In the FO universe, was his method for producing electricity seen as superior to Thomas Edison's?
By the 1950s, most direct current (DC) power grids had been replaced by alternating currents. (AC) The "War of the Currents" took place mainly in the 1880s and 1890s, and the benefits of AC power (which could transport electricity for hundreds of miles without losing power, while DC would do so after a mile) were widely seen. Thomas Edison died in the 1930s, Nikola Tesla died in the 1940s, so Nikola would have had much more time to convince the US government, especially without his competitor.
Seeing as the US government even went as far to adopt his power weapons, as others have pointed out, it seems safe to say that AC power had been triumphant in the Fallout universe, just as it was in ours.
I know Fallout loves archaic tech over modern tech, but you just can't say no to AC power, unless you want to jot a power plant every mile or so.