Solar Power: Myth?

[lewster]

Originally Posted by GMFL

Solar is definitely not a MYTH if installed correctly.

Absolutely agree!!

I have been installing solar on mostly Airstream units for the last 10 years and my systems WORK and work well. Everyone that has one loves the convenience and power they provide.

[SilverWind]

We traveled to Alaska in 2016. On the road for four months, 85% dry camping. Never even put gas in the generator. 350watts of solar on the roof of our 23FB. We felt very warm and fuzzy like good liberal campers.

Our current 25FB has 500 watts of 100 watt panels with two AGM batteries, all installed by AM Solar in Springfield, OR. Still haven't put fuel in the generator.

[AdvToaster]

Originally Posted by ASFC25_2019

That is an amazing set up. What size of A/C unit do you run? And how long can it run for on battery power no solar. How many Ah do you normally get each day?

I usually run the rear 13.5k AC while we’re driving. I couldn’t tell you how long it runs without solar or any external power coming in, but today my DCDC charger didn’t run while we drove, so we did 7h50m with just the solar adding 1.85kW. Outside temp was around 96, no clouds, and the AC was set to 80. We had 5% battery left when we plugged in.

[stevejones]

Originally Posted by lewster

Absolutely agree!!

I have been installing solar on mostly Airstream units for the last 10 years and my systems WORK and work well. Everyone that has one loves the convenience and power they provide.

Lew installed our system and it works great. Very clean, professional install. I love not having to worry about power!

Steve

[SpinWhite]

We carry carry a portable 200 watt suite case for our 23FB. I am a novice about solar costs. What is a appropriate cost of the system would be to run AC on our AS?

[Hans627]

Originally Posted by SpinWhite

We carry carry a portable 200 watt suite case for our 23FB. I am a novice about solar costs. What is a appropriate cost of the system would be to run AC on our AS?

Curious about the answer to this question.

Thx

[DaveP]

Originally Posted by SpinWhite

We carry carry a portable 200 watt suite case for our 23FB. I am a novice about solar costs. What is a appropriate cost of the system would be to run AC on our AS?

Well, from what I have seen on these forums and from my install, you would need (in round numbers):

- at least 400 watts of solar $400+
- at least a 100/30 MPPT solar controller $200+
- at least 400 Amp Hours of lithium battery $4000+
- a 3000 watt inverter/charger $2000
- Miscellaneous wire, terminals, fuses, switches, etc. $500+
- crimping tools
- do the work your self

I am probably missing something, but say $7100+ in total.

Good luck!

[LilPeanut]

Will you save money in the long run? Probably not. But I didn't get a camper to save money, I got it for experiences. It does change the experiences you can have. You can stay at a Harvest Host more confidently, boondock and worry about grey water a lot more than power. Take a 15 min nap at a rest area with the AC running in the middle of a long driving day. It does change the experience. Is it worth it? That's up to you to the individual to decide. Would you get it as an upgrade when purchasing new if offered?

Lewster installed mine. 1000W of solar on the roof and 600ah of lithium. I have a big rig - 30'classic so it has lots of room. It did change what we can do with confidence and a good margin for error. Also, I now never plug it in when it is outside for a day or two getting ready for a trip. I used to pull out the cords because there wasn't enough power in the two AGM batteries to keep it going with confidence.

[gator.bigfoot]

Originally Posted by DaveP

Well, from what I have seen on these forums and from my install, you would need (in round numbers):

- at least 400 watts of solar $400+
- at least a 100/30 MPPT solar controller $200+
- at least 400 Amp Hours of lithium battery $4000+
- a 3000 watt inverter/charger $2000
- Miscellaneous wire, terminals, fuses, switches, etc. $500+
- crimping tools
- do the work your self

I am probably missing something, but say $7100+ in total.

Good luck!

I put in AGM and 300 watts. Total around $2200. A lot cheaper than what you're quoting. Still gets me off grid indefinitely and let's me enjoy those experiences. If you need a microwave and blow dryer and AC stay home or find an electrical site.

