Solar window inserts
Solar inserts seem to have their promoters and their detractors. However. Whether or not 'real' energy is created... people seems to "feel" warmer. What happens at the window is truly important. Windows are one of the keys to sustaining and lowering our power and energy costs. Small inventions like the solar inserts are just one way to improve your energy savings. The following link has the instructions to make such an insert. Take the time to read the comments after the main body... they too have interesting concepts to explore. http://www.instructables.com/id/Solar-Window-Inserts/