TOKYO, Mar 30 (News On Japan) - Long-running tensions surrounding Iran are expected to push up household electricity bills, with Japanese power companies bracing for higher costs this summer as crude oil prices remain elevated, even as Japan has shifted its energy mix toward renewables, now accounting for more than 20% of total power generation following the Great East Japan Earthquake.
Among these, solar power has taken the largest share, supported by government incentives that have driven steady growth in both large-scale solar farms and rooftop installations on homes and offices, although environmental concerns, landscape issues, and regulatory violations involving some mega-solar projects have prompted calls under the Takaiichi administration to reassess Japan’s solar energy policies.
In a residential area of Tokyo, workers were seen installing solar panels on rooftops, each weighing around 20 kilograms, with lighter designs improving ease of installation, while battery storage systems were also added to store generated electricity.
One homeowner, Kirihara Tomomi, decided to install solar panels ahead of the March deadline for Tokyo’s subsidy program, which triggered a surge in last-minute demand, noting that subsidies significantly reduced the total cost of 3.77 million yen, with approximately 2.34 million yen covered by the Tokyo metropolitan government.
The system began operating the following day, generating around 3.3 kilowatts under sunlight, with a maximum output of 4.6 kilowatts from 10 panels depending on weather conditions, while excess energy can be stored in a battery with a capacity of up to 15 kilowatts, enough to cover roughly one day of electricity use for a typical four-person household in the event of a blackout.
Despite growing adoption, the installation rate of solar systems across buildings in Tokyo remains at about 6%, partly due to the weight of conventional panels, which many roofs and factories cannot support, as well as seismic safety concerns, while most panels currently in use are manufactured overseas, with China accounting for roughly 80% of supply.
Against this backdrop, the government is promoting perovskite solar cells, a next-generation technology developed in Japan that uses thin, flexible film weighing about one-tenth of conventional silicon panels and capable of being installed on a wide range of surfaces.
Seen as a potential breakthrough amid rising energy costs driven by geopolitical tensions, domestically produced solar technology could offer Japan a path toward greater energy independence.
At the forefront of this effort is Sekisui Chemical, where researchers are working to commercialize flexible perovskite solar cells, with rooftop test installations demonstrating various configurations designed to maximize solar energy capture.
Morita, a veteran with 34 years at the company, has led the development, which began 13 years ago with a small team of three, initially facing skepticism before gaining momentum as a company-wide strategic project targeting commercialization by fiscal 2025.
Sekisui Chemical, with annual sales of around 1.3 trillion yen, operates across housing materials, high-performance plastics, and protective films used in automotive glass, leveraging its materials expertise to advance the new solar technology.
Perovskite solar cells consist of multiple layered materials, with a key component being a crystalline structure known as perovskite, which converts light into electricity within an ultra-thin film of just one micron, using iodine as a primary raw material.
That iodine, sourced from ancient underground brine deposits, represents a domestic resource that researchers believe could underpin Japan’s competitive advantage in next-generation solar energy, offering hope that the country can reclaim a leading position in the global solar market while addressing rising electricity costs.
Source: テレ東BIZ
