Photovoltaic panels on two sides

Technology of PV panels reversible

Photovoltaic technology has gradually developed over the years, improving the products and trying new forms and materials to make the most of the energy of the sun.
Only recently, however, it was thought one of the most obvious solutions: using the dark side of the panel, that is not directly oriented towards the sun.

The photovoltaic panels with two faces have the characteristic of having two faces of sun exposure, thus managing to ensure a yield of 50% even in conditions of low irradiance.
So we can say that this type of panels allows to increase to double the production of electrical energy, compared to the traditional types.

The increase is not obtained through particular modifications to the structure, the shape or the materials used, but simply increasing the surface area of exposure to solar radiation, allocating for this purpose also the one that normally would remain in contact with the roof or the cover.

The studies are set out from the lower part of the traditional photovoltaic panels: it remains, in general, raised from the top on which they are placed, both to maintain the proper inclination for the panels, and to ventilate them.
However, this position means that they are hit by the sun glare, and so on a lesser extent, but still collect a certain energy, which should not be wasted and can be exploited.

Manufacturers of solar panels on two sides

The development of the dual panel technology, started from bisolar, an Israeli company active in the field of renewable energy, which has developed in particular the issue of the exploitation of the reflected light, specializing in the production of these panels.

According to the company, with the panels that use reflected sunlight, we can increase the yield from 10% to 30%, and in the case of panels placed vertically (such as those that can be found along fences) you can get a yield of 50%.

The rear of the panels is carried out using the boron in place of aluminum, because the latter is only able to refract the light radiation and not to absorb it.

The production costs are also low, taking into account not only higher productivity, but also the use of materials other than silicon, more expensive and polluting.

The technology was presented for the first time during the Intersolar Europe in Monaco in 2012, but the first realization was made in Japan, with a plant of 730 kW.

In Italy, the bifacial solar cells are produced by MegaCell, a start-up founded by Franco Traverso, who at the time was also the founder of the Helios Technology, which he later sold in 2008.
The company also holds a patent that allows it to produce at a lower market price. In fact the cells are made by integrating a normal production line with only two additional processing steps.

The Bison bifacial cells in monocrystalline silicon N-type are very high efficiency and have been developed through a collaboration of the company with the Research Institute of the German ISC Konstanz.
Unlike the cells P-Type, these are said to zero LID. The LID (acronym for Light Induced Degradation) is the phenomenon in which after installation and then after exposure to the sun for a few days, the cells deteriorate and they see their power reduced by about 2-3%. With the Bison cells this phenomenon does not occur.
They are not even subject to the effect PID (Potential induced degradation), due to loss of isolation and reduction in longevity of a cell.

Each module consists of 60 cells Bison N - Type and allows to considerably increase the production of electricity, acting as a valid alternative to the use of fossil fuels.
Moreover, the company has to study a new type of panel able to guarantee a life of 50 years, thus making it even more convenient the use of photovoltaic technology.

The modules made with these cells have a wide range of applications, although, of course, the best results are achieved when it is possible to better exploit the bifacials.
With a reflective surface such as grass, these cells can reach an efficiency of 21.8%, while snow on the value increases up to 38%. The same result can be achieved by painting in white the surface of the bottom of the panel.

There are also situations in which the benefits of this type of cells can be exploited to the full as in the installation of fences oriented east - west.