Solar Power in Japan

William Genesen
January 3, 2017

Submitted as coursework for PH240, Stanford University, Fall 2016


Fig. 1: Solar panels of the Aeon Mall in Itami-Koya, Hyogo Prefecture, Japan. (Source: Wikimedia Commons)

Solar energy is one of the most efficient and useful renewable energy sources available right now. Due to the mass movement of moving away from non-renewable energy to renewable energy around the world, solar power energy has been a top solution as it is cost effective compared to other options and creates an impressive amount of energy by harnessing the sun. Many countries around the world have been implementing solar power wherever possible, but it requires clear skies, relatively flat surfaces, and an abundance of sunlight. Countries such as Germany have been taking the lead in the production and use of solar power. However, over the past couple of years Japan has been slowly implementing this effective new power source. Because of the nuclear meltdown a few years ago, Japan's main energy source of nuclear power plants have been shut down since the event. Due to a need for a renewable energy source, they have been trying to take advantage of solar power.

What is Solar Power

Solar power is collected by solar panels. Each solar panel is comprised of smaller units called photovoltaic cells. Each photovoltaic cell is made of two slices of a semi conducting material (commonly silicon). [1] Each photovoltaic cell works by using particles of light to knock electrons free from atoms, which generates a flow of electricity.

Japan's Use of Solar Power

Over the last couple of years Japan has begun to try to take advantage of solar power. (See Fig. 1.) The biggest problem with solar power that the country is facing has to do with its geography. Japan is on a small island, and due to its considerably large population, space is at a premium. The few unpopulated parts of the country are too hilly for practical use of Solar Power. Scientist have come up with an innovative alternate solution. Solar power farms are being built offshore on reclaimed land. In 2014, Japan turned on its largest solar panel plant to date. The power plant was built by Kyocera Corporation. Kagoshima Nanatsujima Mega Solar Power plant creates enough energy to power 22,000 homes. While this form of renewable energy is not powerful enough to power the whole country, it is a step in the right direction. The next plan Japan has is to create the ultimate offshore power plant. [2] The idea is to have solar panels wrap around the moon's equator and then the energy would transmit to the earth through microwave power transmission (MPT). This would bring a remarkable 13,000 terawatts of electricity per year. This clean and practically limitless energy resource from space could be a huge step for not only Japan, but mankind.


Although Japan is not known as a leader in the solar power industry, they are certainly looking into every possible use of it. [3] In doing so, they have been a leader in the concept of putting solar panels in space and transmitting it to earth through MPT. This would lead to a limitless energy source in space that would take up no room on earth and weather would not play a factor. But for now, Japan is continuing to add solar panel plants around the country. Japan has clearly made a shift to focusing on renewable energy sources for the future, likely involving some amount solar power energy.

© William Genesen. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] K. P. M. Bogus, "Photocell, its Method of Manufacture, and a Solar Panel Comprising Such Cells," U.S. Patent 5,542,988, August 1996.

[2] H. Matsumoto, "Research on Solar Power Satellites and Microwave Power Transmission in Japan," IEEE Microwave Magazine 3, 36 (2003).

[3] N. Shinohara and S. Kawasaki, "Recent Wireless Power Transmission Technologies in Japan for Space Solar Power Station/Satellite," IEEE 4957272, 18 Jan 09.