Under-Floor Nanowires Make Energy
A long-term solution to save energy for the Beaverton City Library would be using under-floor nanowires to make energy, thus having to buy less electricity. Nanowires are very small wires that cannot be seen with the naked eye. In more scientific terms, a nanowire is a wire of diameter on the order of a nanometer (10−9 Meters). Nanowires can also be defined as structures that have a lateral size constrained to tens of nanometers or less and an unconstrained longitudinal size. The under-floor energy generation can only be done by a special type of nanowire called the piezoelectric zinc oxide nanowire. When this type of nanowire is pushed down on, causing it to bend, it generates energy. Millions of these nanowires could be arranged in an array under the carpet of a floor, so when people walked on it, they would make the nanowires bend and generate energy. They can generate 2-4 watts per square centimeter.
When bent, the coupling of piezoelectric and semiconducting properties in zinc oxide creates a strain field and charge separation across the nanowire. This charge separation generates/is the energy. The nanowires generate energy as long as they are bent and have an efficiency of 17-30%. There is about 328,956 square centimeters of stair area at the library. This means if three people walked up both sets of stairs (that means six people in all), by the time they got to the top, they would have generated between 658 - 1,315 Kilowatts! That’s a lot of power!