I built two 5kwh storage systems using as few moving parts as possible, so they are more easily maintainable, using LiFePo4 cells. Theyve been our primary source of power for 4 years now. We charge them with solar, and augment with small charging generators in the winter. Next power generation project is a simple waterwheel, with a truck alternator. The key though, for us, has been to see what things we can remove from mainstream power dependency. i.e. laundry, refridgeration, etc. It's been working for us.