Over the past few years, the use of fossil fuels as an energy source has been trending downward.  Many factors have contributed to this trend.  For example, it has long been recognized that the use of fossil fuel-based energy options, such as oil, coal, and natural gas, produces gases and pollution may not be easily removed from the atmosphere.  Additionally, as more fossil fuel-based energy is consumed, the more pollution is discharged into the atmosphere causing harmful effects on life close by.  Despite these effects, fossil-fuel based energy options still are being depleted at a rapid pace, and as a result, the costs of some of these fossil fuel resources, such as oil, have risen.  Further, as many of the fossil fuel reserves are located in politically unstable areas, the supply and costs of fossil fuels have been unpredictable. 
Due in part to the many challenges presented by these traditional energy sources, the demand for alternative, clean energy sources has increased dramatically.  To further encourage solar energy and other clean energy usage, some governments have provided incentives, in the form of monetary rebates or tax relief, consumers willing to switch from traditional energy sources to clean energy sources.  In other instances, consumers have found that the long-term savings benefits of changing to clean energy sources have outweighed the relatively high upfront cost of implementing clean energy sources. 
One form of clean energy, solar energy, has risen in popularity over the past few years.  Advancements in semiconductor technology have allowed the designs of solar modules and solar panels to be more efficient and capable of greater output.  Further, the materials for manufacturing solar modules and solar panels have become relatively inexpensive, which has contributed to the decrease in costs of solar energy.  As solar energy has increasingly become an affordable clean energy option for individual consumers, solar module and panel manufacturers have made available products with aesthetic and utilitarian appeal for implementation on residential structures.  As a result of these benefits, solar energy has gained widespread global popularity.