[DaveP]

Originally Posted by gator.bigfoot

I put in AGM and 300 watts. Total around $2200. A lot cheaper than what you're quoting. Still gets me off grid indefinitely and let's me enjoy those experiences. If you need a microwave and blow dryer and AC stay home or find an electrical site.

Hi gator,

The question from spinwhite was, how much would it cost to put in a system that will run the AC in the trailer. Hence, my answer covered that.

Cheers,

[SpinWhite]

Thanks DaveP, LilPeanut and gator.bigfoot. Now I have numbers to overcome the “Myth”.

[DaveP]

You are welcome, spinwhite. I see you live in Texas. The cheaper thing to do is put in a decent solar charging system with AGM batteries, no inverter and take a generator with you to run the AC. That's what I do when I think I am going to run the AC.

Cheers,

[gator.bigfoot]

Originally Posted by DaveP

Hi gator,

The question from spinwhite was, how much would it cost to put in a system that will run the AC in the trailer. Hence, my answer covered that.

Cheers,

I'd be interested in seeing how long the AC will run on your system. And the how long before it recharges.

[wulfraat]

Originally Posted by gator.bigfoot;

I'd be interested in seeing how long the AC will run on your system. And the how long before it recharges.

About 2 hours on 400ah of lithium depending how hot it is / compressor cycling and system pressure.

[DaveP]

Originally Posted by gator.bigfoot

I'd be interested in seeing how long the AC will run on your system. And the how long before it recharges.

What wulfraat said... (and he has that system)!!

[gator.bigfoot]

Originally Posted by wulfraat

About 2 hours on 400ah of lithium depending how hot it is / compressor cycling and system pressure.

What is battery level at the end of 2 hours? How long to recharge on solar assuming full sunshine?

[wulfraat]

Originally Posted by gator.bigfoot

What is battery level at the end of 2 hours? How long to recharge on solar assuming full sunshine?

After ~2 hours with 400ah of batts you’re at 20-25% ish SOC. BMS will cut off the batts and they go dark at 20%.

Assuming full sunshine 400watts of solar (laying flat/not tilted) will put back about 125-140ah per day in June / July. So it would take 2 days and a bit to replenish 360ah used to run 1800-2000w draw for ~2 - 2.5hrs assuming you are producing solar energy on the day you are running the aircon.

You have to remember that the inverter is only 90(ish) percent efficient and there are inherently a few other items drawing from the batteries throughout the day and night - you cannot just got off the AirCon load.

You should size your solar to put back about 50% of your battery bank per day. For instance I have 800w and 600ah of batts (480ah usable) and I have found this to be a nice mix. When “camping” I run everything in “residential mode” and I run through 150-200ah per day. My solar panels will put back about 250-275ah of energy back per day.

I have a victron multi which has hybrid operation. If I need to run the aircon for a long time I’ll use my little honda 2000 on propane to supplement the batts with another 1200 watts or so (I tend to camp at altitude at or above 7,000ft, which cuts down on generator output). This really takes the edge of drawing down the batts.

Solar is a good thing.

[Jim J]

My problem is cost per watt. The first 200 watts of permanently mounted ( on an Airstream roof) solar power are outrageously expensive, cost comes down quite a bit if you double that, but still very high. If you have room for 600 watts it gets better. Then if you want to optimize your battery situation to lithium you have even more expense.

Before I abandon my generator I am going to try some portable panels, probably home made, with a low cost pulse width modulated controller and my old flooded lead acid batteries. I think I can put all this together for under $2 per watt. For a 200 watt system.

I am currently using a small 15 w panel and Morningstar pwm controller for maintenance charging while parked which is keeping my 7 yr old Interstate batteries in great shape.

[wulfraat]

My “all in” system cost is a little over $23/watt and that’s after a 30% solar tax credit for renewable energy system install. This includes lithium storage of course.

It is a massive investment and the ROI cannot be measured in dollars. Kinda like the airstream itself.

Residential / commercial grid tie solar generation systems are a different matter altogether of course, both in terms of cost per watt and measurable payback period. (IE they can pay themselves back over a period of 7-15 years typically).

[JMynes]

Wow. A guy with one post (still only one) starts a poll asking if solar is a myth and it drifts into running your AC using only sunshine as fuel.