CGT’s Composite Temperature Calculation Just Got Better
Monday, July 07, 2008
Good day, sunny San Jose! California Gas Transmission meteorology personnel keep trained eyes on the weather and they know if it is overcast in Oakland, rain-free in Redding or fair in Fresno. Recently, CGT improved its gas system composite temperature forecasting method by adding an additional weather station data point to the calculation. Extensive testing by CGT indicates that the new composite temperature methodology improves gas demand forecasts.
CGT uses the system composite temperature in addition to other information to estimate gas demand on the system. Demand and supply forecasts are used to create the System Inventory Forecast. When the System Inventory Forecast indicates pipeline inventory is trending toward the upper or lower limit, an Operational Flow Order may be announced. The composite temperature forecast is shown on Pipe Ranger's Current Pipeline Status page on the top line of the daily plan .
How It’s CalculatedThe PG&E system composite temperature forecast is based on the weighted sum of the average daily temperatures at six sites: Sacramento, San Jose, Oakland, Fresno, Redding and Salinas. An example is shown in the following table.
|Weather Site||Average Temperature||Weight||Avg Temp x Weight|
|San Jose (New)||66.3||0.28400||18.8|
|System Composite Temperature||68.6|
The revised composite temperature forecast methodology reflects our commitment to continually improve processes and service to our customers. If you have additional questions regarding the system composite temperature, please contact a CGT Account Services Representative.
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