Luminescent solar concentrators starting from film-forming aqueous dispersions and water-soluble fluorophores could help the widespread diffusion of photovoltaics in the urban context. Windows, views, shelters, terraces could be examples where the aesthetic features of modern buildings is combined with the energy requirements of homes.
Patent Status
PENDING
Priority Number
IT102019000022068
Priority Date
25/11/2019
License
ITALY
Market
Nowadays, the most important techniques used to exploit solar energy consists of photovoltaic (PV) panels. The thrust in PV keeps lowering the price per unit of power generated as the technology becomes more and more widespread. However, current PV panels are opaque and guarantee maximum performance under direct light conditions. Among the possible solutions, luminescent solar concentrators (LSCs) are one of the most promising approaches to further decrease the costs of PV and facilitate the integration of solar-harvesting devices into buildings.
Problem
Typical LSCs are composed by high quantum yield organic or inorganic fluorophores that are embedded in optically transparent amorphous polymer plates or films with a good visible transparency and stability with time. Among polymer matrices, those based on commercially available plastics from fossil fules are the most utilized. From the perspective of a more sustainable fabrication route, recent approaches proposed the use of biobased polymers and materials from renewable resources. In connection with these findings, the use of waterborne polymer dispersions is proposed in this invention for the realization of thin film LSCs. Waterborne polymers are widely utilized in a range of applications, including paints and coatings, due to their unique properties and the advantage of being solvent free. They easily form a thin film over several surfaces including glass and dissolve a wide range of water soluble and dispersable fluorophores. The need of water as the only solvent, the mature coating technology and the materials low cost are all considered as means of boosting the LSC technology and its widespread use.
Current technology limitations
The diffusion of photovoltaics in the urban environment is often limited in cities with a high population density where the available surface is not sufficient to generate electricity useful for daily needs. The use of transparent and colored LSCs allows to integrate the aesthetic aspect of the devices with the generation of electric current. The LSC works by collecting sunlight from the dispersed fluorophore and concentrating it at the edges where the photovoltaic cells are positioned for the high efficiency light conversion into electricity. To date, LSC technology is entering the market and the solution proposed here would favor its wide diffusion thanks to the use of sustainable and low-cost materials.
Killer Application
Our technology and solutions
This technology allows the preparation of thin-film LSC with a large and colored but transparent surface starting from polymeric dispersions in water and from soluble fluorophores. The film made over transparent glass will generate electricity thanks to the photovoltaic cells connected to the edges of the device. LSCs having dimensions of 25×25 cm2 and 50×50 cm2 with 5 mm thickness and with maximum powers of 7 mW/cm² for each connected photovoltaic cell were obtained. The research team is planning to realise larger LSCs.
Advantages
This technology allows to obtain a low-cost luminescent colored panel consisting of a transparent glass coated with a fluorescent film obtained starting from an aqueous dispersion of a resin and a fluorophore with high quantum yield. Solar cells connected to the edges of the device enable the generation of electric current. This technology makes it possible to obtain electricity from windows, views, shelters and all available surfaces irradiated by the sun, combining the aesthetic aspect of the panel with the energy one.
Roadmap
The realization and installation of the panels connected to the photovoltaic cells and the preparation of even more performing water-soluble fluorophores than the existing ones will require further investments and an overall cost analysis also including the acquisition of photovoltaic cells of the desired dimensions and coinciding with the edge length of the panel will be investigated.
TRL
Team
