minimum amount of solar

I have 4 choices of comfort that makes a tremendous difference.

Thickly insulated Russian style komrad cap

Flannel and Cotton cap

Cotton stretch cover

Bald head (what's left is cut short.)

An exposed head really complicates comfort in cold weather.

Right, heated mattress. What was I thinking? The cold comes from below. My mattress is on lift-platform of the front through-storage where temperature is lower than in the trailer.

A fixed solar for me.

Hi Almot,

I'm firmly in the fixed flat panel crowd for solar installs on RV's.

I've graduated to an electric mattress pad now and find it quite wonderful. It has a 'pre heat' button, so no more climbing into a cold bed.

It does time out after ten hours and does require a pure sine wave inverter, but I have a lovely Victron 350 watt that works well.

I got mine at Aldi's (one of their specials of the week) for $59 USD.

100W solar suitcases like Renogy is an easy way to get a little solar but the cost is not so little. 200W permanent install on the roof will cost less than Renogy. Imitation suitcases I won't comment on. Renogy have an "acceptable" quality controller, not a top notch but Ok.

There are some benefits to portable method, like possibility (read - necessity) to tilt it to the sun, thus increasing the output. Though, 200W flat array without tilting would harvest more than 100W with tilting. Larger 500W array would generate a notable current even in a light rain or partial shade.

Another benefit of portable is that you can attach a long wire and place it out the sun if you happen to park in the shade. OTH, flat solar on the roof would often remain in the sun while the ground is shaded with trees and other obstacles. Depends on the area.

I tried the "comforter way" and found it working in a narrow range of temperatures only. Thin duvet needs another layer/blanket when temps drop just before dawn, and a thick duvet is heavy and doesn't conform to your body well. Besides, the usual problem of wintering in the South - it gets dark at 6pm and immediately it gets colder. It takes a lot of warm clothes to feel comfortable when you're not working or exercising. Propane heater (not a furnace) works better for me.

Some day I will try an electric blanket, I recall Pianotuna was satisfied with them (to certain point of course, given his unbelievably cold area).

To answer K and I's question (which is relevant to the OP's question, so we are not hijacking), this is a no-name Chinese imitation of a Renogy suitcase. I have it on an extra long, extra heavy cord, to avoid voltage drop. We park the trailer in the shade and try to put the panel in the sun.

When we are in a campground, we lock the panel with an extra long bike cable -- 30 feet! Got it at Harbor Freight. It keeps honest folks honest. A crook with a good bolt cutter could probably steal it easily. Never had a problem, so far.

And this 120 watt setup works for us even in the winter, as long as there is some sunshine. But again, be aware that we are very, very careful about power usage.

So in cold weather, for example, we just dress very warmly instead of running the furnace. We look funny. But if it works for Eskimos, why not for us??

Plus we use a down comforter at night -- the trailer often gets down to about freezing. We sleep like hibernating bears -- much better than at home.

Unlike bears, though, we do have to get up at night to use the bathroom in freezing weather. That is part of the fun, right?? ;)

Solar is "all or nothing" affair. They could get away with 100W if this is summer, sky is clear and they are not parked in partial shade. Too many "ifs".

500 watts is not an overkill. It can get rainy, cloudy, they will watch TV for 6 hours because have nothing else to do. With retirement approaching, there is a good chance that they will want to travel South in winter - in low winter sun 500W will work like 300W.

500 watts minimum is a bit far fetched when not using the furnace and watching TV only 1-2 hours a day.

I do not watch TV, but use the furnace every night (in the mountains) and easily get by on 200 watts boon docking for weeks at a time.

pinesman wrote:
....snip...... We do not normally dry camp when it is too hot and the small inverter we have is just to watch tv maybe an hour a day. Thanks.

At least 500 watts "minumum". You may want to watch tv for two hours some day. The sun may not shine all summer.

pinesman wrote:
All of our lights have been replaced with LEDs, we take short showers, and do not use the furnace. The two fantastic fans are the biggest power users we have. For those of you with a similar setup, can I get by with one 100 watt panel to just keep the batteries up or is that just a dream? We do not normally dry camp when it is too hot and the small inverter we have is just to watch tv maybe an hour a day.

100W might work in summer.

When you retire and want to extend the season, possibly going further South in winter, and stay a week or two, you will find that it is warm but not always sunny. In such conditions 400-450W flat array is the minimum that would let you stay indefinitely, in any kind of weather, without a generator. This is - with your minimal energy needs. 2*250W panels and MPPT controller is a no-brainer, easy #10 cable with standard MC4 fittings. Roughly $500 parts cost.

Also, consider catalytic Olympian heater. I installed mine permanently on the wall and run it before bedtime (when it's cold) with either screen door or window slightly open, so there are no issues with venting. Silent, hot (I got 5,000 BTU version, should've bought smaller 3,000 model), and very easy on propane. Fridge and showers eat more propane.

pianotuna wrote:

If I were the OP, I'd set a budget--and then buy the greatest number of watts of panels with a temperature compensated charge controller that has enough capacity to allow me to expand the solar harvest.

x2. There is no such thing as too much solar. One suggestion - instead of planning to expand, I would just install as much as I would fit safely. It is easier this way.

The 100 watt panel is the industry standard and good compromise of weight, size and cost. Start with a 100 watt panel, but buy a solar controller that can add capacity ie more panels. Your needs are minimal, but you want to be able to charge your batteries fully each day even in cloudy or rainy conditions. I would buy maybe a 30 amp controller. Use the right wire size, (big enough). Use fuses and a shunt for an inverter.