This paper presents a probabilistic approach to evaluate the effectiveness of Volt-Watt control embedded in most inverters for voltage regulation in a low voltage residential feeder with high shares of photovoltaic generation. Monte Carlo Simulation is applied to consider the inherent uncertainties from residential demand and solar generation using real historical data. The distribution network used is representative of a residential condominium in the city of Belém, Pará. Two irradiance scenarios are considered in simulations, and results show in both cases Volt-Watt control can effectively reduce the probability of overvoltage problems and technical losses.