Introduction

Gas lines and high energy bills in the late 60's and 70's forced the world to realize that fossil fuels were not going to last forever. People began to employ methods of energy conservation in their daily lives. This movement resulted in oil being stockpiled and the cessation of drilling for natural gas. However, people became complacent as new oil sheds were discovered. The world soon lost sight of the fact that fossil fuels are a finite commodity, taking their availability and low cost for granted.

Now, at the start of the 21^st century, there has been a tremendous increase in power prices. Recently, California has had roaming blackouts, monitored power usage, and in many cases, power is just too expensive to use. The realization that fossil fuels are limited helped to spur a movement whose purpose was to find a different, possibly cheaper, form of energy to power our everyday lives.

Once again we are cognizant of the limited availability of fossil fuels and the negative environmental effects of their usage. The time to find alternative energy sources is now. If we do not want acid rain, smog, and temperature inversions to be a part of our future, we must seriously consider the use of alternative energy sources. Because solar energy is abundant and has very few recurring costs, it has the potential to be one of the best existing energy sources.

The abundance of solar energy is one of its most appealing characteristics. The sun continuously radiates approximately 2.94 x 10²³ kW of power. Of this amount, about 80,000 x 10¹² kW, or 10,000 times the current global energy demand reaches the earth. This is a great amount of energy that, for the most part, remains untapped.  However, recent advances in the field of solar cell technology have made the collection of solar energy more accessible and less expensive. The U.S. Department of Energy states that the cost of PV (photovoltaic)-generated electricity has dropped 15 to 20 fold, and PV modules now cost around $6 per watt and produce electricity for as little as 25 to 50 cents per kilowatt-hour.

The PV awning that we are proposing will be used on south-facing windows and will convert the sun's energy to usable electricity throughout the year. In the summer, it will also serve as a shade above the window to block unwanted heat from entering the building, thus reducing cooling costs. However, in the winter when the sun is closer to the horizon, it will still allow sunlight to enter and heat the building.

Traditionally, awnings have been either cloth canopies that absorb light, or metal awnings that reflect light. However, because our awning is integrated into the power grid of a building, it can both shade a window and collect electricity to offset the building's energy demands. Its simple design, which uses existing PV modules that can easily be tilted to maximize collection of radiation, makes it a product that can be used on buildings anywhere around the world.