What is the importance of reactive power reserves in the transmission system?

Reactive power reserves play a crucial role in maintaining voltage levels and ensuring system stability within the transmission system. Unlike active power, which performs the actual work in a system (such as lighting a bulb or turning a motor), reactive power is essential for managing voltage levels throughout the grid.

When reactive power is adequately supplied, it helps to support the voltage necessary for the efficient operation of the transmission system. If reactive power is insufficient, voltage levels can drop, leading to instability, which can cause equipment to malfunction or result in a broader system failure. By providing reactive power reserves, utilities can better respond to fluctuations in demand and unexpected changes in generation, ensuring that voltage remains within acceptable limits for the stability of the grid.

Other choices relate to different aspects of power systems. For instance, while reactive power does impact voltage, it does not directly contribute to the efficient long-distance transmission of electricity or reduce environmental impacts. Additionally, reactive power doesn’t inherently increase the capacity of transmission infrastructure; rather, it ensures that the existing infrastructure can operate reliably and effectively. Therefore, the importance of reactive power reserves lies primarily in their ability to maintain voltage levels and system stability, which is critical for the overall reliability of the electric grid.