Abstract:

The demand for natural gas rises constantly and it is currently third most important energy source in the world with a share of 23.4%. In Croatia, natural gas is the second most important energy source and continuous growth of natural gas consumption is predicted until 2027. The purpose of this paper is to provide a description of natural gas market in Croatia and analyse its trading system in order to propose a solution which could minimize or fully eliminate the problems of transmission system imbalance influenced by natural gas orders. Natural gas trading in Croatia is conducted on the trading platform and is based on the balance groups model. The manager of each balance group put the order proposed for the balance group’s customers (so called nomination) to transmission system operator and thus reserving capacity of transmission system. Gas from transmission system goes to distribution systems and reach the final consumers. If the real consumption differs from the order, transmission system might become unstable and need to be balanced. The balance group manager has a limited option to trade surpluses or shortfalls and, if this is not reached, balancing of transmission system is needed. The costs of balancing (penalties) must be paid by the balance group manager. This research showed that the difference between nominations and actual consumption rises when the time period is narrowed (from year to hour). To avoid penalties, we are currently trying to develop a simulation model that will test the ability of distribution system to accumulate that amount of natural gas which represents the difference between nominated and consumed amount of gas. This paper represents only a preliminary research, conducted before testing the simulation model.