Module, photovoltaic cell requirements

A solar photovoltaic system contains, in addition to solar cells and module(s), an array structure to support the modules, power-conditioning circuitry for control and modification of the output, and a means of storing energy if required. All elements beyond the module are referred to as balance-of-system (BOS) components. The cost of BOS items is nominally about equal to the cost of the PV module. However, the BOS fractional cost contribution can vary from one- to two-thirds of the total installed cost of a system, depending on application. 

For metal, dielectric and semiconductor films fabrication, optical and silica glass are popular substrate materials because of their availability, cost-effectiveness, and inert character, i.e., they are stable in the required temperature range for common photonic, optoelectronic and photovoltaic applications, they do not chemically react with the prepared films, and the hard plane surface makes the formation of optically smooth thin films fairly easy. Generally, it is preferable to form films by a simple, low-temperature, inexpensive and environment friendly method. Sol-gel technique and thermal evaporation is found suitable for the preparation of film parts of efficient solar cells [1], emitters, transformers [2], detectors and modulators of light [3], as well as optically stimulated luminescence dosimeters [4]. Here, we present the experimental data on the resistance to high-power optical and ionizing irradiations of the undoped components of film compositions with nanociystais. 

Given that a suitable semiconducting electrode material can be found, what advantages can a PEC system offer compared with an electrolyzer driven by a module of photovoltaic (PV) solar cells With a PEC system at an estimated theoretical efficiency of 25% (corresponding to 1.7 eV), the current density will be around 20mA cm As seen from Figure 4.3, the overpotential rj++ri ) falls off rapidly below 30 mA cm Assuming that the overpotential for water electrolysis is the same in both a PEC cell and an electrolyzer, it follows that the required band gap of the chosen photoactive semiconductor in the PEC cell can be kept as low as 1.6-1.8 eV. Compared with an electrolyzer driven by a solar PV module, each PEC cell... 

Encapsulants are necessary for electrical Isolation of the photovoltaic circuit. They also provide mechanical protection for the solar cell wafers and corrosion protection for the metal contacts and circuit interconnect system over the 20-year design life of a photovoltaic array. The required components Include the solar cell circuit, the rigid or structural member, the pottant, and the outer cover/insulator. Surface modifications may be needed to develop strong, stable bonds at the Interfaces in the composite. If the module is to be framed, edge sealants may also be required. The functions of the Individual components and the performance requirements as they are now known are described. Costs are ccmipared where possible and candidate materials identified. 

A few years ago, most terrestrial photovoltaic (PV) modules were assembled by casting the cells in a transparent silicone substance, using a metal substrate for support. When this approach was reviewed by the Flat-Plate Solar Array Project (FSA), development was begun on new materials that would reduce the cost and quantity of material required for encapsulation. 

Solar panels used to power homes and businesses are typically made from modules holding about forty cells. A typical house requires an array of ten to twenty solar panels to provide sufficient power. The panels are mounted at a fixed angle facing south, or they can be mounted on a tracking device that follows the sun, allowing them to maximize solar energy capture. For lai e electric facility or industrial applications, hundreds of solar arrays are interconnected to form a lai e utility-scale photovoltaic system. 

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