Brazil vs. Japan: Why is the Japanese electrical system one of the most curious in the world?

While Brazil and Japan face off this Monday (29) in the Round of 16 of the World Cup, a little-known fact outside the electricity sector draws attention: the Asian country operates one of the most peculiar electrical systems on the planet.

Unlike most countries, which use a single electrical frequency throughout the national territory, Japan maintains two distinct operating standards. The eastern region of the country operates at 50 Hz, while the western region operates at 60 Hz, requiring the use of converter stations to allow the exchange of energy between the two regions.

The division dates back to the late 19th century, when Japanese companies imported electrical equipment from different suppliers. While Tokyo adopted German 50 Hz equipment, Osaka opted for American 60 Hz machines. More than a century later, this historic decision continues to influence the operation of the Japanese electrical system.

Renewables are gaining ground, but thermal power plants still lead.

Despite advances in the energy transition, Japan still relies heavily on thermal power plants to ensure security of supply. According to official data from fiscal year 2024, renewable sources accounted for approximately 23% of the country's electricity generation, while thermal power plants maintained a share of approximately 67,5% in the Japanese electricity mix.

Dependence on fossil fuels increased after the Fukushima nuclear accident in 2011, when much of Japan's nuclear power plants were shut down. Since then, the country has been gradually expanding the share of renewable sources without compromising the reliability of the system.

Solar power in a limited territory

Despite its territorial limitations, Japan ranks among the world's leading solar markets, according to data from this year's Solar Power Europe report. The country has one of the highest densities of installed photovoltaic capacity per square kilometer among major global economies.

This growth was driven by incentive policies implemented after Fukushima and the need to reduce external energy dependence. In addition to distributed generation, Japan is also investing in floating solar power plants and solutions to maximize the use of urban and industrial areas.

The future lies in perovskite.

One of Japan's main technological bets for the next decade lies in perovskite solar cells. Because they are lightweight, flexible, and potentially cheaper, these cells are seen by the Japanese government as a strategic alternative to expand solar power generation in areas where conventional modules face structural limitations.

The government has allocated 49,8 billion yen to support the development and industrialization of this technology. Recently, the country also reaffirmed its goal of increasing the share of renewable sources to between 40% and 50% of the electricity mix by 2040, focusing on energy storage and the modernization of electricity grids.

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