  Renewable energy productions and electrification of mobility are promising
solutions to reduce greenhouse gas emissions. Their effective integration in a
power grid encounters several challenges. The uncertain nature of renewable
energy productions as well as stochastic consumptions of electric vehicles
introduce remarkable intermittency to a distribution grid and results in
bi-uncertain characteristics of both supply and demand sides. One way to verify
the secure grid operation within acceptable voltage and loading levels is to
assess its required flexibility considering possible boundaries of uncertain
variables. In this paper, first a comprehensive linear model of distribution
grid considering all pertaining constraints is presented. Then, a flexibility
estimation technique is proposed based on the feasibility study of the
uncertain space of photovoltaic power productions and load containing electric
vehicles. The proposed methodology uses grid monitoring data to determine grid
state and to model uncertain parameters. The model is applied on a real low
voltage (LV) system equipped with grid monitoring devices.
