This paper provides a comprehensive analysis of the energy storage (ES) potential to mitigate technical impacts caused by the increased penetration of photovoltaic generators and electric vehicles in distribution networks. A Monte Carlo simulation strategy is first proposed to perform such study. ES impact on voltage magnitude/unbalance, conductor/transformer loading and technical losses is investigated in detail. Then, a study is carried out to determine whether dispersed (on customers) or concentrated (on transformers) ES allocation practices are more advantageous. Results show that ES generally has positive impacts on network operation, although its impacts can become negative once ES adoption rates become extreme (i.e., approaching 100%). Furthermore, it is found to be generally advantageous to install ESs within customers premises, rather than to install these devices on service transformers. This work is intended to support the development of attractive methods to integrate ES into distribution networks.