Antireflective (AR) coatings are used to decrease the reflection of light between two interfaces with different refractive indices. They are tailored to minimize reflectance at specific regions of the electromagnetic spectrum, such as infrared (IR), visible, or ultraviolet (UV) light. PV manufacturers would like to apply an AR coating to the superstrate glass of their […]

A PV module’s performance and aesthetics can be altered with scratches. For instance, when thermoplastic frames are scratched, they are not only aestheti­cally unpleasing, but their electrical resistance can be compromised if the thermoplastic is an insulator for electrical conduits. This same design struggle has occurred in a number of industries. In this instance, it […]

Even during the PV industry’s infancy, soiling was viewed as a large technical obstacle for profitability. In the early 1980s, the Jet Propulsion Laboratory (JPL) began surveying materials as potential candidates for antisoiling coatings. The only formulations that showed promise were developmental formulations supplied by 3M (St. Paul, Minnesota) and Dow Corning (Midland, Michigan). Willis […]

Scientists try to predict soiling by characterizing a surface’s wettability. Wettability describes how a liquid spreads across the surface. The contact angle formed between the substrate, liquid, and air interfaces is a standard wettability metric. When water is used as a dispensing fluid, the contact angle can be used to measure hydrophilicity. An image of […]

It is a priority for PV manufacturers to predict performance degradation from laboratory measurements rather than assume the expense of field test­ing in multiple environments. PV manufacturers want to simulate climates with the highest number of PV installations. These include polar, temperate, arid, and tropical climates. Each of these climates has a characteristic soil type […]

Dirt, dust, soot, and animal excrement can build up on module’s surfaces hindering light transmission and, subsequently, the module’s performance. PV modules are typically elevated on roofs or trackers out of daily human traffic. As a result, they are not easily accessed for cleaning. Soiling decreases the transmission over all wavelengths, but the highest amount […]

6.1 Emerging Polymeric Applications Because photovoltaic (PV) cells will ultimately reach a technological limit, scientists have investigated alternative packaging materials to improve effi­ciencies. Antisoiling, antiscratch, and antireflective coatings can be exter­nally applied to PV modules to increase the concentration of incident light and offset diminished performance due to environmental exposure. This is a growing field […]

In recent decades, PV companies have experienced an inversion in their vari­able cost structure. In 1978, the front end dominated variable costs for many companies. For instance, processing polycrystalline silicon (35%) and its con­version into cells (26%) constituted 61% of the costs. It was projected that by 1986, the back end had become the largest […]