Abstract
In this paper, we focused on natural gas suppliers' contracts, in which clauses (provisions) on minimum quantities of outputs are imposed over some period of time (e.g., a year, a day, or an hour). We developed two mathematical models to manage the portfolio of take-or-pay contracts. The first model deals with all of the constraints related to the existing inhomogeneous clauses, and it is used to avoid undesirable penalty payments on some contracts and excess payments on others. The second model extends the first model to support power plants in meeting electricity demands, while taking gas from the point of delivery and fulfilling the contract's specifications.
•A mathematical approach based on goal programming to manage a portfolio long term natural gas contracts.•Homogenization of contract clauses for a better management.•Better use of resources to generate electricity at the least cost.•Avoid misuse of flexibility or imposed quantities as stated in contracts.