For decades, Thomas Edison's direct current (DC) electrical systems quietly powered American homes and businesses. While Nikola Tesla and George Westinghouse are often credited with pioneering the alternating current (AC) systems that came to dominate the electrical grid, Edison's DC systems were actually powering many buildings long before AC became popular. This article explores how Edison's DC technology provided electricity to customers for years through local grids and isolated power plants before eventually being surpassed by AC systems.

Edison Gets an Early Start with DC Power Distribution

Thomas Edison built the first DC power plant and distribution system in New York City in 1882, just a few years after he invented the first practical incandescent light bulb. This system supplied DC electricity to homes and businesses within one square mile of the Pearl Street Station in lower Manhattan.

The key innovations that enabled Edison's DC system were:

Within a few years, small Edison DC systems were operating in cities across America, providing electricity to downtown buildings and wealthy homeowners.

DC Power Spreads Locally Through Small Grids

During the 1880s and 1890s, small DC power grids emerged in population centers across America. These were relatively small, insular grids serving nearby buildings with Edison's direct current system.

Some key examples include:

These small DC grids served nearby buildings but did not interconnect into larger regional networks. But for many businesses and wealthy homeowners in urban areas, Edison's DC systems brought the wonders of electric lights, motors, and appliances during this period.

Isolated DC Plants Power Remote Mines and Communities

Not only were small DC grids spreading locally, but isolated DC power plants also brought electricity to remote areas. Throughout the 1880s and 1890s, stand-alone DC generating plants popped up at mines, mills, and villages across America.

Some examples include:

These isolated plants could transmit DC power over short distances, bringing electric illumination to rural towns and key industries.

The War of the Currents - Tesla and Westinghouse Promote AC

The story changes in the 1890s when Nikola Tesla partners with George Westinghouse to promote an alternating current system. They claimed AC was superior for transmitting electricity over long distances.

Edison fiercely defended his DC technology and a battle of "the currents" ensued. But by the late 1890s, AC started to gain traction as Westinghouse won contracts to build regional AC grids.

AC could transmit power hundreds of miles, while DC lines were restricted to just a couple miles before the voltage dropped. This gave AC the advantage for servicing larger areas.

The Slow Demise of DC in the Early 1900s

Even after AC systems began spreading regionally in the early 1900s, Edison's DC technology continued powering thousands of homes and businesses connected to local grids or isolated plants.

But as AC networks expanded, DC slowly lost ground:

So while AC was clearly the future, the transition took decades. Many Edison DC systems powered buildings in areas without AC service well into the 1920s and 1930s before finally being retired.

DC Makes a Comeback in Modern Times

Interestingly, DC power has made a comeback in recent decades with applications like:

These all run on DC. While AC dominates long-distance transmission, DC has found a niche in modern electrical systems.

So while AC ultimately won the war of the currents, Edison's DC technology powered thousands of American homes and businesses for decades before fading away. The story of electricity pioneers like Edison and Tesla is filled with competition, intrigue, and unexpected twists!