Finance and Regulations

The Entry–Exit System. The liberalization of the European gas markets started in the 1990s and lead to the current situation in which European transmission system operators (TSOs) typically operate under the so-called Entry–Exit system (Directive 1998/30/EC, Directive 2003/55/EC, Directive 2009/73/EC). The timing of this system is as follows: The TSOs have to publish so-called technical capacities at every entry or exit point of the their network. Afterward, gas traders can book capacities that are bounded above by the corresponding technical capacity. The booking is a capacity right that ensures that the trader can inject (as an entry customer) or withdraw (as an exit customer) balanced amounts of gas up to the booked capacity. The latter process is called nomination and the TSOs have to be able to transport all possible nomination situation as they are (via the bookings) conformal to the published technical capacities.