Since we have been doing a bit of dry camping and I wanted to cut down on generator time, I have started to put together a solar system. I got a couple of new stick-on 140 watt panels for about $1/watt and have been looking into charge controllers. It turns out that, since the panels were designed for a higher voltage system, a good charge controller will cost more than the panels, so by the time I'm done there will be $800. or so in it. I am now wondering whether it is really worth doing. Of course, if I only use one panel, the controller is significantly less but so will the charge capacity.
What is the general experience with this stuff.
It all depends what you mean by "worth doing".
Cost effective? Not a prayer - buy diesel fuel for the noisemaker.
Possible to replace the genset? Not a prayer with 280 watts unless your lifestyle is significantly different than ours.
From my standpoint (already have 200 watts on the roof), if I had a chance to add another 280 watts for $800 I'd definitely go for it. If we had 400 watts total it would significantly reduce our genset runtime. Not anywhere near "eliminate our genset runtime" but it would significantly reduce it. At 400 watts we'd be able to drop from 2-4 hours per day to probably an hour a day and then let the panels top the batteries off. IMHO the 200 watts that we presently have is just enough to be annoying - not enough to really be useful but enough to show me that twice as much would be useful.
So I didn't really answer the question did I? Sorry. ;D
I believe it is worth doing. I got several damaged panels for free, (shattered, glass but still working) and I watched ebay for quite a while and got a smoking good deal on a Blue Sky controller and remote panel. So I've only got $307 and some recycled wire into the system. I made my own mounting hardwarde. It's only putting out 3.5A at 27V. However, it now keeps the batteries topped off when I'm parked at home and helps reduce generator run time a little bit. I will keep watching for good deals on panels and add as time an money allow.
I have seen a good deal on those stick on panels here in MI. Let us know how they work out. I wonder about getting over rivets.
On a side note, I wonder how long til someone sells solar awning kits!
Glenn
Agree with Bob that your meaning of "worth doing" is the key to answering the question.
If you want to now if it is economically justified, I'd say highly doubtful. I've looked at payback periods for home solar, and they have long ROIs, even with residential tax credits.
If the goal is really to cut down on generator run time, my gut says increasing battery capacity and/or charging capabilities would be a more cost effective solution. When most people run their generator for air conditioning or cooking, there is still extra capacity for battery charging that goes unused.
Lin:
I have no personal experience with solar... yet. I am working on making the necessary "plumbing" installation between my electrical bay and roof, so it will be ready when needed.
This guy full-times in a solar-powered fifth-wheel, and has a lot of great very detailed information on this very subject.
http://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/ (http://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/)
Hope this helps!
I am selling my Onan 6k as a result of an appropriate (for me) solar install.
Today with light clouds and the panels facing east (far from optimal) I collected the following.
286 amp hours
3.7 kw hrs
Peak performance was 590watts (~60%)
For me this was enough to...
Run 2 loads of wash and dry them
Have lights on when needed
Run the ceiling fan all day
Run laptop, charge phones, water pump, radio...
Use the side grinder to cut off some screws poking out in a storage bay
I chose solar as i dry camp for extended periods (basically all year). We built the electric and solar with this in mind. We put 1020watts on the roof to cover our daily usage and make sure we start the night at 12.8v on the house batts.
You can do it cheaper than solar resellers tell you. Read everything handybob writes on the subject. He covers everything.
Nope.
--Geoff
Cost effective? No.
Enjoy quiet? Yes
In eleven years ~80 hours on the generator.
There are a couple of ways to justify quite a large amount of money spent on a DECENT solar system - and it is probably easier to do in Australia than in the US.
Here, generators are mostly forbidden in National park camping grounds. They are also very much frowned upon in boondocking sites because we don't have a long-standing culture of running large generators 24/7. Also the RV's tend to be a lot smaller and not fitted with all the icemakers and dishwashers and coffee machines that drag a lot of power.
So having a decent amount of solar is the key to being able to boondock/dry camp for extended periods without having to run the generator. This means a huge saving per year by not having to pay RV park fees so the payback period is pretty short. Save RV park fees for say 250 nights a year x average nightly park fees = a pretty nice solar system.
We spent 4 months in the western states of the US and spent two nights on hookups and rarely used the generator unless the weather was really poor over several days and the Airstream has only a couple of small panels. Here, in the OKA which doesn't even have a mains hookup or generator, we are into our 6th month of almost continuous bush camping relying only on solar and charging from the engine when driving. Same with the MC8 when it is on the road. It does have a cheap generator but in three years was run two or three times, and rarely saw the inside of an RV park.
Now that solar panels are dirt cheap and solar regulators (eg Rogue MPPT unit) have come down in price, it is very economical to cover your roof with panels, maybe add a bit more battery capacity and by moderating your lifestyle just a little, dramatically slash your generator run time AND every morning wake up to a new view that doesn't include an RV parked 10' either side.
Cost effective??? We run bigrigs and are worried about cost effective!!!!!!
Perhaps "lifestyle-effective" then
The reason I wanted to install it was first, I would like to be less of the noise maker in this Forest Service campgrounds, and second, using a 7.5kw generator just as a battery charger when all the other generator needs are done, seems nutty. However as you can see, my commitment is not unshakable here. Because of the panels I have (280+ watts at 46 volts), it seems that the right charge controller runs about $300+. Although not prohibitive, the project is getting to be more than I wanted to spend. I suppose that I could just hold off until a find the right controller at the right price. My assumption will be that I will like the system if I have it.
The other alternative would be to get a small, quiet generator to use to top off the batteries.
We had solar on both our past full time RVs, and find it to be absolutely worth it... for us. The amount of freedom it bought us to go places was amazing. We don't even look at it in terms of money savings/costs - but rather the versatility a system buys us.
Now, there's no getting around occasionally needing a generator for things like A/C or less than ideal conditions.
We'll be approaching a solar install on our bus in the coming months, and very much looking forward to it!
Aside from the panels & controllers however, you need to look at it as a complete package - battery to store it, and reducing your energy usage to best utilize the energy you collect. If you don't optimize those as well, then no - it's not worth it.
- Cherie