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EDITORIAL | Tokyo Governor Should Rethink Solar Panels Plan

Before rushing through a mandate for solar panels in new homes, Tokyo must deal with the costs, damage, recycling, human rights, and other issues it creates.



Tokyo Governor Yuriko Koike ( Source: Tokyo Metropolitan Government)

Mandatory installation of solar power in newly built homes, including detached houses? 

This is Tokyo Governor Yuriko Koike’s new signature plan, and revisions to the ordinance for introduction of the system are already being proposed. Meanwhile, questions concerning who bears the costs of installation and recycling, among others, are entirely unresolved. Isn’t this being handled too impetuously? 

Reducing Greenhouse Gasses

Tokyo aims to halve greenhouse gas emissions by 2030, relative to levels in the year 2000. The plan was then referred to the Tokyo Metropolitan Environment Council with the statement that  30% of carbon dioxide emissions were generated from households.  

Houses with solar panels in Matsudo City, Chiba Prefecture, near Tokyo.

An interim report on the amendment compiled by the Tokyo government says the mandate will be applied to housing manufacturers that annually supply 20,000 square meters or more of floor area. The manufacturers will be required to install solar panels on homes with a total gross floor area of less than 2,000 square meters. 

Under the new rule, around 50 housing manufacturers operating in the Tokyo area will fall under the mandate, with close to half of the 40,000 to 50,000 new construction starts targeted annually.

Costs Not Thought Through

The cost for installing solar panels is roughly ¥1 million JPY ($7,330 USD). Adding the cost on top of housing prices, it only increases the burden on home buyers. The lifespan of a solar panel is said to range from 20 to 30 years, but the recycling process for old panels is far from perfect. A vast amount of used panels may well be simply abandoned.

How about safety issues during natural disasters? For example, Shibata City in Niigata Prefecture has issued a warning that in the case of typhoons and earthquakes, solar panels could be damaged, but they can still generate electricity when light hits them, which could cause electric shock. Many other local municipalities are also issuing similar warnings. 


When power distribution becomes excessive, a massive blackout could occur due to an imbalance in supply and demand. There’s also a limit to how far the output of household power can be controlled. 

To begin with, the Ministry of Land, Infrastructure, Transport and Tourism previously considered mandating the installation of solar panels, but decided to pass on the plan. The main reason for the decision was a disparity in power generation efficiency among the different regions and areas. Under the circumstances, uniform application of a plan was impossible. 

Barbed wire around reeducation camp aimed at Uyghurs in Xinjiang region, China

Supply Chain and Human Rights

On top of that, 80% of the polycrystalline silicon needed to make solar power panels is made in China, and more than half is produced in the Xinjiang Uygur Autonomous Region. A thorough explanation is required on the human rights issue. 

The use of domestically produced solar panels is also an important issue.

Although Tokyo says the up-front expenses for solar panels installed on standard detached houses can be recovered in 10 years, the financial burden of damage is still unclear. 

Thinking It Through

Tokyo aims to set up the ordinance amendment within 2022. If systematized, it will be the first of its kind in the country. 

Governor Koike told the Metropolitan Assembly, “We will continue to consider a flexibility component where individuals can choose whether or not to install the equipment.” But, first, how about taking the concept of a compulsory solar panel plan back to the drawing board?   


(Read the editorial in Japanese at this link.)

Author: Editorial Board, The Sankei Shimbun