Note that I meant to write "This fellow did it with a 12V system", not a 120V system. Post is too old and I can't edit it now.
Originally Posted by elhora
What is the capacity of those panels? I do the numbers and if you have 1200w panels, you will not produce more than 800wats hrs for about 5 to 6 hrs depending position of the panels and time of the year, so best scenario 4,8 kwh or 3 hrs fully draining the batteries, I think that will not be enough to run the a/c, also you will need to put a soft starter in the a/c to be safe because after an hr or hr and a half running the system will not support the start consumption,
Please keep us posted in the progress of your system
At the time I posted I had speced different panels and a different layout; this is the current design:
Since then I have found these 440W panels that should fit:
440W 72Split-Cell Silver Mono Solar Panel by Solarever
I also found a solar tracker that looks affordable ($89 per panel):
Single Axis Complete Electronic Sunlight Track Solar Tracker Tracking System Kit
That specs out to 1760W (rated). With the solar tracker I hope to keep the 30% that's normally lost when panels lie flat.
Got the shelf for the compressor and spare tire fabricated in Salt Lake City:
(Also took the opportunity to add another axle to my overweight trailer, but that's another story.)
And I took delivery of the mini split. The company sold my (paid for) 9kW unit out from under me so I've got a 12kW unit now because they don't have any more of the 9kW units. Not happy about that because the minimal consumption may be higher. But, who knows, maybe it will work out better. This is all an experiment.
Next steps are:
• get a cage for the compressor fabricated
• install the 220V mini-split, the 48V battery, the new 48V/220V inverter and the 48V to 12V converter
• remove the old rooftop a/c, clearing the way for the solar panels
• install the solar panels
By my calculations, I should be able to run the ac during the heat of the day and still fill the battery—but not from a completely discharged state while run the ac unit. I just don't have enough roof area for more solar to do that. Still, running the generator a couple hours when boondocking to top off the battery thereby allowing me to get ac overnight is acceptable to me because the fully-charged battery should
be enough for the overnight cycle (besides, I have no choice). I might even get away with not running the generator for 85% of my boondocking days since not every day will be a scorcher.
I wasn't thinking I would need a soft start but I could be wrong. If the panels aren't generating full power, I would need to dip into the battery to start the unit. That means a hybrid inverter that can pull current from the panels and the battery. Hmm.
I'm not planning on getting rid of the propane. For the really hot weeks, I'm not anticipating having enough power to run my fridge and ac unit on solar so I'll continue to use propane for those weeks. However, I'm planning on using any extra power from the solar panels to heat water.
In theory, I should be able to boondock for two weeks straight without starting the generator—most weeks of the year. My grey water tank fills up by then, anyway. Head back to town to empty the tanks, get more water, fill the propane tanks and get more food.
If it weren't for the Internet, I'm setting myself up to be quite the hermit. ;-)
P.S. Finally found a way to post pictures. Upload the image to Google Drive, share it and copy the link address, post the link into gdurl.com
; use the link that service provides.