Japan FIT Solar Curtailment 2026: FIT vs FIP Guide

What the New Curtailment Order Changed

Before FY2026, Japan's curtailment dispatch order treated FIT and FIP generators roughly proportionally: when grid congestion required reducing renewable generation, the obligation was shared across both types based on their relative volumes and location. No single generator type was disproportionately exposed to curtailment loss.

From October 1 2025, that changed. The new order explicitly places FIT projects at the front of the curtailment queue. When a grid operator needs to reduce renewable generation to manage grid balance, FIT projects are curtailed first and most. FIP projects are curtailed only after FIT capacity has been fully curtailed. The logic: FIP projects have market exposure and financial structures that reflect curtailment risk, whereas FIT projects receive a fixed government-backed rate and were historically assumed to be protected. The new order removes that assumption.

The income consequence is stark. For a FIT project, curtailed generation earns nothing. There is no compensation, no make-whole payment, and no mechanism to recover the lost FIT income. Shulman Advisory's analysis explicitly states this: generators on FIT who are curtailed receive zero income for the curtailed period. For FIP projects, the JPY 1 per kWh increase in the balancing cost subsidy for FY2025, confirmed by METI ANRE, partially offsets the cost of managing market exposure during curtailment periods.

Why Kyushu, Shikoku, and Hokkaido Face the Highest Risk

Curtailment frequency is not uniform across Japan's grid. Three regions face structurally elevated curtailment risk due to combinations of high renewable penetration and limited grid flexibility.

Kyushu is the most exposed. The region has a high concentration of solar installations, including a significant portion of Japan's existing utility-scale solar capacity. Two factors compound this: the restart of nuclear reactors at Sendai and Genkai, adding large blocks of inflexible baseload generation to a grid with too much non-dispatchable supply during sunny periods; and limited interconnection capacity to the Honshu grid that could otherwise absorb excess Kyushu generation. Under the new curtailment order, FIT projects in Kyushu bear the full brunt of these grid balance events.

Shikoku has similar structural characteristics: high solar penetration relative to local demand and limited interconnection with the broader Honshu grid. Hokkaido faces curtailment risk from a different direction. Its renewable portfolio is heavily weighted toward wind, and the HVDC Hokkaido-Honshu interconnection link has limited capacity relative to the island's renewable generation potential.

Identifying Which of Your Clients Are Affected

Not all FIT projects face the same curtailment exposure. The clients most at risk are those with ground-mount FIT projects in Kyushu, Shikoku, or Hokkaido generating income that forms a material part of a project's debt service or investor return.

The diagnostic process: review the monitoring data for FIT projects in these regions. Compare actual generation in the October 2025 to April 2026 period against expected generation based on irradiance data for the same period. A consistent shortfall of 5 to 20 percent during periods of otherwise normal irradiance, particularly on clear winter days when solar output should be at a predictable level, is an indicator of curtailment events under the new order.

Clients who do not yet know their project is being curtailed at a higher rate than before October 2025 will find out when they receive electricity account statements showing lower FIT income than expected. Being the EPC who proactively identified the issue and brought a solution in the form of FIT to FIP conversion is the professional posture that converts this challenge into a deepened client relationship.

FIT to FIP Conversion: What It Involves

Converting an existing FIT project to FIP status is a formal process requiring application to either OCCTO or the METI certification system, depending on project size and jurisdiction. The conversion is not a simple administrative change. It involves transitioning the project from a fixed government-backed FIT tariff to the market-price-referenced FIP mechanism, which requires arrangements for electricity trading and market exposure management.

The practical steps: retain an energy aggregator who will manage the project's electricity sales in the market; complete the application to the relevant authority; obtain confirmation of the new FIP designation; and adjust the project's financial model to reflect FIP revenue structure. For projects on debt financing, the change to FIP revenue structure may require lender consent if the loan documentation specifies FIT income as the basis for debt service. Under the new curtailment order, converted FIP projects are protected from the first-in-curtailment exposure that FIT projects now face.

What the Curtailment Order Means for Future Project Decisions

The new curtailment order is another component of Japan's systematic policy shift away from FIT as the support mechanism for solar. Taken together with the FIP auction end date, the Mega Solar Countermeasure Package, and the Forest Act amendments, the direction is clear: Japan's solar market is being restructured around market-price-referenced support and distributed rooftop rather than utility-scale FIT-backed ground-mount.

For new project decisions, the curtailment order is an additional reason to favour FIP over FIT where the choice exists, and to favour rooftop FIT over ground-mount FIT in locations with elevated curtailment risk. Rooftop FIT projects in major demand centres with high self-consumption ratios are less exposed to curtailment than ground-mount FIT projects in grid-saturated rural areas. The grid dynamics driving curtailment in Kyushu and Hokkaido are driven by utility-scale generation in areas with limited local demand, not by rooftop solar on commercial buildings in population centres.

