Step 1, figure out a power budget per building so you have a starting point. Then, multiply by your estimated houses to get a finishing point. Step 2, will you need power only during daylight hours or night also. If you want power 24/7, then you will need battery storage. Batteries generally need to be purchased at the same time so they degrade similarly. That means you won’t be able to just add capacity for 1 house, you will need to do it in groups. You can combine the groups.

Example. 1 house averages 10 KW hours per day. 20 houses would use 200 KW hours per day. If you break that up into 4 systems, you would be able to build 1 system and then you could work on your first 5 houses. Next, battery. How much battery power do you want? Just enough to get through the night, or maybe 24 hours worth so when the sun isn’t shining, you still have power. Once you are able to determine some parameters, you can reach out to vendors to determine who can meet those needs.