| Improved Efficiency of PVT Collector Anka Trajkovska Petkoska1; Ilija Nasov2; 1ASSOC. PROF., Veles, Macedonia (Former Yugoslav Republic of Macedonia); 2CEO PLASMA, Skopje, Macedonia (Former Yugoslav Republic of Macedonia); PAPER: 293/AdvancedMaterials/Regular (Oral) SCHEDULED: 17:50/Thu. 24 Oct. 2019/Leda (99/Mezz. F) ABSTRACT: The increased concern for global warming, climate changes and rising energy prices has led to a high level of political and social motivation for energy-efficient, eco-friendly and sustainable energy production. Solar energy has the potential to play a leading role in renewable energy solutions. It addresses the energy problem from human health and environmental perspectives to economic perspectives. Moreover, solar energy is capable of satisfying both the electrical and thermal needs of industries and households by means of photovoltaic (PV) and solar thermal (ST) technologies respectively or by using hybrid photovoltaic-thermal (PVT) collectors. Actually, PVT collectors incorporate both thermal and electrical energy generations that can be used as a cooling system for the PV system in order to enhance the electrical energy efficiency and, at the same time, produce thermal energy that can be used in other applications (e.g. for water heating, space heating, etc.). This integration of PV and thermal collectors does not only enhance PV effectiveness; it also produces more energy for a certain area than a singular PV cell or solar collector alone. The combination of these systems offers few benefits such as: (i) An increase of photovoltaic cell effectiveness (cooling through the solar thermal system), (ii) A reduction in space utilisation (attractive in the case when the available roof surface is limited), (iii) Replacement of the roofing material with the PVT system that can reduce the payback period, (iv) Reduction of greenhouse gas emissions by utilisation of renewable energies. PVT collectors have become an important research topic in the last four decades and have attracted many interests. Research on PVT collectors started with the main focus on increasing the PV efficiency. In this work, the authors present a few innovative steps that increase PVT efficiency as well. Namely, low soiling coating on the top cover glass of PVT assembly enables the system to have a clean surface for a longer period of time. It extends the time efficiency of this system because the top glass transmittance is not decreased over a certain time period and consequently, produces more energy compared to PVT systems that do not have such a coating. This protective coating could offer a combination of antireflective, antistatic, anti-corrosion and, in some cases, photocatalytic effects. The second innovation is related to usage of thermal conductive adhesives that bond together the PV module to the ST’s absorber. Namely, the PV backsheet is directly adhered to the Al absorber surface and the heat taken from the PV module is transferred towards the ST absorber. To enhance the heat conductivity in this system, thermally conductive dopants were used. A variety of adhesive systems were investigated and the best one was selected. Finally, ST absorbers’ pipes are protected with inner anti-corrosive coating, so the PVT system could be considered for usage in salty (corrosive) regions or in direct water-circulation systems (e.g. for pool heating). This project is supported by the Fund of innovation and technology development of R. North Macedonia, 2018-2020. |
