Abstract This paper presents a new available efficiency index (AEI) and then optimizes it in order to increase the number of hours the load is supplied while decrease the losses as well as expected energy not supplied in a smart grid. The effectiveness of the presence of energy storage system (ESS) along with renewable energy sources (RESs) that are associated with uncertainty is investigated on the availability of the smart grid. The combination of the ARIMA model with K-Means scenario reduction method is used to model the uncertainty of load. The feed-in tariff of all generations is considered to calculate the total profit of the system; also, the costs of carbon emissions and opportunity costs from non-production of carbon emission and non-payment of fossil fuel costs due to the use of renewable resources are considered. Also, the energy storage system and the pumped-storage hydropower are considered. In this paper, an improved multi-objective crow search algorithm (IMCSA) is used to find the optimal operation of a smart grid in order to increase the AEI and profit of the system. The proposed method not only can minimize the power losses of the smart grid but also can improve the availability, reliability and total profit of smart grid.