Something to consider is the management. We lived off grid for 10 years beginning in the late 70’s. The system was a 3KW Dunlite wind generator and a bank of 19 FLA batteries. Inverters were terribly inefficent and VERY expensive so we went 114Volts DC. Payoff was 6 years and eveyrthing worked well. August was always calm so we had a generator to recharge the batteries. Technology is much better today but a factor to consider is the management of any system that relies on the weather. Computers make it all easier but it still needs to be done. Clearing snow, adjusting the load, checking the SOC of the batteries and other tasks are part of the territory. If your electric bill is several hundred dollars a month then this may be insignificant. Ours is $55-$75. At our use there needs to be other motivation besides money. Having a grid tie system transfers the care of most things to the power company. We know how reliable solar power can be having relied on it in our traveling van for 5 years. Having a self contained system means you have power when the power company is off and in cold country we have to keep a generator anyway. Now in our 70’s, we use a mix of propane and electricity that is very modest but it is still easy to design a system that if self installed has a payoff of 6 years. With time afforded by retirement the management for us would be fine.