As a rule of thumb, pick a system that generates 70% to 100% of your annual electrical usage. Whether you lease or buy a home solar power system, you should know that you generally don't use the ...

In clean backup mode, your battery system is charged using only energy created by your solar panels. Once it is filled, any excess solar energy is used by your home or sent back to the power grid.

then you likely won't see as much of an efficiency loss with an AC-coupled system. DC solar that goes straight to power your home only needs to be converted to AC once before it reaches your house.