News

PG&E’s California Gas Transmission has made a change to the presentation of gas heating values on its Pipe Ranger Web site. This change will provide additional information and should minimize confusion regarding therm factor calculations.

Effective today, CGT will post seven weeks of weekly heating values on its Heating Value Web page versus four. This will provide customers the ability to calculate the therm factor for their recent billing period. Therm factors are used to convert the volume of gas metered (in hundreds of cubic feet) to energy units (Therms). The new presentation method replaces the previous method, where a therm factor was shown that was calculated using a four week heating value average. In the past some confusion occurred because therm factor calculations sometimes require a five week heating value average.

Calculating the Therm Factor
Although the therm factor is included on the CGT Detail of Bill, some customers may choose to calculate the therm factor in advance of receiving the bill. The therm factor applicable to a billing period is equal to the average of the weekly heating values within that billing period. To calculate the therm factor for a billing period, add the weekly heating values shown on the Heating Value Web page for those weekly dates that fall within the billing period, divide by the number of heating values for the period, then divide that number by 1000.

The Therm Factor Formula:
((Hv1 + Hv2 + Hv3 +Hv4) / Number of heating values) / 1000 = Therm Factor
Hv = weekly Heating Value

Sometimes It Takes Five
Noncore gas accounts are billed on a calendar month basis. Most calendar months will have only four heating values; however, months with five Mondays (January, April, July, October, and December in 2007) will have five heating values that must be averaged to obtain the applicable therm factor for a calendar month billing period. The formula in this case has five heating values: Therm Factor = ((Hv1 + Hv2 + Hv3 +Hv4 + Hv5) / 5) / 1000

A Therm Factor Calculation Example

To calculate the therm factor for the Billing period February 1-28 for BTU area code B02 use the heating values from the table above which are 2/26, 2/19, 2/12/ and 2/5.

The Therm Factor calculation is: ((1,017 + 1,017 + 1,018 +1,019) / 4) / 1000 = 1.018

If you have questions regarding therm factor calculations, please contact a CGT Account Services Representative.