What are photovoltaic cells?
Photovoltaic cells, also known as photovoltaic panels, are one of the most common ways to harness the sun's energy. Photovoltaic (PV) cells convert solar energy into electricity.
Once these cells are all wired together, they are able to harness enough solar energy to not only power a home but also return energy to the utility company. This is called "net metering" and can further reduce your electric bill when you have to purchase electricity from your power company.
PV cells can be used in a variety of applications. The most common application is in a solar collector panel. These panels incorporation several cells in one unit.
These panels present several challenges. Aesthetically, they are not the most pleasing. Many neighborhoods have covenants and restrictions that prohibit the installation of these large collectors. They also require periodic maintenance and cleaning. This is not that big of a deal, but it does require getting on your roof and the potential risk of falling.
PV shingles provide a good alternative to the panels. These shingles incorporate thin cell technology, which allows for a flexible solar collecting roof shingle.
PV shingles look like standard asphalt roofing shingles. They are installed with similar materials, but require some extra work. Each shingle has a set of wires coming out of the back of the shingle. These wires are guided through your roof and into plastic or metal runners that are attached to your roof trusses. These wires are then routed to an inverter, which changes direct current (DC) to alternating current (AC). AC is what most household appliances use. During times of less demand, this power can be stored in battery packs and then accessed when demand increases.
The advantages of the PV roof shingles are numerous. First, you can install them in almost all communities without violating neighborhood covenants/restrictions. They are also a good way to harness solar power without the bigger expense and maintenance associated with solar collectors.
There are a few downsides to PV shingles, however. Although they are cheaper than solar collectors, they are still an added expense to a new home. You need to do your homework to figure out when they would pay for themselves. This is based on your local energy costs and the amount of sunny weather you receive. The other downside is that they are half as efficient as standard PV panels. Therefore, you need twice the amount of roof space to produce comparable electricity.
PV systems provide homeowners and businesses with an efficient way of creating electricity from the sun. As technology improves, the cost of these systems will come down and their efficiency will go up.