Capacity and Energy Availability Markets: The Role of the Battery Energy Storage and Storage Systems (BESS)
An electricity system with a growing presence of renewable energy needs resources that can be made available when generation is insufficient or demand reaches high levels. Capacity mechanisms or markets aim to guarantee that firm power is available during peak demand, complementing the energy traded in the electricity market.
Unlike arbitrage, where value comes primarily from buying and using energy at different times, a capacity mechanism recognizes the availability of the resource to respond when the system requires it. The specific design, products, auctions, and requirements depend on current regulations.
Why can an BESS participate?
A battery can store energy beforehand and deliver it quickly and in a controlled manner. This capability makes it a suitable resource for providing power during critical periods, provided it meets the technical, measurement, communication, duration, and availability conditions established by the mechanism.
An ESS can operate individually or, when permitted, be integrated into an aggregated portfolio. For industrial or commercial customers, this opens the possibility for an asset initially installed for self-consumption or peak slugging to also participate in future capacity schemes.
Availability vs. Energy
The distinction is important. Energy expresses how long a certain power output can be maintained; availability indicates whether that power will actually be ready when needed. A high-power BESS with low energy capacity may not meet a long-duration requirement. Similarly, a battery used in other applications might not have the necessary state of charge.
The EMS must reserve capacity, plan for recharging, and coordinate the different services. It must also consider degradation, temperature, downtime due to maintenance, and any testing or penalty obligations.
Potential Benefits for Customers
· Diversification of BESS Value: Availability can complement the savings obtained through other applications.
· Better Asset Utilization: It allows for the use of power and capacity that would otherwise remain idle during certain periods.
· Preparedness for New Markets: A flexible architecture facilitates adaptation to future energy signals and products.
· Support for system security: Storage helps cover periods of scarcity and integrate renewable generation.
· Greater operational discipline: Continuous monitoring of charge status and availability improves asset management.
A project that must consider regulations
Participation is not automatic or guaranteed simply by installing a battery. It is necessary to verify the applicable framework, prequalification, minimum power, required duration, communications, and economic regime. Projected revenues should be evaluated prudently and should never replace a comprehensive technical and financial analysis.
It is also advisable to study how the capacity market interacts with backup power. Reserving energy for the system and maintaining autonomy for an internal emergency can compete for the same capacity. An appropriate strategy defines priorities and safety margins.
At Vector Energy, we develop modular and manageable BESS solutions, ready to combine current and future applications. A design based on real availability allows storage to become a more versatile energy asset, aligned with the evolution of the electrical system.
More information: sunvec.es/storage