Define work. If you are standing still, holding a book, are you doing work?

No if you are standing still holding a book it isn't work, work is when you are doing something productive or trying to accomplish something such as when you make your bed or clean your room.

pe = weightxheight = 2000x1000=2,000,000joules

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000