PV is an acronym that stands for photo-voltaic. The term photo-voltaic represents the union of two words: photo meaning light and voltaic meaning electricity. Photo-voltaic systems convert light energy, photons, into electricity through the photoelectric effect. The first photo-voltaic cell was made in 1883. The first practical solar cells, ones that created enough electricity to be worthwhile, were made in the late 1950s. The first real-world use of a solar panel was on the satellite Vanguard 1 in 1958.
A complete solar electric system is made up of several building blocks. At the smallest level there are solar cells. Cells are manufactured from semiconductor materials, such as crystalline silicon, sometimes “doped” with boron and phosphorous. Cells are electrically connected and packaged to form a solar module.
Solar modules are wired together in series and parallel to create the PV array, producing direct current (DC) electricity when exposed to sunlight. Because almost all buildings & houses utilize alternating current (AC) electricity, the PV generation must travel through an inverter, which changes the DC electricity from the array into AC electricity for the building’s consumption.
PV systems are either roof mounted or ground mounted. The mounting systems and securing methods are determined by type of roof, available space, structural requirements, etc.
How its Works
Step 1: Sunlight strikes the modules.
Within the solar cells, sunlight is converted directly into electricity. What happens is that the energy from the sunlight causes an electron to move into an excited state. This heightened activity separates that electron from the molecule it was bound to, and the flow of electrons is termed electricity. Solar cells are made in such a way that the electrons can only flow in one direction. Thus, the type of electricity that solar panels produce is direct current (DC).
Step 2: The direct current is carried to an inverter.
An inverter changes DC (direct current) into AC (alternating current)—the type of electricity we use almost exclusively to power our homes and businesses.
Step 3: The alternating current is integrated into your available power supply.
AC electricity flows from the inverter into the building’s electrical service gear, where it is drawn as needed into electrical loads throughout the facility.
Carbon dioxide and nitrous oxide are greenhouse gases (GHGs) and among the multiple pollutants that contribute to global warming and its associated health problems.
Reduce Poisonous Pollutants
Although electricity is a modern-day necessity, power production methods that rely on fossil fuels cause harm to our environment. Solar power is a clean and efficient renewable energy alternative. Photovoltaic systems generate solar electricity by turning photons from the sun into usable energy, without causing the release of carbon dioxide.
Generating electricity from fossil fuels produces nitrogen oxides (NOx), volatile organic compounds (VOCs), particulate matter (PM), carbon dioxide (CO2) and sulfur dioxide (SO2), among other emissions. NOx, SO2, VOCs and PM are related to various respiratory diseases, including asthma and lung cancer.
NOx are precursors to ozone and nitrate particulate matter. When inhaled, NOx can irritate and damage the cells lining the deep regions of our lungs.
SO2 is a precursor to sulfate particulate matter. When inhaled, SO2 irritates the upper regions of the lungs. It is also a major contributor to acid rain, which causes environmental damage to aquatic and forest ecosystems.
VOCs react with NOx to create ozone. Ozone causes damage to the cells in the deep regions of our lungs. It can lead to decreased lung functions, increased hospitalizations and increased mortality risks.
PM 2.5 is considered more dangerous than coarse particulate matter (PM 10) since it is smaller and can get deeper into the lungs. Exposure to both fine and coarse particulate matter has been associated with various respiratory ailments, decreased lung function, increased hospitalizations and increased mortality risks.