Photovoltaic (PV) systems have been around for a while now, but the growth of rooftop PV installations has increased dramatically over the past few years. What is causing this surge?
There are many reasons PV systems make sense now and for the future. Energy costs will continue to escalate, and supply will continue to be chased by demand. Expanding the use of renewable energy sources such as PV can help meet some of the demand and relieve some of the cost pressures on electricity.
Rooftops are a good place to locate PV systems because they are typically little used and are free from obstructions that can hamper PV performance. Utilizing rooftops can also reduce land use, making it available for other purposes, or simply as green space.
PV is a clean, unobtrusive energy source, meaning that it does not pollute while it produces energy; eliminating the environmental issues associated with many other forms of electricity generation. The question arises as to whether the net benefits from PV electrical generation outweigh the monetary and environmental costs associated with production, installation, and disposal of a PV system. That analysis has not been done, but it could prove interesting.
Incentives from federal, state, and local governments and from utility companies can ease the financial burden of an investment in PV, plus encourage its introduction and the development of more cost competitive PV technologies. A good source of information on incentives is the Database of State Incentives for Renewables and Efficiency at www.dsireusa.org.
Increased use of PV can help reduce some dependence on foreign sources of fuel, leading to less potential for hardship due to supply disruptions.
While improving energy efficiency in buildings is essential (by way of reflective coatings, better insulation, high efficiency windows, day lighting, etc.), it cannot be the only component in pursuing Zero Net Energy Building design. Sources of renewable energy are necessary to supplement conventional sources.
Finally, as the cost of conventional energy sources goes up and availability goes down, the cost of solar electrical production is approaching parity with most conventional sources.
PV systems can be expected to last 20 years or more, so they should be paired with a roof system that doesn’t require much routine maintenance and has a similar lifetime.