All solar

[lesliegarner]

has anyone ever used solar to power entire system - AC, heating, appliances, lights, etc? Have gutted 73 Overlander and wondering if you can get by w/o propane.

[lewster]

Originally Posted by lesliegarner

has anyone ever used solar to power entire system - AC, heating, appliances, lights, etc? Have gutted 73 Overlander and wondering if you can get by w/o propane.

Sure you can!!!

Just depends on how many batteries (hopefully lithium) you intend to carry, how many solar panels you can fit on your roof and how deep your pockets are.....

Look up a member on the Forums 'Beach Bum' and send them a PM. They have a substantial solar array (800 watts), large lithium pack (600-800 amp/hours) and have removed most if not all LP devices. marine fridge, infrared cook top, etc.

[polarlyse]

Last Oct. at a Rally in South Carolina I met a guy that had a solar system that he claims can run his AC for 5 hours on Battery. I suspect lithium (but don't know for sure) and I think he said 800w of solar panels. He even had a dishwasher. So like Lew said, it can be done but be prepared to part with some $$$$.

[uncle_bob]

Hi

Ok, so rather than tossing around "I heard this" let's run the numbers:

If you have a large trailer, you will run two AC units. If it's really hot out, they will *both* run quite a bit. If you want to do that on top of "everything else" you need a lot of current.

Let's say you need to run 50A at 120V. That's about 1/2 what a big trailer with everything turned on will run (it runs 50A at 240V). At 12V, that will be 500A. Unless you really like buying new batteries, you will need at least 1000AH on your battery stack. (discharge at C/2 rate). You also will need at least a 6KW inverter.

How much of the time do you pull 50A? Certainly not all the time. Let's guess that it's about 30% of the time. Put another way, during the day, you average 150A. That either comes off your solar (is it cloudy?) or batteries. Normally you design for 24 hours on batteries. So 8 hours at 150A gives you 1200 AH.

Let's say that the 4 hours in the morning and 4 hours in the evening are at 1/2 that rate. It's a guess, but probably not over the top. That gets you 600 AH. For the overnight period, we'll go with 300 AH. Net is 2100 AH of battery. That's 25.2 KWh.

You need to be able to charge 2100 AH in the average 8 hours of "peak solar". Yes you get power over a longer period than that. You also don't hit peak for the whole 8 hours. You will need a bit over 3KW of solar on the roof.

No, we haven't figured in efficiencies. There is no margin in these numbers. It's at best powering things for a fairly small trailer or under not so crazy conditions. If you want to do a 33' in the Arizona sun or the Houston swamp, you would at least double the numbers above. Put some margin in and you would boost them still more.

So, can you do it? Of course you can. It's only money.

Should you do it? Did you have any other plans for all that weight and all that trailer volume? (or all that money).

Can you do a "bragging rights" version for less? Of course you can. Put in a 4,000 BTU AC instead of a 13,500 or a 15,000. Turn everything off for 80% of the time. Run the AC for one hour at 10 PM to 11 PM. You now have bragging rights. It's not clear you have much more than that.

Bob

[Beach Bum]

Originally Posted by lewster

Sure you can!!!

Just depends on how many batteries (hopefully lithium) you intend to carry, how many solar panels you can fit on your roof and how deep your pockets are.....

Look up a member on the Forums 'Beach Bum' and send them a PM. They have a substantial solar array (800 watts), large lithium pack (600-800 amp/hours) and have removed most if not all LP devices. marine fridge, infrared cook top, etc.

That would be me.

It can be done with standard off the shelf products and some trade-offs if you add a solar system with the right design. Three things that propane excels at with no shore power are cooking, hot water and heating. Refrigerator is not a problem using a marine fridge and a well designed solar system. Cooking can be done using an induction burner or microwave on an inverter for short durations. So, If you are willing to take cold showers and use lots of layers for heat or add a generator to the system then yes is the answer. There are tradeoffs with any combination of solar, generator, propane power systems you choose to use.

I am a solar user but would not go all electric too many tradeoffs for me. Total Solar system supporting AC, heat and hot water would probably require the use of a generator or very large battery bank and roof and portable solar panels as well.


Our solar story and system

With that said we have a 30’ FC and moved toward a mostly electric w/solar set up. I replaced the dometic fridge with a 120/12 v marine fridge and the propane stove with a two burner induction cook top. Which we love. No plans to replace either propane hot water heater they consume too much electricity to make them viable when dry camping unless you added a generator to the mix. Tradeoff we don’t run our AC when dry camping and use a two burner outdoor propane camp stove for extended cooking when needed. On the flip side if there is 15 amp service at the site with our hybrid inverter we are golden. We do not have or plan to purchase generator for back up. We have found that with a little planning and some energy conservation in less than optimal conditions (weather and shade) we have no issues.



Two summers ago summer we went 11 and 16 consecutive days at primitive sites with no hook ups using our 7.1 cu ft marine AC/DC refrigerator/freezer with no problems.

After 3 nights of marginal weather and a mostly shady site at the north rim of the Grand Canyon, we were running a little low on juice 193 amp draw down on the AGM batteries could have stretched it one more night if we had to. We learned to limit our energy consumption when camped in crappy weather or shady sites for more than a day or two.



Last year we upgraded to lithium batteries and the hybrid inverter so we could use the induction cooktop, microwave, when dry camping and have and have all the creature comforts needing only 15amp service.

Our initial, AM solar set up was 540 watts on the roof, 1000 watt inverter and 600Ah of AGM batteries under the couch. This was an expensive learning experience as we upgraded to AM solar 3000 Watt hybrid inverter with 740 watts on the roof and 600 AH lithium batteries which better suits our needs.


