The transition to renewable energy sources is a significant milestone in the pursuit of a more sustainable energy future. However, this progress is not without challenges. The intermittency in solar and wind energy sources creates moments of excess and shortage of electricity, a problem that can be effectively addressed through the implementation of large-scale energy storage systems.
Batteries can be ‘co-located’ in solar plants and wind farms, playing a crucial role in stabilizing the electrical grid. During periods of high production, the surplus electricity, beyond the capacity to inject into the grid, is stored in these batteries. When there is availability in the grid, and production cannot meet the demand, the batteries come into action, providing supplementary power. This action is essential to ensure a continuous and stable electricity supply.
In addition to storage, ‘co-located’ batteries are multifunctional. They also have the ability to regulate the frequency of electricity flowing in the grid, providing a crucial control element for the stability of the electrical system. In adittion, they can mitigate abrupt fluctuations, ensuring a smooth transition between demand and production peaks.
On the other hand, there is also the possibility of installing large “stand-alone” equipment that can play a crucial role in the stability of the electrical system. These units are independent of generation plants but are directly connected to the electrical grid. In emergencies, such as a sudden increase in demand, the batteries come into action, providing instantaneous energy until regular production can be adjusted.
These batteries can be strategically positioned at critical points in the grid, ensuring a quick and effective response in crisis situations. This immediate response capability is essential to prevent interruptions in electricity supply and maintain grid stability.
In some countries, system services are critical components to maintain the stability and reliability of the electrical system, namely:
Frequency Regulation: This service is responsible for keeping the frequency of the electrical grid within acceptable limits. In case of fluctuations, battery operators can provide or absorb energy to stabilize the frequency.
Capacity Reserve: Involves the immediate availability of additional capacity in case of unexpected peaks in electricity demand or sudden failures in generation.
Demand Response: Involves adjusting electricity production or consumption in response to market signals or unexpected events to maintain the balance between demand and production.
Voltage Management: Ensures that the voltage in the electrical grid stays within safe limits, even in situations of variations in demand or production.
Toward an attractive and sustainable investment in batteries, it is crucial to establish a clear and effective regulatory framework. This includes defining fair tariffs for the services provided by batteries and ensuring that investors receive adequate compensation for their role in grid stability.
Looking beyond our borders, we can observe inspiring examples in other countries. Through favorable policies and financial incentives, some countries have driven the adoption of large-scale batteries.
The implementation of such systems in Portugal is feasible and can be beneficial for the national electrical system. With the increasing integration of intermittent renewable energies, such as solar and wind, the need for system services becomes increasingly important to ensure grid stability.
However, it is crucial to consider the specificities of the Portuguese electricity market and tailor the compensation model to local characteristics. This may involve consultation and collaboration between regulators, grid operators, and investors in storage and energy production solutions.
Implementing system service compensation in Portugal would not only strengthen the resilience of the electrical grid but also open up opportunities for investments in the energy storage sector, contributing to the transition to a cleaner and more sustainable electrical system.
Opinion article by Miguel Subtil, Managing Director of Átomo, published in Ambiente Magazine on November 15, 2023.
