An optimal coordination of seasonal energy storages: A holistic approach to ensure energy adequacy and cost efficiency.

• Introduction of a full-blown mathematical model of underground natural gas storage. • Presentation of an optimal management policy for underground natural gas. • Inclusion of water reservoirs in the optimal management policy. • Natural gas and power demands are tested during coincident peaks. • Energy production of the more polluting power plants is efficiently reduced. Significant challenges for system planners to formulate optimal policies for the use of energy resources require the use of novel analytical tools that efficiently incorporate existing assets nationwide. Depleted oil or natural gas fields, aquifers, mines, and salt caverns are geological formations that can be used to store natural gas. They are assets available in most of the OECD countries and are an alternative for system planners to incorporate. This paper presents an optimal management policy for the utilization of natural gas -in an underground facility- and water -in reservoirs- so that said policy determines when and how much natural gas and water should be stored and when they should be used. It aims to guarantee that primary energy resources -in the form of natural gas or water- are available in order to meet future demands under extreme weather conditions or a scenario of coincident natural gas and power peak demands. The policy is based on a full-blown mathematical model of the underground natural gas facilities that considers the most relevant geological characteristics. The model introduced in this paper guarantees that the policy is feasible. Numerical results prove that ignoring geological features leads to infeasible results. They also confirm that the adverse effects of having coincident natural gas and power demands can be mitigated if natural gas storage and water reservoirs are properly used. [ABSTRACT FROM AUTHOR]