The idea of electronic dance music was in the air from 1975 on. Released as disco 12" records in the U.S., cuts like Kraftwerk's "Trans-Europe Express"(1977) and "The Robots" came after Giorgio Moroder's electronic productions for Donna Summer, especially the 1975 "I Feel Love." This in turn had a huge influence on Patrick Cowley's late '70s productions for Sylvester: synth cuts like "You Make Me Feel Mighty Real" and "Stars" were the start of gay disco.
Much has been written about Kraftwerk being the originators of house. While this is a nice idea, the truth is far more complex. Due to the relatively cheap availability of drum machines and synthesisers from Japanese companies like Roland (the feted 808 and 909 drum machines both originated in Japan) something was bound to happen anyway.
See also: Ron Hardy, Techno, Electro, Shep Pettibone, Electrifying Mojo, Arthur Baker, 1982, keyboards