Overthinking/expecting too much from solar?

[dphaynes]

Originally Posted by cwsqbm

Running the washer/dryer off batteries isn't practical. I've read articles on off-grid houses, where the number of solar panels and weight of the battery bank aren't limited, and they still fire up a generator to do laundry (although they generally use a clothes line instead of a dryer). Generators need regular exercise.

That's interesting!

Now that you mentioned 'firing up the generator' for it I'm thinking that I read it's necessary to fire up the generator once a month for maintenance reasons. I could use that as an excuse to do laundry etc. I've read recommendations to run it as 2 hours so could get a few loads of laundry washed. I'm planning on line drying when possible. So if I run it every other week I should be covered laundry-wise.

The AC is the only other issue, and I think I'm going to look into the external windshield cover like JFNM suggested. I guess I also need to invest in a couple of good, small oscillating fans.

Thanks for the info!

[dphaynes]

Originally Posted by Lv2Roam2

I've got 1400 watts of solar which will sustain us (almost) indefinitely with good sun conditions in lower latitudes with a residential frig and moderate use of TV, LED lights, water pump and small electrical items - plus unknown phantom draw. A/C and extended M/W use requires generator runs.

Recommend you consider the following if you're pressing ahead:
- Previous responders have provided solid advice
- Talk with AM Solar staff (search postings on IRV2 and web)
- Think about lithium battery bank versus AGMs (more useable capacity - expensive, but do the math on useable amp hours versus other battery types)

That's good to know, thanks!

I almost never watch TV but I do have the constant 220W draw (fortunately during daylight hours) for a big desktop computer and monitor plus a laptop, jetpack etc.

It does seem like adding to how much I can store (e.g. lithium batteries or extra lead acid cells) makes more sense than adding to how much I can generate.

Thanks!

[Nana25K]

So just out of curiosity how large are your holding tanks for gray water. The water from the washer needs someplace to go. Even being conservative we get about 2 weeks off grid and that certainly does not include running the washer.

[dphaynes]

Originally Posted by WYRon

I think you've gotten some good advice from the earlier postings, including checking with AM Solar. I have about 1,000 watts of solar on my coach, which keeps me pretty happy occasionally boondocking and keeping the refrigerator running in storage (no electricity). As said earlier, the solar is just to keep the batteries charged. What will determine what you can run, even for a short time, is the peak current requirements for your devices. When you talk about air conditioners and the like, I think you're going to be disappointed. Here's a link from Honda Generators showing the approximate start-up wattage and running wattage for various appliances. Honda Generators wattage estimates. They list RV Air Conditioners, and for a 13,500 BTU/hr unit the start-up wattage is 2,800 watts, compared to 1,800 watts continuous. I have a 2,800 watt inverter, but I don't think it would handle even one of my 15,000 AC units starting by itself. I certainly wouldn't have enough solar to keep the batteries charged for even an hour or so of operation a day.

For myself, I'm lucky to get 500-600 watts peak out of my solar, and you can't count on more than 8-12 hours per day (not all at peak power). When you add it up, I can run the refrigerator all day, and occasionally the lights, computer equipment, and televisions. Microwave and coffee maker added in will ensure I need to run the generator a bit. I wouldn't even dream of the AC and washing machine, let alone dryer.

Thanks that's a great link to the Honda estimates. I'm not sure what the hell kind of stereo they were looking at that takes 50W to 200W to run! The 220W load for my PC includes 280W 5.1 speakers and 2 24" monitors! (with everything plugged into a Killawatt)

The one load I do run frequently is an electric kettle to make tea. Guess I better plug that into the Killawatt.

Thanks for the info!

[Busskipper]

Originally Posted by dphaynes

I'm looking at a 2017 Tiffin Phaeton w/all electric and 6 battery options.

Talking to the Tiffin folks, it sounds like the inverter doesn't run the washer, dryer or AC units.

- The washer is ~1,300W, draws max 11A
- The dryer is ~1,300W, draws max 10.5A
- Each AC unit is ~2,200W draws max 16A

I'm going to be living in it full-time and working from it as well (computers to the tune of ~220W load during daylight hours)

I want to put solar panels on it (900 to 1200W) so that I can avoid burning diesel as much as possible.

It seems like if I upgraded the inverter to 2,800W or better, it should be able to run any one of the washer, dryer or AC at a time and still have sufficient capacity for normal lighting and small electrical loads.

