Solar vs generator

[charbert69]

I have just bought a 2018 DRV elite suite Nashville 5th wheel. We are going full time and planning to do lots of Boondocking. Our trailer has no generator. I have a appointment to have a onan/Cummins 5500 installed in May. But been reading about solar. So what I would like to know is the pro and con for solar. Generator cost is 10500 installed the trailer all ready has a 3000 watt investor/charger.

[Cooperhawk]

Well, by boon docking what do you mean? Do you want AC? Do you want unlimited TV? Just what are your needs going to be.
If you want all that solar will help, but won't support those amenities. If it were me I'd get the genset and use it when needed.

[charbert69]

I want to to use on a/c and run refrig, tv, lights and 1 out of 3 a/c units. The solar I was looking into was 4-200 watt panels and 4-lithium batteries then have a small 2500 watt generator for when no sun to charge batteries as a backup.

[Nwcid]

Solar is not a replacement for a generator, and a generator is not a replacement for solar, at least not yet. Generator is the most cost effect way to run large power consumption items, but they are noisy and take fuel.

Solar is quit, nice, convenient and "eco-friendly", plus it makes no noise. Up front cost vs power output is the biggest challenge.

I have a medium size (~55 amps) solar system on my RV but I would not be without a generator that can run my systems. I would say I use solar over 90% of the time, but that other 10% I am glad I have a generator. Last trip out in 3 days I put over 36 hours on my generator.

It is a math problem.

How much total draw (amps out) do you want to use, for how long (amp hours) and how long to you want to take to recharge it (amps in)?

For every 100 watts of solar you get about 5 amps of charging at peak performance. Depend on your location and time of year that can be between about 4 and 8 hours.

So 800 watts divided by 5 amps/100 watts = 40 amps of charging, again at peak.
You say 4 lithium batteries since the most common off the shelf is 100 AH, we will say you have 400 AH of storage.

TV, lights, fridge, "daily items" will typically draw around 15-20 amps so lets call it 20 to be safe. With 400 AH / 20 amps you could run for 20 hours with no charging.

A single air conditioner will draw around 130 amps. 400 AH / 130 amps you will get about 2 hours with no charing. Even with your solar at peak contributing 40 amps you are sill drawing 90 amps. So 400 AH / 90 amps gets you almost 4 hours of run time.

Now to do the math the other way. Lets say overnight you use 200 AH, or 1/2 of your batteries. Now you need to charge them back up. At peak of 40 amps it will take 5 hours (with no other draw) to get your batteries back to full.

[Freqz]

Running an AC on solar is a HUGE ask. There just isn’t enough real estate on the roof even for a large fifth wheel. Then you have to buy the batteries...

I look at batteries/solar as allowing me to not only minimize gen time but also to shift it to when it’s more convenient/less obnoxious. I have a somewhat large system— 1000W solar with 10kWhr of lithium (420 Amp hours@24V), and I can’t use the AC for than a few of hours without plugging in somehow if I’ll want to do the same thing tomorrow.

Really, a smaller gen with more solar/batteries is the most useful within a reasonable budget, IMO. $1000 on, say, a Champion 3k gen then $9k on solar/batteries is a much more broadly usable system that won’t require constant gen time unless it’s quite warm out. For modest temps, you wouldn’t even need to drag it out . How rarely you need to get it out depends on many panels you can shoehorn on the roof and how many batteries your budget will allow

[Lantley]

Honestly f I were in it for the long haul I thing I'd do both. But Maybe I would get a smaller genset and invest more in a solar. Solar is the wave of the future. Before I install that 10K genset. I would have a long talk with a solar specialist.
Running A/C via solar was once thought to be impossible however now it is quite possible to do it for a few hours a day with a modern (state of the art) solar set up.
If you are full timing a few hours a day of A/C will not be sufficient and a large genset will still be required.
However how often will you need A/C? Will a much cheaper portable genset be adequate for those times? The solar vs. Genset question continues to evolve right now I think the answer is skewed more towards solar than ever.

