Answer
By typing "square meters to square feet" into a search engine, or by using the conversion factor 2.54 cm = 1 inch, and remembering there are 12 inches to a foot, we find that 1 square meter = 10.8 square feet.
Assuming that one square meter at Earth's surface receives 1.0 kW = 1000 W of solar power, one square foot receives (1000 W)/(10.8) = 93 W, which is approximately equal to the output of a 100-W bulb.
