This kind of market structure is typical of pre-liberalisation energy sectors in most countries, including the six SEE economies. For example, OECD member countries’ experience of energy market liberalisation is that markets for electricity that are co-ordinated and integrated across borders into regional markets, deliver consumer benefits, including more competitive prices and greater supply security (IEA, 2005). More recently, it has become clear that regional integration of electricity markets is required to achieve least-cost emissions reductions (IEA, 2014a). The potential gains from balancing resources, if they are shared effectively among the economies, include increased technical possibilities for balancing capacity provision, lower overall balancing costs, and alignment of the costs of balancing service provision with the costs of making them available (ECS, 2014).