The amount of electricity generated by a sIt is important to understand the project’s purpose and its use case by case.olar photovoltaic panel depends on some factors, such as PV panel technology, dimensions, type of installation, position, location and weather conditions.
PV Technology and Efficiency
The basic component of every photovoltaic panel is the solar cell, and over the years different PV technologies have been developed. Nowadays, there are 3 types of solar panels with different technologies available on the market, namely monocrystalline, polycrystalline, and thin film amorphous panels.
Monocrystalline PV panels are created from a single continuous crystal structure, made of silicon with purity level close to 100%. Since these solar panels have a higher power output, they also require the least amount of space compared to any other type of modules, making them the ideal solution when space is limited. The most efficient solar panels on the market today have energy efficiency ratings as high as 22%.
Polycrystalline PV panels are made with thin wafers, cut from a silicon block. Their manufacturing method is cheaper and, although they are less performing compared to monocrystalline panels, they have become the dominant technology in the solar PV sector. They are also more resistant to high temperatures. The energy efficiency rating of these type of PV panels ranges from 13% to 16%.
Thin film PV panels are made by depositing a photovoltaic substance like Amorphous Silicon, Cadmium Telluride (CdTe), Copper indium gallium selenide (CGIS), Dye-sensitized solar cell (DSC) onto a solid surface like glass. They work well in a wide range of conditions and better than other PV technologies in case of low irradiation and not optimal positioning (indirect irradiation). Thin film panels have reached energy efficiencies of about 9%.
The dimension of a photovoltaic panel is about 200×100 cm and it contains 60 or 72 cells in most cases. Nowadays the peak power output of a PV module varies between 250 and 350 Wp.
The peak power of the solar PV panel is the power output at Standard Test Conditions (STC) in laboratory, equal to 1,000 watts per square metre of solar light and 25 degrees of module temperature, equivalent to irradiation conditions at noon during a sunny day.
For example, a 300 Wp solar PV panel generates 300 Wh of electricity at standard test conditions.
Position and Location
The energy production of a solar PV panel depends on the radiation intensity, on the direction of the rays of sunlight that strike the photovoltaic module and on the ambient temperature. Consequently, the inclination, orientation and geographical position of the solar PV panel affect its efficiency.
At any given location, represented by its latitude and longitude, the photovoltaic panel power output is affected by tilt angle and azimuth angle. The maximum values of energy output are reached if the solar PV module faces south in case of fixed structure, and east-west if a solar tracking system is mounted. The best inclination depends on the latitude of installation of the PV system, but a medium value can be set to 30°.
Type of Installation
The energy production of a solar power plant depends also by the type of installation. Ground-mounted PV plants will perform better than rooftop PV systems because the ventilation is better and high temperatures negatively affect the efficiency.
In addition to weather conditions, there are also other factors that can decrease the power output of the module, like electrical problems, shadows, pollution and sand deposits (soiling), and potential-induced degradation reducing photovoltaic module performance.
Enerray, a leader in EPC and O&M for industrial and large-size PV systems, carefully selects the PV modules relying on certified suppliers and international forwarders, ensuring in this way the best price, reliability and cost ratio. Furthermore, Enerray can offer a 360° maintenance service, in order to keep the PV panels and the photovoltaic system perfectly efficient, thus ensuring top performance.