The large storage batteries that use sodium ion. They should be able to get like 5,000 full cycles before they degrade and can be buried or stored outside. That and a solar array on a roof should let most anyone be completely off grid. Full solar house that should last for 15 years before the system needs replaced. The batteries will last longer and be cheaper than lithium. Solar panel prices are consistently getting cheaper.
I think in 5 years time there will be a lot of the electrical grid system (for most who will be still attached to the grid) just getting power almost completely from solar, and storing enough in these batteries for the nights and cloudy days.