What role do surge arresters play in substations?

Surge arresters are crucial components in substations primarily designed to protect electrical equipment from voltage spikes, which can occur due to various factors such as lightning strikes or switching operations. When an overvoltage event occurs, surge arresters act by diverting the excess voltage away from sensitive equipment, effectively limiting the surge that reaches the equipment. This protective mechanism prevents damage that could arise from surges, thereby ensuring the reliability and longevity of the electrical system.

The other options do not accurately describe the main function of surge arresters. While improving energy efficiency or transformer lifespan can be indirect benefits of effective surge protection, these components do not primarily serve that purpose. Additionally, surge arresters do not facilitate communication within a substation; their primary focus is solely on protection against overvoltage conditions.