In the day-ahead market on JEPX (Japan Electric Power Exchange), the 24-hour spot power prices on a weekly average basis for Sep 1-5 delivery extended gains from the previous week in East Japan (50Hz) as well as in West Japan (60Hz). Persistent hot weather continues in September, raising prices further. The start of maintenance of the grid line between Tokyo and Chubu, as well as an increase in outages of thermal power plants due to regular inspections, played a part in pushing prices up. On Sep 3, 240,000 kW of power sharing was made from the Tokyo area to the Chubu area, where a tight supply/demand balance was concerned, during the time from 14:30 to 15:00. On Sep 4-5, Typhoon No. 15 (Peipah) brought stormy weather to wide areas on the Pacific coast, reducing operation of hydropower and pumped-storage power generation.

The 24-hour spot average between Tokyo and Kansai, a major market area in East and West Japan, was Yen 3.97 on Sep 1, Yen 1.69 on Sep 2, Yen 1.76 on Sep 3, Yen 0.46 on Sep 4, and Yen 0.84 on Sep 5. All the spreads were in favor of East.

The fuel market trends in the first week of September were detailed as follows.

DES Northeast Asia spot LNG prices almost edged higher from the previous week. Prices for prompt October 2025 delivery were at low-$11's per mmBtu as of Sep 4, up 5cts from the end of the previous week (Aug 29). While prices followed the natural gas markets in Europe, buying interests from the end users in the DES Northeast Asia remained dull, which weighed on prices to some degree. The Ministry of Economy, Trade and Industry (METI) announced on Sep 3 that Japan's LNG inventories for power generation stood at 2.01 mil mt as of Aug 31, down 170,000 mt from a week before. The figure was above 1.70 mil mt at the end of August last year but below the average for the past five years (2.04 mil mt).

FOB Newcastle thermal coal prices in Australia were at $ 107 for September 2025 loading as of Sep 4, down $4.5 from the previous week.

In the crude oil market, WTI crude for October 2025 stood at mid- $63's per barrel at 13:00 on Sep 5, while Brent crude for November 2025 was trading in the high-$66's. Prices went down by around $0.5 from the end of the previous week for WTI and Brent. Possible additional production by OPEC Plus, along with an increase in crude inventory in the US, worked as a bearish sentiment.

The actual highest price during the week was at Yen 50.00 in Hokkaido on Sep 5; the actual lowest price during the week was at Yen 6.01 in Hokkaido & Tohoku on Sep 3 and in Tohoku on Sep 4, respectively.

By area, the weekly average of the 24-hour spot prices was at Yen 14.34 in Hokkaido, down Yen 0.20 from the previous week; Yen 13.28 in Tohoku, down Yen 0.68; Yen 15.93 in Tokyo, up Yen 1.72; Yen 15.13 in Chubu, up Yen 1.25; Yen 14.19 in Hokuriku and Kansai, up Yen 2.00; Yen 12.84 in Chugoku, up Yen 1.86; Yen 12.10 in Shikoku, up Yen 1.90; and Yen 12.84 in Kyushu, up Yen 1.89.

In the JEPX auction, the volume of offers was 1,200.27 mil kWh on a weekly average basis, down 2.7% from the previous week. Meanwhile, bids on a weekly average basis were down 3.2% to 1,175.06 mil kWh. The weekly average of trade volumes recorded 882.61 mil kWh, down 1.2%.

Power demand in nine areas of Japan during Sep 1-5 was a combined 14,164.26 mil kWh, down 2.2% from 14,487.19 mil kWh during Aug 25-29. The figure was up/down 6.8% from the corresponding period a year earlier, which was 13,259.55 mil kWh during Sep 2-6, 2024, after day-of-week adjustment.

Deals reported on TOCOM (Tokyo Commodity Exchange) during Sep 1-5 were as below.

Deals reported on EEX (European Energy Exchange) during Sep 1-5 were as below.

Prices for the second week of September were expected to hover higher in the first half of week. High temperatures of over-extraordinary hot day were expected in many places from Kanto through Kyushu on Sep 8-9, having a spillover effect on prices. From Sep 10 and onwards, however, temperatures were forecasted to turn lower, which would lead to soften prices toward the end of week. "It is no wonder that prices will hover at around Yen 15.00 for base load in Tokyo at the beginning of week. Scorching weather is coming again, which will stimulate buying interests. After that, easing hot temperatures are expected to lower prices at around Yen 13.00 in the latter half of week. In Kansai, prices will move Yen 1.0-1.5 below the level of prices in Tokyo," a source at a power producer and supplier said.