Value of solar?

[Tablerocked]

I’m an electrical engineer and I’m having a hard time justifying the enormous cost of solar vs the fairly low power return, especially in my area where our camping will be in heavily wooded areas.

Am I nuts to take that money and add more Amphours to my lithium battery bank?

Does anyone have any real data showing use by type vs lithium capacity vs time?

I live in the Ozark mountains and plan to do a lot of camping nearby that has 30/50 amp hook ups.

[Bill M.]

If you are on hookups you do not need any additional battery capacity. Dollar for power I think a small generator is your cheapest and most reliable source of more boon docking time. I am going to assume you have the electric refrigerator? I would want at least 200 amp hours lithium and a generator.

[fran&frank]

It depnds on how you camp. We are usually at sites with no hookups so solar or/and a generator are essentail for us. If you have already invested in lithium batteries adding solar is relativley cheap, at as little as $100 a panel, especially if you can DIY. --Frank

[1StreamDream]

I agree, that it very much depends on your style of camping. You mention most of your time is spent with 30/50amp hookup, and in that case I don’t see the value of either one, solar OR lithium. I have been able to run my fridge(LP), and furnace, for 12+ hrs (overnight temps in the 40’s) with group24 wet cells. I do have 480w of solar on my roof, and another 140w of suitcase solar, but that is because I intend to spend significant time in national parks, or BLM boon docking (no electric hookups) and I prefer NOT to run a generator. I don’t have lithium yet, but that’s next on my list. I have a 2200w Honda, but it’s primarily a contingency plan, and an option in case it’s so hot I need some A/C (I also have a micro-air easy start on my A/C). Hope that helps you, it’s a significant investment to have solar and lithium, I would be sure you get value from it, for your camping style, before you sink that capital.

[LNBright]

Originally Posted by Tablerocked

I live in the Ozark mountains and plan to do a lot of camping nearby that has 30/50 amp hook ups.

That's it. If you're camping w/ hookups, solar is superfluous.

If you do occasionally camp where you don't have a hookup, and it's fully wooded, then a generator would suit you better. If you're occasionally boondocking in sunny locations, then maybe a suitcase solar setup would be best for you instead.

But if you really are always at a hookup, then you really only need solar as a backup, if the power's out at the site, etc.

[jan55255]

I'm not an expert and haven't priced anything out; however, I think to get the benefit for boondocking and not use a generator, you need to change whatever inverter you may have. You would need a 3000w inverter with 3-4 lithium batteries. It adds up, but if you like parks in the off season without a shoreline, it may be the way to go.



The question is, will changing the inverter cause issues with the electrical system?

[Peter417]

Originally Posted by Tablerocked

I’m an electrical engineer and I’m having a hard time justifying the enormous cost of solar vs the fairly low power return, especially in my area where our camping will be in heavily wooded areas.

Am I nuts to take that money and add more Amphours to my lithium battery bank?

Does anyone have any real data showing use by type vs lithium capacity vs time?

I live in the Ozark mountains and plan to do a lot of camping nearby that has 30/50 amp hook ups.

We also camp in the Ozarks. Solar would be worthless most of the time. I would add a 2200w generator before I would add solar. Almost all the state parks have power, Water and sewer are much harder to come by.

[oldenavy]

Another EE here. If you're always camping with shore power hookups, neither solar nor Li batteries make any fiscal sense.

We do some boondocking and plan to do more, so we upgraded to 300Ah of Li batteries and 400w of solar over the winter. Looking forward to trying it out this year.

[pteck]

Originally Posted by Tablerocked

I’m an electrical engineer and I’m having a hard time justifying the enormous cost of solar vs the fairly low power return, especially in my area where our camping will be in heavily wooded areas.

Am I nuts to take that money and add more Amphours to my lithium battery bank?

Does anyone have any real data showing use by type vs lithium capacity vs time?

I live in the Ozark mountains and plan to do a lot of camping nearby that has 30/50 amp hook ups.

I'm sure you understand that solar and batts serve different purposes. One is a potentially unlimited source of power generation. The other is strictly reserve.

Without shading, each 100W panel is generally worth ~30Ah of daily generation. Most rooftop arrays are in the 200W-400W, worth about 60-120Ah daily. That's substantial and can *potentially* provide power indefinitely.

Yes, in heavily wooded areas, it would complicate generation for solar. How heavy is the canopy? Would solar even generate a portion? Say 5Ah daily/100W panel? I've not been in the Ozarks, but is portable solar an option to capture direct sunlight?

Generator and your car are reasonable backups to put charge back into your batteries.

Just be aware with lithium, there's some substantial changes necessary. Including converter, battery capacity monitor, mods. And you won't want to be anywhere near limits as when a lithium battery is spent to capacity, it's a hard shutdown. Vice traditional lead acids where they have built in reserves at the cost of battery life.

[Peter417]

We knew we would be moving our battery around a bit so we went with a a battle born battery. It requires no special charge controllers. Most RVs will only charge the battery to about 70% capacity. The side effect of this is a longer battery lifespan. My current charger is similar but it is capable of topping off a lithium battery but it requires my to push a button when I want to do so.


Portable panels would work in some campgrounds but it would not be reliable. We can also go a week or more without the sun. We get nearly 50 inches of rain a year in the Ozarks.

If I depended on power while camping in the Ozarks, I would pick a generator paired with sufficient lithium batteries for the tasks. I would add solar after that for a more robust setup.

