JEPX 30-day volatility: system price mean ¥20.82/kWh, standard deviation ¥8.74, coefficient of variation 42%, P10–P90 ¥9.33/kWh to ¥29.90/kWh, spike hours 6 h; widest mean area spread Tokyo−Shikoku +14.90 ¥/kWh.
- 30d mean
- ¥20.82/kWh
- Std dev
- ¥8.74
- CV
- 42%
- P10 / P90
- ¥9.33 / ¥29.90
- Spike hours
- 6 h
- Widest spread
- Tokyo−Shikoku +14.90
Risk analytics · 30 days · 1,536 slots
Volatility & Spreads
Area statistics
Slot-level distribution, intraday shape and congestion (price split vs system)
| Area | Mean | Std | CV % | P10 | P90 | Max | Daily σ | Within-day σ (day-ahead) | Peak/Off | Floor h | Spike h | Split % |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ■ System (システム) | 20.82 | 8.74 | 42 | 9.33 | 29.90 | 47.88 | 4.72 | 7.22 | 0.96 | 17.0 | 6.0 | 0 |
| ■ Hokkaido (北海道) | 18.26 | 12.84 | 70 | 5.00 | 32.22 | 105.00 | 6.63 | 10.19 | 0.92 | 38.5 | 49.0 | 97 |
| ■ Tohoku (東北) | 21.93 | 11.21 | 51 | 3.00 | 34.31 | 50.01 | 5.11 | 9.79 | 0.86 | 44.0 | 13.5 | 96 |
| ■ Tokyo (東京) | 25.83 | 7.71 | 30 | 19.41 | 35.16 | 50.01 | 4.23 | 6.14 | 1.04 | 8.0 | 0.0 | 98 |
| ■ Chubu (中部) | 24.71 | 8.42 | 34 | 12.41 | 34.59 | 46.45 | 4.82 | 6.62 | 1.01 | 12.0 | 0.0 | 97 |
| ■ Hokuriku (北陸) | 17.83 | 8.73 | 49 | 9.39 | 30.00 | 46.45 | 5.79 | 6.33 | 1.27 | 12.0 | 42.0 | 96 |
| ■ Kansai (関西) | 17.57 | 8.78 | 50 | 8.61 | 30.00 | 46.45 | 5.93 | 6.30 | 1.28 | 15.0 | 43.5 | 96 |
| ■ Chugoku (中国) | 14.61 | 7.85 | 54 | 3.11 | 23.61 | 44.79 | 4.21 | 6.51 | 1.01 | 40.5 | 33.5 | 97 |
| ■ Shikoku (四国) | 10.92 | 6.93 | 63 | 0.02 | 20.05 | 37.51 | 3.72 | 5.58 | 0.95 | 76.0 | 42.5 | 97 |
| ■ Kyushu (九州) | 14.14 | 7.68 | 54 | 2.90 | 22.43 | 44.79 | 3.59 | 6.62 | 0.96 | 46.0 | 31.5 | 97 |
Rolling 7-day intraday volatility
Mean within-day standard deviation of slot prices (¥/kWh)
- Hokkaido (北海道)
- Kansai (関西)
- Kyushu (九州)
- System (システム)
- Tokyo (東京)
Price distribution
Share of slots per price band (%)
- Hokkaido (北海道)
- Kyushu (九州)
- Tokyo (東京)
Daily spread vs Tokyo (東京)
Area daily average minus Tokyo daily average · negative = cheaper than Tokyo
- Chubu (中部)
- Chugoku (中国)
- Hokkaido (北海道)
- Hokuriku (北陸)
- Kansai (関西)
- Kyushu (九州)
- Shikoku (四国)
- Tohoku (東北)
Inter-area spread & coupling matrix
Mean spread row − column (¥/kWh) — positive = row area more expensive
| row − col | HKD 北海道 | THK 東北 | TKO 東京 | CBU 中部 | HRK 北陸 | KNS 関西 | CGK 中国 | SKK 四国 | KYS 九州 |
|---|---|---|---|---|---|---|---|---|---|
| Hokkaido 北海道 | · | -3.67 | -7.56 | -6.44 | +0.43 | +0.70 | +3.65 | +7.34 | +4.12 |
| Tohoku 東北 | +3.67 | · | -3.89 | -2.77 | +4.10 | +4.37 | +7.32 | +11.01 | +7.80 |
| Tokyo 東京 | +7.56 | +3.89 | · | +1.12 | +8.00 | +8.26 | +11.22 | +14.90 | +11.69 |
| Chubu 中部 | +6.44 | +2.77 | -1.12 | · | +6.88 | +7.14 | +10.10 | +13.78 | +10.57 |
| Hokuriku 北陸 | -0.43 | -4.10 | -8.00 | -6.88 | · | +0.26 | +3.22 | +6.91 | +3.69 |
| Kansai 関西 | -0.70 | -4.37 | -8.26 | -7.14 | -0.26 | · | +2.96 | +6.64 | +3.43 |
| Chugoku 中国 | -3.65 | -7.32 | -11.22 | -10.10 | -3.22 | -2.96 | · | +3.69 | +0.47 |
| Shikoku 四国 | -7.34 | -11.01 | -14.90 | -13.78 | -6.91 | -6.64 | -3.69 | · | -3.22 |
| Kyushu 九州 | -4.12 | -7.80 | -11.69 | -10.57 | -3.69 | -3.43 | -0.47 | +3.22 | · |
Market coupling · 30dAll 9 areas one price: 0.8% of half-hoursWestern block (Chubu→Kyushu) one price: 4.6%
HKD–THK 54% split -3.67THK–TKO 30% split -3.89TKO–CBU 35% split +1.12CBU–KNS 75% split +7.14CBU–HRK 72% split +6.88HRK–KNS 6% split +0.26KNS–CGK 33% split +2.96KNS–SKK 59% split +6.64CGK–SKK 41% split +3.69CGK–KYS 6% split +0.47
Adjacent interconnector pairs · split = area prices differ by more than ¥0.005 · mean spread = first − second area (¥/kWh)
Interconnector congestion (連系線混雑)
OCCTO tie-line flows vs usable capacity · 2026-09-23 → 2026-10-22 · 35% of adjacent-area splits coincide with a congested link · 43.8 congested link-hours/day
HKD→THK32%
util 72%splits 36% congested
THK→TKO30%
util 80%splits 73% congested
TKO→CBU34%
util 72%splits 45% congested
CBU fence import35%
util 85%splits 44% congested
HRK fence import0%
util 16%splits 0% congested
KNS fence import3%
util 70%splits 4% congested
KNS←CGK19%
util 78%splits 42% congested
KNS←SKKbase
util 100%
CGK←SKK23%
util 81%splits 40% congested
CGK←KYS6%
util 52%splits 41% congested