The Agri-PV concept refers to the combination of both agricultural and electrical productions on the same area. The presence of photovoltaic panels above a crop implies sharing of sunlight. The panels create shading on the crop and thus reduce the light available for plants. Previous studies has already been done to evaluate this association. The results are conclusive but optimization still needs to be done. It is essential to define strategies in order to determine the optimum orientation of the PV modules that are favourable for crop growth. First, a modelling approach is done in order to understand the interaction between the plant and the irradiation. Indeed, in order to adapt plant growth models, it is necessary to define new formalisms.