Efficiency Solar Panels

The record holder for efficiency among solar panels, one of the one way or another available on the market today, are solar panels based on multilayer solar cells developed by the Fraunhofer Institute for Solar Energy Systems in Germany. Since 2005, Soitec has been engaged in their commercial implementation.

The size of the photocells themselves does not exceed 4 millimeters, and focusing of sunlight on them is achieved by using auxiliary concentrating lenses, thanks to which saturated sunlight is converted into electricity with an efficiency reaching 47%.

The battery contains four pn junctions so that four different photocell links can efficiently receive and convert radiation with a specific wavelength from sunlight concentrated 297.3 times in the wavelength range from infrared to ultraviolet.

The researchers, led by Frank Dimirot, initially set themselves the task of growing a multilayer crystal, and a solution was found - they sprouted the substrates for growing, and as a result a crystal was obtained with various semiconductor layers, with four photoelectric subcells.

The growing process has turned out to be more complicated than is the case in the traditional production of silicon batteries, but the performance of new batteries has doubled. In addition, the cost of creating a system with a hub is lower than when creating conventional solar panels.

Multilayer solar cells have long been used on spacecraft, but now solar stations have already been launched on their basis in 18 countries. This is made possible by improving and reducing the cost of technology. As a result, the number of countries equipped with new solar stations will grow, and there is a tendency towards competition in the market of industrial solar panels.

In second place are solar panels based on three-layer Sharp solar cells, the efficiency of which reached 44.4%. Indium gallium phosphide is the first layer of the photocell, gallium arsenide is the second, indium gallium arsenide is the third layer. The three layers are separated by a dielectric, which serves to achieve the tunneling effect.

The concentration of light on the photocell is achieved thanks to the Fresnel lens, as with German developers, the light of the sun is concentrated 302 times, and is converted by a three-layer semiconductor photocell.

Research on the development of this technology has been continuously conducted by Sharp since 2003 with the support of NEDO, a Japanese public administration organization that promotes research and development, as well as the dissemination of industrial, energy and environmental technologies. By 2013, Sharp achieved a record of 44.4%.

Two years before Sharp, in 2011, the American company Solar Junction had already released similar batteries, but with an efficiency of 43.5%, elements of which were 5 by 5 mm in size, and the focus was also made with lenses, concentrating the light of the sun 400 times. The solar cells were three-junction based on germanium, and the group even planned to create five and six-junction solar cells to better capture the spectrum. Research is ongoing by the company to this day.

Thus, solar batteries made in combination with concentrators, which, as we see, are produced in Europe, Asia and America, have the highest record efficiency. But these batteries are mainly made for the construction of large-scale ground-based solar power plants and for the efficient power supply of spacecraft.

Recently, a record has been set in the field of ordinary consumer solar panels, which are available to most who want to supply them, for example, the roof of a house.

In the middle of autumn 2015, the company Ilona Mask SolarCity introduced the most efficient consumer solar panels, the efficiency of which exceeds 22%.

This indicator was confirmed by measurements taken by the Renewable Energy Test Center laboratory. The Buffalo plant already sets a production plan for every day - from 9 to 10 thousand solar panels, the exact characteristics of which have not yet been reported. The company already plans to supply at least 200,000 homes with its batteries annually.

The fact is that the optimized technological process allowed the company to significantly reduce the cost of production, while increasing efficiency by 2 times compared with the widespread consumer silicon solar panels. Musk is sure that it is his solar panels that will be most popular with homeowners in the near future.

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