Is it possible to perform Life Cycle Analysis (LCA) of an off-grid system using HOMER?

The point of HOMER's simulation is to determine the feasibility and calculate the life cycle cost of a micropower system, which may or may not be off-grid.  We call that life cycle cost the "net present cost", and HOMER ranks the possible system configurations according to their total net present cost.  So if you are asking whether HOMER calculates the life cycle cost of an off-grid system, then answer is yes.