Light Energy into Heat

Light causes the surface to heat up, and doesn't the lense at least add a little? If you have awide area when you are magnifying, it doesn't heat up as quickly so the short term heat gain is higher.

If it were so you could build a machine that uses one lightbulb, makes the light go through thousands of lenzes, till the total energy added is more than the energy needed to power the lamp and you'll have free energy.

Would be funny though to power your house with only one lightbulb