Can something as simple as shade from a tree or paint help save on home energy bills? This experiment will help answer that question. The "house" in this case will be a small cardboard box. A 100-watt bulb in a reflector lamp will play the role of the sun.
First, set up the box. Make sure it has a lid that shuts tightly. Put a thermometer inside to measure the temperature. Then, arrange the light so that it shines directly on the box. After 20 minutes, record the temperature inside the box.
Next, set a house plant between the lamp and the box so that its shadow rests on the "house." You can also use branches broken from trees or bushes for this, instead of a house plant -- just stand them in pots of sand to provide stable shade. Check the temperature again after 20 minutes. Did the shade keep the box cooler? Try different plants with different types of leaves. Which makes the most difference in temperature?
To test paint's energy effect, take two identical boxes and paint one white and one black or a dark color. Put each an equal distance from the light and record the temperature inside after 20 minutes. Which box gets hotter? How would this affect energy usage if it were an actual house?
Basically, choosing the right shade trees or exterior paint color could help save energy if they keep a house cooler in summer and cut the need for air conditioning. In winter, however, it might be better not to have shade, so that the house could absorb heat from the sun. In that case, trees that lose their leaves in winter might be the best energy savers [source: Energy Information Administration: Sun].