Due to the publication of fuel prices from July to September 2009 (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 December 2009 is fixed as per 
enclosure.

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 December 2009 (PDF 17.8KB)