Despite the fact that microgrids are growing in popularity, their integration in distribution networks is problematic because of the omnipresent variability of renewable energy sources. New research focuses on viewing microgrids as having an active role in the system and providing additional services, such as the concept of low-carbon microgrid nodes. The paper presents a mixed integer linear programming optimization algorithm for determining the optimal size of the distributed generation unit and battery storage system based on operational savings and investment costs, as well as estimation of environmental benefits. The flexibility of the analyzed power node comes not only from its capability to store electricity in the battery banks but to optimally schedule flexible loads such as electric vehicles (EVs). Stochasticity of EV arrival and their state of charge are modeled daily and seasonally. The results show that active market signal-driven integration of such nodes is still not feasible without incentives. But as additional services start creating profits, the gap to feasibility will become smaller.