text: Best price about for LiON battery storage is $400/kWh.  Average U.S. home consumption is 1.2kW for 24 hr = 30 kWh/day.  So your 1-day storage system would cost you about $12,000.  But if you really want to go off the grid year-round, you will need about about 10 kW of solar generation ($30,000) and 10 days of storage ($120,000) to endure the shorter days and multiple sunless days of winter without a grid safety line.  Your cost of power over the 10-yr life of your batteries (if you are lucky) and 25-yr life of your solar panels will be about $1.00/kWh instead of the $.0.13/kWh from the power company.  Your power waveform will also be spikey and choppy because it is coming from inverters, and you will have less capacity to start large motors without browning out the rest of your appliances and loads.  Hope you don't have an electric car or electric tankless water heater or you will need a multiple of the above hardware.