Due to the publication of fuel prices from April 2012 to June 2012 (trade statistics prices for crude oil, liquefied natural gas (LNG) and coal published by Ministry of Finance Japan), a fuel cost adjusted unit price for September 2012 is fixed as per enclosure.
According to the electricity rate raise to be effective on September 1, the preconditions for the fuel cost adjustment will be revised along with the changes of power generation composition and fuel price (Refer to Appendix 3 for revisions to be made).

Fuel cost adjustment system:
"Fuel cost adjustment system" is a system designed to automatically adjust monthly electricity fees based on fluctuations in (actual recorded) fuel prices for crude oil, LNG and coal.

http://www.tepco.co.jp/en/customer/guide/fuelcost-e.html

Appendix: Fuel Cost Adjustment in Electricity Fees for September 2012 (PDF 23.0KB)
Attachment 1: Calculation of Fuel Cost Adjusted Unit Price and Electricity Fees for September 2012 (PDF 49.2KB)
Attachment 2: Calculating Electricity Fee for each contract ampere in September 2012 (PDF 17.2KB)
Attachment 3: Preconditions for Fuel Cost Adjustment (PDF 53.8KB)