The Construction Unit at Tecnalia (in conjunction with the University of Cantabria) has taken part in the Sunglass project, the aim of which is to develop a new building product. This involves a glass that augments the efficiency of photovoltaic solar systems, in such a manner that it boosts having more renewable energy in the construction sector.
The term "photovoltaic" literally means "light-electricity". This technology arose in the 1950s and currently has great possibilities of making contributions in the transition towards sustainable development in the building sector. To this end, the challenge for the Sunglass project is to boost the use of photovoltaic solar energy by means of increasing the performance of the currently existing solar panels (their performance goes up to 15 % now).
Research carried out to date has focused on modifying the semiconductor material to make use of a greater part of the solar spectrum. Nevertheless, the Sunglass project puts forward an alternative approach, involving the "conversion of frequencies" phenomenon — based on absorbing photons of certain frequencies and emitting another range of frequencies.
Study on photoactive compounds
Various photoactive compounds were investigated for the project. The objective was to determine their capacity to absorb high-frequency radiation in order to subsequently emit it at ranges more effective for solar cells, as well as the possibility of implementing these materials in the glass coating of solar panels. These compounds were used to develop the special glass for these photovoltaic applications. In this way, substituting the current glass of solar panels by the new product, an increase in energy efficiency was obtained.
By means of the "conversion of frequencies" produced by the glass, the radiation incident on the solar cells is more effective and gives rise to a significant increase in their efficiency (about 2-3 %), and which will have huge repercussion in the building industry.
This new technique will boost the production of clean energy without acoustic contamination and will avoid greenhouse effect gas emissions, besides being able to be used as a complement to other energy sources and provide great flexibility in its applications.