[paul65k]

Originally Posted by Freqz

Running an AC on solar is a HUGE ask. There just isn’t enough real estate on the roof even for a large fifth wheel. Then you have to buy the batteries...

I look at batteries/solar as allowing me to not only minimize gen time but also to shift it to when it’s more convenient/less obnoxious. I have a somewhat large system— 1000W solar with 10kWhr of lithium (420 Amp hours@24V), and I can’t use the AC for than a few of hours without plugging in somehow if I’ll want to do the same thing tomorrow.

Really, a smaller gen with more solar/batteries is the most useful within a reasonable budget, IMO. $1000 on, say, a Champion 3k gen then $9k on solar/batteries is a much more broadly usable system that won’t require constant gen time unless it’s quite warm out. For modest temps, you wouldn’t even need to drag it out . How rarely you need to get it out depends on many panels you can shoehorn on the roof and how many batteries your budget will allow

This is some of the best advice you'll get right here ^^^^

I have almost exactly the same set-up and even though I have a little more solar this is exactly spot on when making your decision.

It's different all the time......last summer we went almost 10 full days without using the generator once, including an hour or two every day with one AC going, this winter I was only able to go 3 days without the generator (Cloudy and rain) and I didn't run either the AC or the propane heater.....so it all depends!

[deblas]

As we boondock 100% of the time (recreationally), there is no way I’d be without a generator intentionally. IMHO, you would quickly regret not having the generator.

I would consider the initial upgrade with the generator then build the solar over time, presuming cost is a factor.

There are no time limitations for running the generator that I am aware of while boondocking unless you’re boondocking in a park?

[SV K]

Hi Chartbert69,

I may have missed this in the thread, but do you camp in the sun or in shade for most of the day?

For example here at Q I have only needed to run my genny for 5 hours in the last 3 months. If I was camping in the trees (well not here as there aren't any) I’d need to run it everyday for a little while.

One little benefit that surprised me is that the big solar arrays on the roof do help to keep the coach cooler. Not like AC of course.

[wildtoad]

The manufacturer installed (or you requested) 3 AC units to cool your extra large fiver. Where do you plan on boon dock camping where you think one will do? Here in the south, where sometimes it stays in the low 80’s at night you will want more.

Solar is nice to have and will reduce your dependance on a generator. Just make sure you are sure about your needs.

[Mark_K5LXP]

To state the obvious, solar panels work in sunlight. Which means you're parking your RV in the sun. Along with whatever wattage you get from the panels you're also heating up your RV. This is a win-win in cold weather but if you have to run your A/C to keep it tolerable in the summer you're going to be burning more watts running the A/C than you'll ever generate with panels. So you end up running the genset, defeating the purpose of having solar. If you can park in the shade, you may not need A/C, or as much. Solar can work depending on how you use it, but it does require some accommodation.

Mark B.
Albuquerque, NM

[Cassy]

Originally Posted by charbert69

I want to to use on a/c and run refrig, tv, lights and 1 out of 3 a/c units. The solar I was looking into was 4-200 watt panels and 4-lithium batteries then have a small 2500 watt generator for when no sun to charge batteries as a backup.

Excellent combination!!! Generator more of a summer thing or a few days of rain.

[jacknife]

Originally Posted by charbert69

I have just bought a 2018 DRV elite suite Nashville 5th wheel. We are going full time and planning to do lots of Boondocking. Our trailer has no generator. I have a appointment to have a onan/Cummins 5500 installed in May. But been reading about solar. So what I would like to know is the pro and con for solar. Generator cost is 10500 installed the trailer all ready has a 3000 watt investor/charger.

That’s

[jacknife]

Go to Norwalk power free shipping 5500 Oman $4300 . Install should be no more than a grand if your trailer is gen prepped . I bought mine from them and had about 5500 invested in the whole thing . They are ripping you off . Gen prep should be no more than an additional grand .