Photovoltaic (PV) Solar Panels
Photovoltaic, or PV for short, is a technology that converts light directly into electricity. PV is a developing field and utilizes several different technologies: monocrystalline (single crystal), polycrystalline (multiple crystal), cadmium telluride, gallium arsenide, or amorphous silicon deposited as a thin film. The major advantage of monocrystalline cells is their higher efficiency and therefore smaller space requirements. Thin film can be cheaper to manufacture but is significantly less efficient, requiring more area which results in more labor, mounting hardware, and bottom-line costs.
PV solar panels are usually either roof-mounted or ground-mounted. On a rooftop, rows of panels (called arrays) are mounted to face south or southwest at or near a 30 degree angle for maximum efficiency. The PV solar panels are fastened onto aluminum racks which are then secured to the roof framing, providing sufficient support for the array. This same array layout can also be mounted on the ground if the property has large, usable ground space.
Pole mounts are also a popular system, especially in more rural areas. The panels are generally mounted on the top of the pole but can also be mounted onto the side. Top-pole mounts require a steel pole about 12 feet in length set in concrete. These systems may include an auto-tracking feature which will automatically adjust the angle of the panels to follow the sun’s progress throughout the day.
SunPower photovoltaic panels have a manufacturer’s warranty of 25 years, but are built to last for 40 years. For a PV system with a 10-year payback period, that means the panels can provide 20-30 years of free electricity.
Economic benefits: Sunlight is free, abundant, and dependable. Unlike power from the utility company, solar energy is not subject to rate hikes. PV Systems also allow for energy storage that can be used when needed when installed with a battery backup. As far as the savings of installing a PV System, the payback on a loan or monthly lease will be less than your current electric bill. How much does solar cost?
Environmental Benefits: Solar energy is clean energy: no CO 2 emissions and no cleanup. Because solar energy is renewable, it can help slow down global warming and its negative effects.