Unlike in vertically integrated power systems, where energy storage is coordinated with the rest of the system to minimize the overall generation cost [1], operations of energy storage in systems with electricity markets are driven by preferences of their owners [2]. The owners are typically profit-seeking entities that aim to collect the maximum profit possible for given system conditions. These preferences of the storage owners do not necessarily lead to the minimization of the overall generation cost in the system. Generally, merchant storage devices will provide services that can be monetized and that are most profitable. These include energy arbitrage, frequency regulation, reserve provision, voltage support, etc. [3, 4]. On the other hand, energy storage may be beneficial to the system in terms of deferred investment in transmission lines or generating units, reduced cycling of thermal units, reduced curtailment of renewable generation, etc. [5]. However, since energy storage does not always receive a payment for providing these services, they are merely consequences of an energy storage providing services for which it receives remuneration.

Chapter Contents:

• 4.1 Introduction
• 4.2 Energy storage in energy market
• 4.2.1 Energy storage as price taker
• 4.2.1.1 Deterministic model
• 4.2.1.2 Stochastic model
• 4.2.1.3 Robust model
• 4.2.2 Numerical example of energy storage as price taker
• 4.2.2.1 Deterministic optimization
• 4.2.2.2 Stochastic optimization
• 4.2.2.3 Robust optimization
• 4.2.3 Energy storage as price maker
• 4.2.3.1 Notations
• 4.2.3.2 Mathematical formulation
• 4.2.3.3 Linearization
• 4.3 Energy storage in reserve market
• 4.3.1 Policies enhancing energy storage flexibility
• 4.3.2 Generalized payment scheme
• 4.3.3 Dilemma: Trade energy or frequency regulation?
• Appendix
• References
• Further Reading

Inspec keywords: profitability; investment; power markets; energy storage

Other keywords: energy storage; reserve provision; profit-seeking entities; frequency regulation; electricity markets; merchant storage devices; deferred investment; energy arbitrage; generation cost minimization; renewable generation; generating units; thermal units; transmission lines; vertically integrated power systems; voltage support

Subjects: Power system management, operation and economics; Direct energy conversion and energy storage