The system can start small to be added on to as time and assets become available. A good start point is a few solar panels with a couple of 12 volt batteries and a 12 or 24 volt inverter. 12 volt inverters are usually less expensive and more available at this time. That doesn’t mean that they are better, just a good start point. If you start with 4 each 12 volt solar panels and hook them in parallel to use as a 12 volt system and later decide to make it a 24 or even a 48 volt system. The change can be made easily without new solar panel expenses, by rewiring the system to match the required voltage. You will need to add at least 2 more 12 volt batteries to make it a 48 volt system. Deep cycle batteries or even golf cart or heavy equipment batteries are a good start point for batteries. Nichol/Iron batteries are top of the line, but very costly. To build a 12 volt system with 2 each 400 watt solar panels and a 12volt to 110 volt inverter system and 2 each 12 volt batteries. could be built for about $3,200 dollars and be wired into 2 to 4 inside outlets that are only on the off grid circuit. Using only off grid circuits will keep down switching and over load protection equipment cost. This will also reduce liability and equipment damage accidentally.
Probably the best system you could build and with the best return to cost would be a 48 volt system. The ability to enlarge or add on to the system as your needs increase is the easiest with the 48 volt system and also the cheapest to add on after the original installation. The equipment cost will be greater but the advantages and wiring cost will be less. There isn’t much in the used market with 48 volt stuff, so most will have to be new product. If interested in a design or products to build the system please contact on the contact page or call 573-743-6357. I design, build and install systems of all sizes and can provide product and support for your own install. Thank You Calvin Allen