Energy storage will play a pivotal role in providing the needed flexibility and offering balancing options to the integrated energy system. Greater deployment of energy storage is required at different scales, i.e. from low power and fast response solutions (< 1kW; <1s) to longer-term balancing needs for the grid (>1GW; hours to days and beyond). Large-scale and centralized energy storage can provide flexible bulk power management services for electricity, gas and heat commodities.