I have a 950 sq ft cabin 100% off the grid. Currently power the cabin with Honda 7000i generator. I have a main panel in the cabin with a total of 6 breakers (well pump 1/2hp 10gpm - dual 20amp breaker, loft lights - 15 amp breaker, kitchen lights /outlets - 20amp breaker, hot water heater (12 gallon 110v) - 15amp breaker).
A 1/2hp pump is not too bad, just half the size of mine, which runs on 100% solar now. Very doable with a number of inverters, though I would NOT recommend a transformerless model. Outback, Magnum, and Schneider all make split-phase 120V/240V sine wave inverters that would be perfect for your pump.
There is one cable that comes out of my panel in the cabin with a NEMA L14-30p 30amp 125/250v 4 prong plug that connects to my generator and this powers the entire cabin effortlessly.... My biggest draw is the well pump which will surge up to about 1900v when it kicks on. I would love to use solar to power the entire cabin but can use the generator to run well pump if I had to.
We can use the wellpump as the model for the rest of the cabin. That is, design the system to run the wellpump, and it will run everything else.
Here is a table of pumps from another site. Looking at the table, you'll need to put out at least 6.0A at 240VAC. That works out to be about 1440W. My usual plan is to double the amount of panels for the load. So, if your load is about 1440W, have 2880W of panels. You can get 12 250W grid-tie panels for about 660$ in my area. Wire those into a 3S4P configuration. If you put them on rotating ground mounts like I did, you might get by with just 8 panels. Wire those in a 2S4P configuration.
We have other things in the cabin like microwave, Kureg & toaster that also have a pretty good but brief draw. I understand with a DIY (cost efficient) system I would need to be selective on what appliances I use together and when. I mainly plan to run lights, TV, power outlets and charge phones. Having said all the above..... I would like to be able to hook the solar system to my panel and when necessary switch over to my generator.
With a good inverter, like Schneider, you can couple your generator directly to the inverter.
Free Shipping! Schneider Electric Conext SW4024-120/240 Inverter/Charger, 4000W, 120/240VAC, 50/60Hz, 30A Transfer, 24VDC, 90A Charger, RNW8654024
ressupply.com
You can either use the generator to charge the batteries, or use it to power the well pump when the sun isn't shining. But, a system large enough to power the pump will easily power everything else, so things like standard refrigerators, TVs, and air conditioners are all doable.
. Can I switch between solar and generator and would I need to do anything inside the panel? I think I would like to go with a 24v system and I have been looking at the PIP LV2424 MSD (AIO) and the 24V LiFePO4 Powerwall battery bank. Does anyone have experience with this and would it provide enough power to supply my well pump and water heater? I've attached a couple pix to give you a visual of what I have now. Any input, thoughts or recommendations would be very much appreciated. Sorry for the dissertation!
For sure the well pump can run solely off of solar, but solar electric hot water is a real waste of resources. I think it is far more cost effective to have gas hot water, and I have an on-demand propane hot water heat at my own cabin. I'm going to recommend this battery. This is what I myself will be buying shortly to upgrade my own system.
www.rollsbattery.com