Mandatory installation should be paired with measures to reduce burden

To cut greenhouse gas emissions, measures targeting households are important. It is hoped that an effective system will be put in place to expand the installation of solar panels at homes without imposing a one-sided burden on household budgets.

The Tokyo metropolitan government has announced plans to require the installation of solar panels at a certain percentage of newly constructed homes and residential buildings sold in the capital. It said it aims to start implementing the plans in April 2025. If realized, the mandate will be the first of its kind in Japan.

The metropolitan government has set a 2030 goal of cutting greenhouse gas emissions by half from the level in 2000, but as of fiscal 2020, emissions have been only slightly reduced.

Industry, transportation and other sectors have achieved some declines, but because of an increase in households, this sector was the only one that increased emissions, by over 30% from fiscal 2000. If this situation continues, the metropolitan government will have difficulty achieving its target.

One effective measure is installing solar panels at homes. The metropolitan government’s plan to promote the spread of solar panels is reasonable.

However, in a public opinion poll conducted by the metropolitan government, 56% of respondents were in favor of making the installation mandatory, while 41% were opposed. Careful design of the system is desirable.

According to the metropolitan government, the mandate will not be applied to buyers of homes but to the entities that build them. Specifically, the about 50 companies with the most construction and sales of residences over a certain square meter in Tokyo will be subject to the rule, with the percentage of homes that must have solar panels set depending on the locality.

As examples of taking circumstances into consideration, the wards of Chiyoda and Chuo with many high-rises and poor sunlight will be at 30%, while wards and cities with mainly low-rise residences will be at 85%. As a result, the metropolitan government expects solar panels to be installed in about half of all newly built homes.

It is necessary to fully inform Tokyo residents about this system.

In addition, it is essential to implement the system together with measures to support home buyers.

The initial cost of installing solar panels is about ¥1 million. Housing prices are rising amid soaring costs of materials and timber. If the cost of solar panels is added, many people may give up purchasing homes.

The metropolitan government envisages that if solar panels are installed at ordinary households, solar power generated could cover about 80% of their annual electricity consumption, with the initial cost recouped in about 10 years through savings on electricity bills and revenue from selling solar power. However, some people have pointed to the disparity in electricity generation from place to place, so the cost may not be recovered as intended in some locations.

The metropolitan government has said it will consider support measures. The expansion of subsidies and leasing of solar panels without the initial cost should be promoted.

Besides Tokyo, the Kawasaki city government also aims to make the installation of solar panels mandatory, with many other local governments appearing to be interested. Should more local governments follow suit, it is desirable that the central government will look into measures to alleviate the burden on home buyers.

(From The Yomiuri Shimbun, Sept. 18, 2022)