Why Countries Use Different Power Frequencies

When you travel to another country, you may need to pack a converter or adapter so that you can safely use your devices in foreign outlets. Everyone from the vacationing tourist to the scientific research technician needs to adapt to these differences in electrical frequencies. But if you’ve ever wondered why countries use different power frequencies, the answer goes back to a name most of us know: Thomas Edison. Read on to learn more!

Edison and Tesla

In the olden days, the United States used 50hz DC power because that’s what Thomas Edison thought was the safest and most effective. But Nikola Tesla began experimenting with 60hz and AC power that most of the US would come to use. The feud between these two men grew to such extremes that Edison once electrocuted an elephant to try and showcase the dangers of AC power at that level. While 60hz eventually became the norm in America, it wasn’t as quick and easy a change as flicking a light switch.

European Countries

Despite the controversy in the US, most of Europe during that time used the 60hz system. So when you’re looking at why countries use different power frequencies, a lot of the time, it’s a matter of accessibility.

Many places in the US continued to use 50hz because of a partnership with a German company, AEG, that sold power grids and systems that used the 50hz system. However, because AEG was once a monopoly, many European countries began using their systems after World War II. This is why Europe transitioned to the 50hz system they use today.

Essentially, Europe and the United States swapped their power systems over the decades. Because of this, using devices from other regions such as Europe is one example of when you would need to use a frequency converter.


Unlike many countries, which have a primarily universal power frequency, Japan uses both the 50hz and 60hz systems depending on which side of the country you’re in. This is because major cities in Japan imported their electrical systems independently of one another. Some major cities imported systems from AEG in Europe; others went with US systems. At a center point, Japan has four separate frequency converter stations to help keep things running smoothly throughout the country.

By Dianne Pajo

Dianne Pajo is a writer based out of the Chicagoland area with a passion for music, combat sports, and animals. She enjoys competing in amateur boxing and kickboxing, but in her other leisure time, you can find her performing music around the city. She is also a dog mom of 2.