Valle Benoit

Valle Benoit

PhD student Team : ETAP

Thesis defended on 26.06.2017

Topic : "Modelling and optimisation of lettuce growth in a dynamic agrivoltaic system"

Abstract :

Agrivoltaics, a combination of photovoltaic panels and a crop on the same soil, was proposed in 1982 as a solution to land use conflicts. Launched in 2010 in Montpellier, the concept of combining fixed panels and various crops has demonstrated improved combined plot productivity due, in particular, to the acclimatisation of the crop in the shade. In this thesis, the fixed panels were exchanged for steerable panels during the day. The objective was to optimise the orientation of the panels to maximise the combined productivity of the plot without penalising the crop. To this end, the growth and development of lettuce was analysed under controlled conditions and in the field under different shading modalities using fixed or mobile panels. The mobile panels improved the combined productivity of the plot compared to fixed panels, while maintaining crop production under certain conditions. An ecophysiological approach based on plant development, its ability to intercept and convert radiation into biomass, revealed that shading modalities had little impact on leaf area development despite differences in accumulated biomass in relation to radiation transmitted to the plant. Changes in leaf development led to better utilisation of transmitted radiation when it was reduced. This work led to the modelling of the impact of panel orientation on lettuce biomass, allowing for the optimisation of panel control according to the climatic scenario and production objectives.

Supervisor : Thierry SIMONNEAU

Research project

As a CIFRE PhD student in collaboration with the company Sun'R, an energy producer, I am working on the innovative concept of agrivoltaic systems (Duprazet al., 2010). My thesis topic is "Modeling and Dynamic Optimization of Agrivoltaic Systems with Servo Trackers", and I am studying the ecophysiological responses of plants under an orientable photovoltaic structure.
In a context of conflicting uses of arable land between food production and energy production (biofuels, biogas, etc.), the association of these two systems on the same surface could be the solution. Previous work (H. Marrou, 2010-2013) has shown that the presence of photovoltaic panels on top of crops can, under certain conditions, produce agricultural yields comparable to field crops.
In this new thesis project, the photovoltaic panels above the crops are now orientable. By adjusting them according to the time of day, the climate or the phenological stage of the crop, it is possible to modulate the quantity and quality of solar radiation according to the needs of the crop.
In the framework of my thesis, I will have the task of modelling the ecophysiological responses of crops under photovoltaic panels according to their control. In this context, the phenomena of light-shadow transition and induction of photosynthetic activity will be studied under fluctuating conditions. The objective is to determine the best control of the panels to increase the yield in comparison with a control crop in the field.

http://www.sunr.fr/

 

University curriculum

Agronomic Engineer ENSAT (T10, AgroBioSciences Végétales)
Master 2 Research UPS III Toulouse (BioSciences Végétales)
End of study project at the LIPM (INRA-CNRS, Toulouse)