There is another, less conventional solution, and that is to lay down a heap of cats-eyes [aka raised reflective markers] to delineate the edge of the areas. Use the powered lights for the formal lighting [=meet the ICAO standard] and then supplement them with a heap of catseyes as edge markings. The roads chaps do it for drizzly nights, so why shouldn't we.
I once had to light up a remote taxiway/apron complex without the benefit of the $$ to stick in power. I picked up a load of blue catseyes left over from a Malaysian Airforce order, and used them. When the aircraft taxied in with its landing lights on, the whole thing lit up like a Christmas tree. Cost about $1 per catseye. Call it $400 to transfom the airport.