The lowest quote is the easiest one to accept and the hardest to live with. On paper, two solar proposals can look almost identical — same capacity, similar layout, a price difference of eight or ten per cent. The gap shows up later: in the equipment that was quietly downgraded, the documentation a lender will not accept, the performance that never quite reaches what was promised. Here is where the real cost of a cheap EPC tends to surface, and what to look for before you sign.

