Relíquias ... ou talvez não

Nikola Tesla’s alternating current may have “won” the War of Currents at the end of the 19th Century, but the defeated incumbent—direct-current distribution, aggressively championed by Thomas Edison—endured. As historian of technology Thomas P. Hughes observed in his influential essay on the evolution of large technological systems, the War of Currents ended “not with victor and vanquished, but with the invention of devices making possible the interconnection of the two systems.” Remnants of DC power distribution kept performing their assigned tasks for decades as the AC grid thickened around them.

In fact, a few live on to this day. One of the best examples is in San Francisco, where 250-volt DC power still flows through underground and overhead cables across the city. These DC lines peacefully coexist with their AC counterparts; you can see this mix of currents straddling utility poles in the city’s South of Market district.

A rede de distribuição de corrente contínua foi a precursora na distribuição de energia eléctrica mas não sabia que ainda existia. A AC ganhou por permitir facilmente a transformação. A iluminação LED, tremendamente mais eficiente que a lâmpada incandescente, agradecia agora uma rede assim e a produção fotovoltaica também. Ironias.

A herança de Edison -os casquilhos E27 e E14 das lâmpadas - atravessam as duas gerações.