[Bhmack]

I added 200ah of BB batteries and all the fixings to my 16rb Caravel and a 2200i generator. I’ll wait on additional solar as my TN campgrounds and off grid camping on the lakes are usually shaded and isolated. I’ll convert the gennie to Propane and roll with that for now.

[Bill M.]

If the OP is an electrical engineer and he already has lithium the question might be sorta rhetorical. I would like to see his power use schedule laid out.

[Jim J]

I wanted to get Solar for my AS for occasional boondocking trips. My usage history told me I could go about 1 and a half days on my Original pair of flooded lead acid 12 V batteries. I wanted to be able to recharge in one day, what I used in one day if it was sunny out. For me that was 200 watts of solar panels.

I looked at 3 different options:

1. Professionally installed 200 W rooftop solar. $4855
Victron charger and monitor, New AGM 220 AHr batts

2. Same system But DIY $2500

3. Renogy 200 W Suitcase Solar, 30 ft. extension cables, Q works monitor, Keeping original Interstate batteries. $568



I chose option 3 and it has been working well so far . Biggest drawback is getting it in and out of the trailer and hooking it up when I want to use it. I built a shelf in the rear trunk of my FC 30 for it to sit on when traveling.

[CarterKraft]

In full shade all bets are off.

In full sun it pays for it self very easily without Lithium batteries, with lithium batteries you have to sharpen your pencil.

I have a 400w 4 panel array, Victron charge controller, chi-com 2000w inverter and 2 6v lead acid batteries. That's a $1000 system DIY and in full sun it creates perpetual power with no AC use.

If you need AC, Shade etc. then you will have to reconfigure your system to handle those issues.

[pteck]

Originally Posted by CarterKraft

I have a 400w 4 panel array, Victron charge controller, chi-com 2000w inverter and 2 6v lead acid batteries. That's a $1000 system DIY and in full sun it creates perpetual power with no AC use.

Exactly. Almost independent of batteries, with 400W worth of solar, it's potentially perpetual power. I almost never plug into the power pedestal because of it, and my converter is perpetually off even if I do.

Solar is dirt cheap these days and I was able to also set mine up like yours also under $1k.

To answer the original OPs question about adding batts, for another $1k, I'd added a secondary 100ah lithium battery bank via a portable Goal Zero. This powers my toys and 120V uses (another reason I rarely need to plug into the pedestal)

1) 400W solar ($700)
2) 2x 6V golf cart batts, 215Ah 80% usable ($210)
3) Goal Zero Yet 1000 with charging cable, 98Ah ($875)
4) Transfer switch ($75)

$2k invested - 300ah total system reserve, 400W solar

https://www.airforums.com/forums/f37...um-196422.html

[ddruker]

I'm also a EE. And I LOVE my solar panels - I installed 600 Watts of flexible cells up there about 8 years ago. They very much changed the way I use the trailer.

Basically, post solar panels I never have to worry about keeping the house batteries charged. And I also almost never bring a generator on the road with me now - the panels keep the trailer fully charged when camping. So my only limitation for boondocking is water usage.

So for me, it's very much a convenience thing - I just don't have to worry about my 12V systems any more. They pretty much take care of themselves. On 90% of my trips, I just don't worry about charging them, dragging around a generator, dragging around fuel etc. And if you do the install yourself, it's very affordable, plus you can deduct a big chunk of the cost on your income taxes.

If I'm going somewhere where I know I will be in full shade - like Yosemite Valley - then I can charge my house batteries from the inverter in my F150 - but this is very much an exception for me.

Folks above detailed the costs - my materials were well under $1,000 all in. I would do it again in a heartbeat!

[richard5933]

All depends on how much you boon dock and how much you hate hearing a generator run.

We have three folding portable 180w panels connected by a long cable so we can be in the shade and the panels out in the sun. Not always workable on a wooded site, but it helps. I can't stand hearing a generator so for us it's worth the expense. Others are fine just pulling the starting cord and letting it run.

[OutdoorIdaho]

The value of solar for me is that it is completely passive. I go hiking, fishing, and exploring all day and come back to batteries that have been charging all that time.
Of course, I still have a generator with me because, well, "Be Prepared".

[uncle_bob]

Hi

If you always have hookups, then anything past the cheapest "on sale at Costco" battery setup makes any sense at all. You simply can't justify it.

Even if it's a day or three "off grid", the Costco deep cycle cheap batteries are the winner. There simply is no way to beat the financially.

Driving down the road? Well, solar helps you there. Your charge wire from the TV is pretty anemic in this respect.

Parked in a parking lot here or there? They rarely are in the deep woods.

At least around here, hookups cost money. If that's $50 a day (as it may be), camping a hundred days a year (which is about what we do) gets you up to around $5,000. Cut that in half and .... geee ... that's a pile of cash. Do it for three years (which we have) and it's an even bigger pile of cash.

In a lot of places generators are a no-no. I have yet to run into a place that outlaws solar. No it's not going to hit 100% in the deep woods. In a reasonable selection of campsites out and about, you will see at least 50%.

Bob

[AldeanFan]

I have a 40w solar panel mounted on the roof of my Safari.
I won it as a door prize so it was free.

When the trailer is not in use the panel keeps my battery fully charged, and I leave the radio playing to discourage mice.

When I go to the races we normally have full sun, and only use battery power for led lights and water pump.
Anything beyond that we use the generator, but at the track all your neighbours have generators running so the noise is already a problem.

Family trips are almost always to a site with at least electricity if not full hookups.

Obviously if I were boondocking In the forest and had to blow dry my hair and microwave a burrito every day I would need a different set up.
Everyone’s needs are different.