Re: Generator backup and PV, no batteries
No, the Xantrex XW hybrid inverter needs the batteries... And batteries are still the expensive/weak point/need replacing over time too which drives up the $$/kWH price of the power produced.
From my point of view, it is still a better solution (hybrid GT/Off Grid inverter) than a pure Off-Grid system. The ability to use grid for the 99% of the time the grid is up allows more energy to be used (over time; and more efficient/less battery losses) and less cycling stresses on the batteries--leading to a better $$/kWH price.
However, at this point, there is no "cheap" solution for emergency power other than the genset (which can become very expensive to supply fuel for if there is a prolonged outage).
Conservation so that you have the smallest possible loads and the smallest genset possible to run those loads can reduce fuel usage and storage needs by a whole lot.
20x BP 4175B panels (replacement) + Xantrex GT 3.3 inverter for 3kW Grid Tied system + Honda eu2000i Inverter/Generator for emergency backup.