With the upgrade we can dry camp and use the induction cooktop, microwave and other electric gadgets. The system is designed for a minimum of 4 days with crappy solar conditions. In the good solar conditions we are self-sufficient, water and holding tank capacity are the limiting factor. Our propane usage is minimal as its primarily for hot water showers and dishwashing I think we used one tank in two years. Yes we are glampers but we do not want a generator and we like to camp in places that don’t have hook ups. We don’t use AC when dry camping. Not for everyone it’s Just the way we roll.

A properly designed solar vs generator vs propane vs electric set up is a matter of personal choice, no right or wrong answer. Do what best suits you, your pocketbook and your camping style. IMHO the most important things to understand before designing your system are your electrical needs, how you like to camp, and what tradeoffs you are willing to make.

PM me if you want more info about our experience with our electrical and solar setup.

[Troutboy]

I have 500w, 320amp hour lithium, on a hot sunny day, I ran a single smaller AC (13500) for nearly 6 hours (on/off) to keep temp at 70. Drained battery from 100% to 26%, and that's with full on clear day Colorado sun putting power back into batteries while AC ran. I think you would need at least 600-800 amp hours of lithium to attempt this, and you would be looking at over $15k-20K in system costs, if you did it your self! Seems cost prohibitive, unless you have endless amounts of cash....

[uncle_bob]

Hi

One thing you have in your favor "out west" is that the AC generally does not have to deal with a lot of humidity. Yes, I have been to the Pacific Northwest and noted the "humidity". I also don't recall needing much AC up there Rain wear every day yes, AC ... no.

Bob

[Monza]

Anyone have some quick links to getting schooled on lithium batteries and solar setups in an RV.
I have a full Monty on a 72' Tradewind underway I'm searching every system and my head is spinning...

[Troutboy]

Originally Posted by Monza

Anyone have some quick links to getting schooled on lithium batteries and solar setups in an RV.

I have a full Monty on a 72' Tradewind underway I'm searching every system and my head is spinning...

Go to the am solar website, great RV solar tutorials and learning. Here is a link to their discussion on batteries and lithium

http://amsolar.com/diy-rv-solar-inst...s/edbatteries/

[AnnArborBob]

Aside from the size and cost of the LiFePO battery bank you'd need to run the AC for any length of time (the batteries and inverter to do this for several hours would likely cost nearly $10,000) the real "deal killer" to getting rid of the propane entirely as far as I'm concerned would be heating the trailer. Trying to heat an Airstream with electric rather than propane would take even more battery capacity than running the AC.

[Monza]

Originally Posted by Troutboy

Go to the am solar website, great RV solar tutorials and learning. Here is a link to their discussion on batteries and lithium

http://amsolar.com/diy-rv-solar-inst...s/edbatteries/

Thanks for that. WOW lithium batteries ae serious $$.

[Troutboy]

Lithium batteries will be, if you use them, 50% of the cost of the system.

My initial estimate for my 500W system was around $4K for the materials (solar panels, charger, inverter/charger) etc. and 440amp hours of AGM.

When I switched to lithium, cost went to $8000.

Note smaller inverter system I designed would have given 500W for around $3k, all in.

These prices are for parts only. I did labor on my own.

So yes, lithium is very expensive initially. I switched to lithium mainly for the weight benefit as I was limited in my payload, and the optimized charge cycles.

[uncle_bob]

Originally Posted by Monza

Thanks for that. WOW lithium batteries ae serious $$.

Hi

Resist the urge to go for cheap "no name" lithiums ....You might get good ones, you might get a ball of fire. How lucky do you feel?

====

Just curious: What do you plan to tow your 72 foot long TT with?

Bob

[Monza]

[QUOTE=uncle_bob;1970625]Hi

Resist the urge to go for cheap "no name" lithiums ....You might get good ones, you might get a ball of fire. How lucky do you feel?

====

Just curious: What do you plan to tow your 72 foot long TT with?

Bob[/QUOTE

Yes, thanks for that advice. Buy once cry once, I think I'm going with regular batteries for now, do more research and figure out what I really need. Maybe prices will keep dropping in that time.

------
I tow the 72' footer with a semi.

[Troutboy]

If you can, go with AGM batteries. They cost more than standard wet cell lead acid, but last linger, charge faster, and are just about making free

[GMFL]

Rich,
Where did your panels come from
Thanks
Ronnie

[Troutboy]

Am solar Ronnie. I got everything From them. That way they helped a ton with install and customer service. I like the smaller panels. Renogy may make a similar one, maybe source it cheaper?

[Monza]

Originally Posted by uncle_bob

Hi

Resist the urge to go for cheap "no name" lithiums ....You might get good ones, you might get a ball of fire. How lucky do you feel?

====

Just curious: What do you plan to tow your 72 foot long TT with?

Bob

So do these fit in your category of cheap 'no name'?
It's hard to find much bad on them? Less expensive but I don't know if it call them cheap. But I'm 20.00 red wine budget guy. That's a 10.00 bottle in America...

https://battlebornbatteries.com/shop...cycle-battery/

https://battlebornbatteries.com/shop...erter-charger/

[Monza]

Originally Posted by Troutboy

Go to the am solar website, great RV solar tutorials and learning. Here is a link to their discussion on batteries and lithium

http://amsolar.com/diy-rv-solar-inst...s/edbatteries/

Finally spent some time reading this whole site, these products look great.
Thanks again.

Here is where I'm at on my build:
http://www.airforums.com/forums/f125...ty-169494.html

[uncle_bob]

[QUOTE=Monza;1970659]

Originally Posted by uncle_bob

Hi

.....
I tow the 72' footer with a semi.

Hi

So you are up around 95' overall maybe? .... yikes !!

Bob