One of the main tasks of the Smart Materials project was completed last year. Greenhouse simulation models were used to explore the potential effect of smart covering materials with switchable optical filters on microclimate, use of resources and crop performance.

Until recently, the only way to modify the amount and quality of light reaching the crop in a greenhouse was to use temporary coatings or screens. Three main groups of filters were identified and simulated: filters reflecting both PAR and NIR radiation, filters selectively reflecting only the NIR part, and filters reflecting the FIR spectrum.

Different climate regions and types of coverings were analysed to factor in a range of scenarios. The results highlight a significant potential improvement in microclimate and yield associated with the use of switchable optical filters for all the analysed climates, even if the optical properties are less than ideal.

For some of the simulated filters there are other alternatives available which perform equally well (thermal/energy saving screens). Further research is needed to analyse the technical and economic feasibility of these theoretical filters.