How to dynamically determine EPRX bidding strategy for each 30-minute block? This article provides a 5-product SoC dynamic decision framework, day-ahead JEPX forecast integration, and a ¥191M annual revenue case study for a 10 MW BESS.
EPRX × BESS Series (Article 40–44)
Building on EPRX rule mastery (Article 40), this article explores how to dynamically determine the optimal bidding strategy for each 30-minute block. The core of the Offer Stack is to simultaneously maximize EPRX clearing probability and JEPX arbitrage opportunities under SoC constraints.
| Product | Min SoC Requirement | Priority | Decision Condition |
|---|---|---|---|
| Primary Reserve (GF) | SoC 30–70% | Highest | Price cap ¥15.00, bid first |
| Secondary Reserve-1 (LFC) | SoC 25–75% | High | Combined bid with GF (same capacity) |
| Secondary Reserve-2 (EDC Fast) | SoC 20–80% | Medium | Price cap ¥7.21, bid with remaining capacity |
| JEPX Arbitrage | SoC 0–100% | Low | Use remaining capacity when EPRX not cleared |
| Revenue Source | Annual Revenue (¥M) | Assumptions |
|---|---|---|
| Primary Reserve (GF) | ¥75M | 70% clearing rate, avg ¥12/ΔkW |
| Secondary Reserve-1 (LFC) | ¥68M | 65% clearing rate, avg ¥11/ΔkW |
| Secondary Reserve-2 (EDC Fast) | ¥18M | 60% clearing rate, avg ¥5.5/ΔkW |
| JEPX Arbitrage | ¥30M | 150 arbitrage opportunities/year |
| Total | ¥191M | — |
With EPRX fully transitioning to day-ahead trading, the core logic of Offer Stack strategy has fundamentally changed:
EPRX × BESS Series (Article 40–44)
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Enter BESS specs and EPRX/JEPX parameters to generate optimal Offer Stack allocation
BESS Specifications
EPRX Bidding Parameters
JEPX Arbitrage Parameters
SoC Capacity Allocation
Revenue Breakdown
Priority
Strategy Note
After the shift to day-ahead markets, EPRX bidding and JEPX arbitrage decisions are made simultaneously before 12:00 daily, enabling co-optimization of both markets within the same decision window.
※ This calculator uses a priority-based greedy strategy: EPRX GF → LFC → EDC → JEPX arbitrage, with SoC buffer as the final defense line
※ JEPX arbitrage is executed only during peak hours (18:00–22:00) when forecast price spread > ¥5/kWh
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EPRX × BESS Series (Article 40–44)
Series Progress
Article 2 of 5
BESS Optimal Offer Stack Construction
This ArticleThis series provides an in-depth analysis of the complete BESS revenue pathway in Japan's electricity market, from EPRX rules to financial modeling.
Rules Foundation
Bidding Strategy
Capacity Market
Risk Management
Financial Model
免責聲明 / Disclaimer： Blog articles are for educational and reference purposes only and do not constitute investment advice.
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