Frequently Asked Questions

Q1. Why are FIT projects curtailed before FIP projects under the new order?

The policy logic is that FIP projects are exposed to electricity market prices and have financial structures that already account for the risk of curtailment through market mechanisms. FIT projects receive a fixed government-backed tariff that was historically assumed to be protected from curtailment loss. The new order reverses that assumption: since FIP generators have market-based revenue structures that can absorb curtailment financially, while FIT generators have fixed revenue assumptions that make curtailment a pure loss, the grid operator prioritises keeping FIP generators online. The JPY 1 per kWh FIP balancing cost subsidy increase for FY2025, confirmed by METI ANRE, provides additional compensation to FIP generators for managing grid balance obligations that the new curtailment order imposes on them.

Q2. Is there any compensation for FIT income lost during curtailment periods?

No. FIT income for curtailed generation is zero, and there is no compensation mechanism. This is a structural characteristic of the FIT system in Japan: it provides a fixed tariff for electricity actually delivered to the grid, but does not guarantee delivery rights when grid balance requires curtailment. The absence of compensation is precisely what makes the new curtailment order financially significant for FIT project owners. A FIT project in Kyushu that is curtailed for 200 hours per year loses 200 hours of FIT income with no recovery. This is a direct reduction in the project's annual revenue and, for leveraged projects, a potential threat to debt service coverage if curtailment frequency increases beyond levels assumed in the original financial model.

Q3. How do I start the FIT to FIP conversion process?

The conversion requires a formal application to either OCCTO or the METI certification system depending on project size and jurisdiction. The first practical step is identifying the correct application pathway for the specific project. Then: retain an energy aggregator who will manage the project's market sales under FIP (a mandatory requirement for FIP operation); prepare the application documentation including project technical specifications, current FIT certification, and the proposed aggregator arrangement; and submit to the relevant authority. For projects with debt financing, review the loan documentation before initiating conversion, as some lenders require consent for changes to the revenue structure. Allow several months for the complete conversion process including authority review and approval.

Q4. Does the new curtailment order affect rooftop FIT projects as well?

The curtailment order applies to FIT projects as a category. However, rooftop FIT projects in urban demand centres with high self-consumption ratios are significantly less exposed than ground-mount FIT projects in grid-saturated rural areas. The curtailment events that have increased in frequency are primarily driven by large-scale utility generation in areas of the grid with limited local demand and interconnection capacity, specifically Kyushu, Shikoku, and Hokkaido. Rooftop solar on a commercial building in Osaka or Tokyo that self-consumes 60 to 70 percent of its generation is largely insulated from these dynamics because most of its generation never reaches the grid. The curtailment risk profile for urban commercial rooftop FIT is materially lower than for rural ground-mount FIT.

Q5. What is an energy aggregator and why is one needed for FiP operation?

An energy aggregator is a licensed electricity market participant who manages the sale of a generator's electricity into the Japanese wholesale market on the generator's behalf. FIT generators sell to a fixed-price programme and do not need market access. FIP generators earn a market-based reference price plus a government premium, which means their electricity must be traded in the market to establish the reference price. An aggregator handles this trading, manages the imbalance settlement, and typically provides the forecasting services required to minimise imbalance penalties. Without an aggregator arrangement, a project cannot operate on FIP terms. Before initiating FIT to FIP conversion, identify and engage an aggregator who operates in the relevant grid area, as their involvement is required for the conversion application.

Q6. Can a project still be curtailed after completing FIT to FIP conversion?

Yes. FIP projects can still be curtailed when grid balance requires it. The new curtailment order means FIP projects are curtailed after FIT projects, not that they are exempt from curtailment entirely. In a severe grid event where FIT capacity has been fully curtailed and additional curtailment is still required, FIP projects will be next in the dispatch queue. However, the practical difference is significant: FIT projects now bear the full burden of normal grid balance curtailment events, while FIP projects are only curtailed in more extreme situations. For FIT project owners in Kyushu, Shikoku, and Hokkaido experiencing regular curtailment under the new order, converting to FIP removes the most frequent source of income loss even if it does not eliminate curtailment risk entirely.

Sources

• Shulman Advisory , shulman-advisory.com , Japan FIT curtailed first from FY2026, curtailment order change, FIP balancing cost subsidy
• PV Magazine , pv-magazine.com , Japan FIT and FIP policy context, March 19 2026
• White and Case , whitecase.com , Japan renewable energy regulatory update, FY2026 curtailment order and FIP transition