Wholesale design: JEPX operates a voluntary day-ahead spot auction with 48 half-hour products and blind single-price clearing, plus continuous intraday trading and forward products.
Operator
Japan Electric Power Exchange (JEPX) for wholesale trading; EPRX and the transmission system operators for balancing; OCCTO for capacity-market administration
Where energy trades
Where does energy trade in Japan wholesale and balancing markets?
Energy in Japan wholesale and balancing markets trades in 3 layers: day-ahead spot, intraday and forward.
What a battery can sell
What ancillary services can a battery sell in Japan wholesale and balancing markets?
Japan wholesale and balancing markets has 5 ancillary-service products, across 3 families — frequency containment, automatic frequency restoration and manual frequency restoration: Primary Control Reserve / Frequency Containment Reserve, Secondary Control Reserve 2 / Frequency Restoration Reserve, Tertiary Control Reserve 1 / Replacement Reserve, Tertiary Control Reserve 2 / Replacement Reserve for FIT, Secondary Control Reserve 1 / Synchronized Frequency Restoration Reserve. Response timing, direction and eligibility for each are in the cards below, as the official sources state them.
Facts below are stated as the official sources state them. A missing line means the
source does not state that value — never that the value is zero.
Frequency containment
Primary Control Reserve / Frequency Containment Reserve 一次調整力 / FCR
operational
Address extremely short-cycle imbalance and generation-loss contingencies through local frequency control.
Direction
raise; lower
Full activation
10 s
Sustain
at least 5 min
Trigger / range
Automatic local control outside a deadband no wider than plus/minus 0.01 Hz in 50 Hz areas or plus/minus 0.012 Hz in 60 Hz areas. For contingency-quantity assessment, the abnormal-event criterion is a sustained 0.2 Hz fall from nominal, or 0.3 Hz in Hokkaido.
Eligibility
Prequalified generators, storage, demand resources and aggregations meeting local-control, telemetry and response tests.
Typical procurement
Area procurement requirements vary by week/day and are not reduced to one national typical range.
Automatic frequency restoration
Secondary Control Reserve 2 / Frequency Restoration Reserve 二次調整力② / FRR
operational
Correct longer-period forecast error arising after gate closure.
Direction
raise; lower
Full activation
5 min
Sustain
at least 30 min
Trigger / range
TSO economic-dispatch-control signal; not a frequency-relay product.
Eligibility
Prequalified generation, storage, demand resources and aggregations with qualifying control/telemetry.
Typical procurement
Area- and interval-specific requirements.
Secondary Control Reserve 1 / Synchronized Frequency Restoration Reserve 二次調整力① / S-FRR
operational
Correct short-cycle within-period variation and respond to generation loss through load-frequency-control signals.
Direction
raise; lower
Full activation
5 min
Sustain
at least 30 min
Trigger / range
TSO load-frequency-control signal; no one national Hz trigger.
Eligibility
Prequalified resources able to receive LFC signals and meet monitoring/performance tests.
Typical procurement
Area- and interval-specific requirements.
Manual frequency restoration
Tertiary Control Reserve 1 / Replacement Reserve 三次調整力① / RR
operational
Cover demand and renewable forecast error after gate closure and generation outages.
Direction
raise; lower
Full activation
15 min
Sustain
at least 30 min
Trigger / range
TSO dispatch instruction; no fixed Hz trigger.
Eligibility
Prequalified online or start-capable generation, storage, demand resources and aggregations.
Typical procurement
Area- and interval-specific requirements.
Current EPRX product overview (updated 13 March 2026) states 15-minute response and 30-minute sustain. The FY2025 OCCTO comparative table used a three-hour continuation/trading block; retain that distinction for historical 2025 analysis.
Tertiary Control Reserve 2 / Replacement Reserve for FIT 三次調整力② / RR-FIT
operational
Cover renewable-generation forecast errors associated with the FIT special scheme.
Direction
raise; lower
Full activation
1 h
Sustain
at least 30 min
Trigger / range
TSO dispatch instruction based on renewable forecast error.
Eligibility
Prequalified generation, storage, demand resources and aggregations able to follow the product schedule.
Typical procurement
Area- and interval-specific renewable forecast-error requirement.
Getting paid to exist
Does Japan wholesale and balancing markets have a capacity mechanism?
Yes — OCCTO Capacity Market is a central capacity market.
OCCTO Capacity Market
operational
The main auction procures capacity four years ahead, with area-price formation and capacity-obligation contracts. Additional auctions address later shortfalls. A separate long-term decarbonised-capacity auction provides multi-year investment support.
Auction held in 2025
Yes
()
— The source gives the auction year without a day, so only the year is shown.
Calendar-2025 bidding included the FY2025 main auction for delivery FY2029, an additional auction for FY2026 delivery and the long-term decarbonised auction whose bid window fell in January 2025.
Caveats
Technical notes
EPRX's balancing market has five product families; all five had entered market trading by April 2024. Procurement and activation remain area/TSO coordinated.
Current as of · from the
Global Electricity Market Catalogue v1.2.0 (compiled to , CC BY 4.0). Facts belong to the linked official authorities;
verify the current rules before design or bidding decisions.
Questions
Common questions about Japan wholesale and balancing markets
Who operates Japan wholesale and balancing markets?
Japan wholesale and balancing markets covers Japan and is operated by Japan Electric Power Exchange (JEPX) for wholesale trading; EPRX and the transmission system operators for balancing; OCCTO for capacity-market administration.
Was a qualifying capacity event held in Japan wholesale and balancing markets in 2025?
Yes. OCCTO Capacity Market: a qualifying 2025 event is recorded (2025). The source gives the auction year without a day, so only the year is shown.
How is energy traded, priced and settled in Japan wholesale and balancing markets?
Japan wholesale and balancing markets: JEPX operates a voluntary day-ahead spot auction with 48 half-hour products and blind single-price clearing, plus continuous intraday trading and forward products.