COSMAGREEN · COating for SMArt GREENhouses

COating for SMArt GREENhouses

The proposed work aimed to increase the crop of greenhouses by implementing a fluorescent coating to the ceiling of the greenhouse. Plants do not harvest the whole solar spectrum equally at the different wavelengths. They indeed reflect green more and absorb dominantly red & blue thanks to the chlorophylls a-b. That’s why we see the plants green. Figure 1 illustrates that the solar spectrum is actually not optimized for energy conversion However, incoming solar spectrum can be modified in order to shift less efficient wavelengths to more efficient one (like green to red) using fluorescent pigments or phosphors. There are various experimental studies that show implementation of fluorescent coatings increases the overall crop amount. In our previously published paper, we attributed the crop growth of these experimental studies to the diffusion of light rather than spectral amelioration. Because, regardless of the incoming light direction, phosphors emit the light isotropically, which results in waste of approximately 50% of the remitted light that reflects to the space. This phenomenon is illustrated at Figure 2(a). Greenhouses are structures that have been historically designed in order to protect fragile plants such as vegetables, flowers or fruit trees from the climatic contingencies (like freeze). They minimize the effect of climate, short or long term, and aim to maintain the plants growing inside in optimal conditions. With the development and emergence of new technologies and ideas, greenhouses can be engineered to present novel features. One of these is to improve the greenhouse lighting to significantly enhance the plants growth. Note that this proposal addresses 2 of the UN sustainable development goals (2: zero hunger, 12: responsible consumption and production) as well as the food security societal challenge of Horizon 2020 program and has therefore an important economic and societal potential.

Data: CORDIS, © European Union