I'm stumped. Can someone answer this for me?

Energy is not a physical unit. It is a philosophical concept and an accounting technique used to analyze mechanical and chemical exchanges. In nuclear physics it is defined as a wavelength of light, in biology it is a synonym for metabolism, and in public utilities they say energy when they mean connectivity. Anybody who uses the word in any other context either does not know what he is talking about, or is peddling something you don't need.

The question should say "heat transfer". That is measured in watts per square centimeter per degree C. You would need an adjustable power source, a heater, a wattmeter, and two thermometers.