The Tokyo Metropolitan Government, aiming to achieve its "carbon halving" goal of reducing the city's greenhouse gas emissions by 50% by 2030, is promoting the use of renewable energy. Starting in April 2025, a new system mandating the installation of solar power will be implemented. This means that houses that begin construction this year will need to prepare for installation.
This system applies to new residences "provided by major house builders with a total area of less than 2000 square meters," requiring the installation of at least 2 kW of photovoltaic panels. It does not apply to existing houses. Some buildings with roof conditions such as "small area" or "north-facing" are exempt from the installation requirement.
Major house builders are defined as those supplying a total area of 20,000 square meters or more in Tokyo each year. The Tokyo Metropolitan Government expects about 50 major residential manufacturers to qualify. However, small and medium-sized construction companies are not subject to this obligation. It is estimated that only half of the new buildings in Tokyo (40,000 to 50,000 units per year) will be subject to this obligation.
Other cities in Japan are also starting to mandate the installation of solar power equipment. Kyoto Prefecture has required the installation of photovoltaic power generation and other renewable energy equipment since April 2022 for new or expanded buildings with a total floor area between 300 and 2000 square meters. Considering the cost burden on homebuyers, Kyoto Prefecture has implemented a subsidy plan and support programs such as the "Kyoto Zero Yen Solar Platform" system, which allows the installation of photovoltaic power generation equipment at zero initial cost.
In March last year, the Tokyo Metropolitan Government established a 150 billion yen fund to subsidize the installation of solar power generation equipment for Tokyo residents. Subsidies will be provided if solar panels are installed during the construction of new eco-friendly houses or while retrofitting existing houses with insulation.
Cost Recovery in 6 Years
For example, with a 4 kW photovoltaic system costing 980,000 yen, the municipal government will provide a subsidy of 400,000 yen, leaving a self-payment cost of only 580,000 yen. The standard electricity price set by the National Fair Trade Commission for household appliances is 31 yen per kilowatt-hour. If you generate 5,000 kilowatts of solar power annually, with about 30% (1,500 kilowatts) used for your own consumption, you can save 46,500 yen on electricity bills annually. Combined with the income from selling electricity, you can save about 100,000 yen per year. By reducing electricity bills and earning income from selling electricity, the cost can be recovered in about 6 years. Comparing the expenses and income over 30 years, you can benefit up to 1.59 million yen.
Japan's Photovoltaic Sales Income
Currently, Japan's feed-in tariff (FIT) guarantees the purchase price of electricity generated by household photovoltaic systems for 10 years. The power generation capacity of household photovoltaic systems is generally below 10 kilowatts. The Agency for Natural Resources and Energy has announced that the FIT for the 2024 fiscal year is 16 yen per kilowatt-hour. According to the Photovoltaic Power Generation Association, the annual power generation of photovoltaic systems is about 1,000 kilowatt-hours per kilowatt. Under the FIT system, the purchase price after installation is guaranteed for 10 years. It should be noted that the purchase price after 10 years will be determined by individual contracts with power companies.
Developers Responding to Policies
Recently, Mitsui Fudosan Residential and TEPCO Energy Partner announced the introduction of the fixed-rate solar power service Enekari Plus in the apartments of Park Homes Yoyogi Nishihara (scheduled for completion in May 2025) and Park Homes Kami-Itabashi (scheduled for completion in June 2025). This is the first time Enekari Plus is being used in newly sold apartments in Tokyo. A feature of Enekari Plus is that service users can install solar power generation equipment at zero initial cost and pay a fixed fee monthly. After the 15-year contract period ends, the solar power generation equipment will be transferred to the service users for free.
Source：focus_solar
