Historically, space programs were the largest supporters of PV technology, since the system was the best energy source for their satellites. The industry has since grown and you have probably seen PV systems used to power electronics, cars, houses, commercial buildings, and to supplement power grids. Due to increased efficiency, decreasing cost and increased environmental concern, photovoltaic installations have increased dramatically in recent years.
A photovoltaic system uses solar panels to capture sunlight’s photons. These solar panels each have many solar cells made up of layers of different materials. An anti-reflective coating on top helps the cell capture as much light as possible. Beneath that is a semiconductor (usually silicone) sandwiched between a negative conductor on top and a positive conductor on bottom. Once the photons are captured by the solar cell, they begin releasing the outer electrons of atoms within the semiconductor. The negative and positive conductors create a pathway for the electrons and an electric current is created. This electric current is sent to wires that capture the DC electricity. These wires lead to a solar inverter, which then transforms it into the AC electricity used in homes. The more solar cells you install, the more electricity is produced.
Solar panels are made up of many solar cells. The number and type of solar cells used depend on the resulting voltage required of the solar panel. For example, a common 12 volt solar panel will contain 36 cells. These panels are then installed in ways that capture the most sunlight.
Solar panel installation begins with you choosing the type of panel. Traditional solar panels are the most efficient; however, they are larger and heavier than the other two types. Thin-film PV panels are lighter and cheaper than any other solar panel, but are generally less efficient. These are usually residential solar panels. Concentrating PV arrays are new and use lenses and mirrors to concentrate sunlight onto the solar cells. These arrays are the most efficient but can only be used in very sunny areas, such as the American Southwest.
Once you select the solar panel type, the next step is to choose the best location. Installers will analyze the path of the sun over a particular property and take note of any shade to choose the most efficient location for the panels. It is best when solar panels are oriented toward the south and are not shaded at all. By doing so, the panels capture the most sunlight throughout the day.
You may ask whether PV systems or solar thermal plants are the better option for harnessing solar energy, and that debate has raged for many years. Solar thermal plants use the sun’s energy to heat a liquid (often water) or gas to high temperatures. The resulting heat energy is then used to power a generator and create electricity. PV systems, on the other hand, convert sunlight directly to electricity. Solar thermal systems are best used in large energy plants while PV systems are usually the best option for homes and businesses. Here are some pros and cons of each method.
Solar thermal plants are better at distributing energy during off-peak hours or seasons through long-term storage of electricity.
Solar thermal energy is more efficient at harnessing energy from sunlight.
Solar thermal systems use less roof space.
Solar thermal plants are more expensive to run and the excessive heat may cause safety concerns.
Solar thermal energy is most efficiently used for heating things, like water heaters, and is less efficient as a form of electricity.
Solar thermal systems require the use of a generator to produce electricity.
PV systems produce the most energy during the summer, when it is most needed to power air conditioning.
There are no moving parts and little to no maintenance needed.
PV technology has been in use much longer, proving its usefulness.
PV energy is much more versatile, since it converts sunlight directly into electricity without generators.
It takes longer for the energy savings to pay back the cost of installation.
PV systems have a lower capacity for harnessing sunlight.
PV systems collect energy only during sunlight hours.
There are many advantages of solar energy, and photovoltaic systems are a powerful form of clean energy. A properly installed PV system will provide you with plenty of power, lower your electric bills, help during power outages and may even earn utility bill credits if excess energy is sent to your local power grid. Through this amazing technology, you can be confident in producing environmentally friendly and sustainable energy for your family.