What key concept defined the rivalry in the "Battle of the Grids"?

The rivalry in the "Battle of the Grids" fundamentally revolved around the competing AC (Alternating Current) and DC (Direct Current) power systems. During the late 19th century, two primary forms of electricity were being promoted: Tesla's AC system and Edison's DC system.

AC power systems became the preferred method for transmitting electricity over long distances due to their ability to use transformers, which allow voltage levels to be easily altered. This made it more efficient for large-scale power distribution. Edison's DC power, while innovative, was limited in its practical application for long-distance transmission because it could not easily change voltage levels, resulting in substantial energy losses over distances.

The competition between these two systems was not just a technical disagreement; it also involved business strategies, public opinion, and the foundational setup of electrical infrastructure. Ultimately, AC emerged victorious, leading to the broader adoption of AC power systems we see today, which laid the framework for modern electrical grids.

The other options pertain to aspects that have influenced the electrical industry over time but do not encapsulate the central conflict that defined the "Battle of the Grids." Battery storage systems, renewable energy sources, and governmental regulations are all important factors in the evolution of energy