Japan’s Ministry of the Environment and Ministry of Economy, Trade and Industry (METI) have proposed a 50-metric-ton threshold for advance disposal plans under the country’s forthcoming solar panel recycling law. The proposal was presented to a study group responsible for drafting the law’s implementing rules.
The Act on Promoting the Recycling of Solar Cell Waste was enacted on May 29 and promulgated on June 5. It must take effect within 18 months, with the government targeting early December 2027. The ministries plan to publish the detailed rules around spring 2027, after a joint council reviews the proposals and public consultation takes place.
The law would establish three levels of responsibility. All panel disposers would have a general duty to promote recycling. Commercial operators, including rooftop owners that sell electricity, would be subject to government guidance. Operators exceeding the eventual threshold would need to submit disposal plans in advance and could face recommendations or orders.
The ministries compared thresholds of 40, 50 and 60 metric tons. The proposed 50-metric-ton threshold would cover 7,398 facilities and capture an estimated 38.3% of panel waste expected between 2027 and 2050. A 40-metric-ton limit would cover 8,368 facilities and 38.7% of waste, while a 60-metric-ton limit would cover 6,784 facilities and 37.9%.
The ministries said the 50-metric-ton option would avoid placing excessive requirements on smaller facilities while still covering most plants with capacity of at least 1 megawatt. Based on 6,267 module models installed in Japan, 94.9% correspond to at least 50 metric tons per megawatt of capacity. Industry outlet IRU-MIRU reported that most study group members supported this threshold, although some favored 40 metric tons to broaden coverage.
The proposed rules would also address attempts to avoid the threshold by dividing a project’s disposal into smaller batches. Panels removed from the same plant during a decommissioning or repowering project within a defined period—around one year as a guide—would be counted as a single disposal. Documented replacements following disasters, equipment failures or routine maintenance would not be treated as split disposals.
The law would apply only to panels weighing at least 3.7 kilograms each. This limit is intended to exclude small products such as calculator cells while covering almost all conventional modules. Silicon panels, which the ministries say represent about 95% of global production, would be included alongside CIGS and CdTe thin-film technologies. Single-glass, double-glass and building-integrated photovoltaic panels would also fall within the proposed scope.
Double-glass modules accounted for 39.3% of shipments by 17 members of the Japan Photovoltaic Energy Association in 2025. Among 81 waste processors surveyed, 46 said they could accept double-glass panels and 21 said they could process building-integrated photovoltaic panels.
Organic cells, including glass and film perovskite modules, would initially be excluded, as would gallium arsenide, other specialty compound cells and glass-fiber flexible panels. The ministries said suitable recycling technologies and processing routes are not yet available for these products, adding that the scope could be reconsidered as technology and markets develop.
The new requirements would supplement existing decommissioning provisions. Since July 2022, projects of at least 10 kilowatts covered by Japan’s feed-in tariff and feed-in premium schemes have been required to reserve funds for decommissioning.
The government expects end-of-life solar panel waste to reach as much as approximately 500,000 metric tons annually in the 2040s, exceeding an earlier estimate of 170,000 to 280,000 metric tons per year around 2035 to 2037. The proposed exclusions for perovskite modules come as Japan seeks to deploy 20 gigawatts of the technology by 2040.
Sources: pv magazine.