Am I being stupid/impractical? Well I know I'm stupid/impractical, but this time I mean specifically with respect to a PV array on an RV

Any thoughts/recommendations/pointers would be appreciated. I did a thread search and didn't find anything that looked related.

Am I being stupid/impractical? just will not work, sure this has been said to you before.

First thing is to find Electric - if not then a small Inverter Generator - 2200 surge - 1500 watt running - they will run all day on a couple of gallons of fuel and then if not electric run the Onan to power the big users.

Second thing is to locate in an area that is temperate - you have wheels so just keep yourself at the proper locations - North South - Higher elevation lower, So as to not need so much energy to just live.

BOL,

[ecurb74]

Something about like that?


Bruce & Teresa
2000 Foretravel U320 4010
Cummins ISM 450hp
Allison HD4060R 6 Spd W/Retarder

[montyhp]

I don't know how this solution would work in a big coach:

https://youtu.be/p9cU_R-KMCA

This guy (RVerTV) is running a swamp cooler off a small solar set up. If you are in a dry climate it should work quite well (will dump a lot of water vapor in the coach, though).

I would try this if I were in your shoes.

[Crasher]

As a simple and low cost option, do what I did. I only have 640 watts of solar, but never intended to be completely independent of the generator. We found that the noise of the 10 KW gen was too noisy to use in the evening. I bought a 2 KW Honda that runs a 40 amp smart charger. I set it 50-75 feet away from the coach and can barely hear it. On just the load of the charger, it will run for 10 hours on a gallon of gas. The solar keeps up during the day and on cloudy days, I start the Honda at 5 pm and let it run till bed time. Several of our friends without solar just run a Honda to keep charged up. The 10 kw gets used only for the cooktop or AC if needed. We never wash clothes till back on shore power. FWIW, it is legal to dump grey water on BLM land in all but two places in AZ.

[az99]

How many hrs. could you run the generator for the fair price the dealer is installing the solar for? When you have the AC running you will not hear the generator running if that is a concern. Even a 10 KW generator uses very little fuel if not under heavy load. The generator is also charging your batteries when running.

With solar you have to always park in full sun. That means the AC will be needed alot. Without solar you can park in a shaded area.

I have 10KW of solar on my home. I would never try to rely on solar for any off the grid reliable power.

Save your money on the big solar install and just get the regular system designed to keep the batteries charged when not in use.

[pasdad1]

How about this ? 😃

[dphaynes]

Originally Posted by ecurb74

Attachment 128496

Something about like that?


Bruce & Teresa
2000 Foretravel U320 4010
Cummins ISM 450hp
Allison HD4060R 6 Spd W/Retarder

Oooh oooh! That'd go perfectly with my colander cum alien microchip protector!

[dphaynes]

Originally Posted by pasdad1

How about this ? 😃

Attachment 128506

Where's the optional pop-up windmills? Looks like room for a couple of spring-loaded 20' aluminum poles, one hinged at the front and one at the back.

[TQ60]

Hake sure if you are ordering new that the battery plant and inverter system will do what yiu need if only for very limited time.

HVAC units have a high inrush starting current that most inverters will not tolerate.

A few manufacturers offer one ac unit operation on battery so it is off the shelf so to speak.

Next consider the engine alternator and charging system as you want the biggest one available just because.

Now stepping outside the box...

You could build a trailer that could be your power plant...

Either stacked with batteries and deployable panels so you can make a solar array or a silent generator to charge them.

Just crazy ideas...

Noise should not be generator issue as they do have "theater models" that can be real quiet.

[dphaynes]

Originally Posted by montyhp

I don't know how this solution would work in a big coach:

https://youtu.be/p9cU_R-KMCA

This guy (RVerTV) is running a swamp cooler off a small solar set up. If you are in a dry climate it should work quite well (will dump a lot of water vapor in the coach, though).

I would try this if I were in your shoes.

I actually thought about swamp cooler, with 3 AC units it seems like one could be replaced with a roof mounted swamp cooler. I found a TurboKool model, draws ~5A

My concern would be with making it too humid inside the coach. I know swamp coolers work well in the desert, I've lived in Phoenix and Las Cruces and used them for cooling, but pumping humid air into a small space just gives me pause. I just have no clue if it'd make things too wet in an 8x40 space.

BTW that particular cooler the guy picked got 30% one-star reviews. Even really bad products generally only get 15-20% one-stars. That may be a new record for products I've viewed on there!

It looks like there are some decent USB powered small DC fans out there. If I charge some small USB battery banks while I've got solar during the day I could use those at night rather than taking power losses using the inverter to run AC ones.