. Mini-split A/Cs are much more efficient than traditional RV units, especially if they're the inverter type with soft start. A 12k BTU inverter mini-split draws less than 10A, and most of the time much less than that. With sufficient solar for about 1000 Ah of 12V batteries you can easily run A/C during the day just off the solar, and for a few hours after the sun goes down before the batteries approach 50% SOC. And if you get mini-splits with integral heat pumps, you may be able to also heat in moderately cold conditions - clear winter days can produce the highest solar output, albeit for reduced hours each day, so heating isn't completely out of the question either.

I have 2kW of solar and will have about 900 Ah of batteries initially, and plan on buying one or two 12k mini-splits (the biggest 120V size), plus a small window unit just for the bedroom if I need to quickly cool it down before going to bed. The bedroom's A/C will nicely fit in the rear roof cap above the bed, and with some ingenuity I hope to fit the mini-split condensors under the floor somewhere (he says optimistically) if I can tilt them 45 degrees and reposition the compressor to keep it vertical.

Nothing's impossible!

John

let us know when you start that minisplit system, thinking about that myself.