Stricter emissions control and the increasing pressure for a common European energy market have stimulated new comprehensive methods for the estimation of national CO2 emissions that capture trade balances and introduce life-cycle implications for various sectors and products. In this study we adopt a new estimation framework for national electricity sector emissions which takes into account the cross-border electricity trade. Most importantly, we consider a novel aspect of how can utility-scale energy storage increase its value in its effort to serve the purpose of large-scale integration of renewables and system flexibility. For different levels of energy storage we assess the potential to prevent electricity trade flows from countries with higher CO2 emission factor to countries with lower CO2 emission factor. Optimum assessment of energy storage capacity in European countries is looked at from the viewpoint of maximum CO2 emission savings and the technically realizable pumped hydro storage at the national level. This is associated with the break-even CO2 price that can marginally support new investment in this domain. Our results show that the use of grid-scale energy storage could provide the framework for a fair burden sharing of emissions' allocation in Europe and support a flexible and resilient energy supply system. (C) 2015 Elsevier Ltd. All rights reserved.