It should nevertheless not be forgotten that a simple carbon tax has much the same economic effect as a feed-in premium, all the while providing a simple and clear signal to all low-carbon technologies. This requires the provision of flexibility services in order to generate continuous matching of supply and demand. Between dispatchable back-up capacity, increased interconnection capacity, storage and demand-side management, energy markets need to be enabled to find the most efficient solution to provide system flexibility and ensure second-by-second matching of supply and demand.