The stand-alone microgrid with renewable energy sources(RES)integrated is considered one of the best solutions to provide electricity supply for small islands

but exorbitant investment barricades its application. For this reason

micro-pumped storage(MPS)is used as the energy storage system(ESS)for islands with good geographical conditions

and deferrable appliances are treated as virtual power resource to take part in the planning and operation. Household acceptance of demand response is indicated by the demand response participation degree(DRPD)

a capacity configuration optimization model is proposed with wind/solar/pumped storage and the demand response of household appliances in island microgrid taken into account. The particle swarm optimization(PSO)algorithm is used to get the optimal sizing of all major devices. The results of case studies demonstrate that the proposed method is effective

and demand response of deferrable appliances and the application of MPS can significantly reduce island microgrid investment. An investment sensitivity is analyzed on the total load

the deferrable appliance load and the water head of the pumped storage system.