Utility Bill Calculator Demonstrator Workbook

The Utility Bill Calculator demonstrator is a Microsoft Excel 2007 workbook that can help you calculate a utility bill for any of the three Investor Owned Utilities in California: PG&E, SCE, and SDG&E. The spreadsheet makes use of the Clean Power Research Utility Bill Calculator and PowerTariffs web services, so you must be connected to the Internet in order for it to work properly.

Getting Started
Start by downloading and installing the workbook. You can download the Utility Bill Calculator Demonstrator installation package from the download page.

Once you've installed the bill calculator add-in, you'll notice that the workbook contains four worksheets: Utility Bill Calculator, Load Data, Utility Bill Summary, and Utility Rates. The Utility Bill Calculator worksheet contains instructions, support information, and the end user license agreement. Initially, the Load Data sheet is populated with sample demand data and the Utility Rates sheet contains some of the PG&E rates, while the Utility Bill Summary sheet is empty.

Input Options
To calculate your own utility bill, you must replace the information on the Load Data sheet with your own information.

Start by selecting the appropriate rate from the Utility Rate drop down list. If your utility rate does not appear, you can use the Rate Finder tool to look up a rate by zip code. To use the Rate Finder tool, enter the zip code for the location where the demand data was measured. Check the Commercial and/or Residential boxes to indicate the type of rate. Click the Find Rates button. The spreadsheet will obtain the available rates over the internet and update the drop-down list. After this is done, the correct rate can be selected from the drop down Only rates for the three California investor owned utilities will be displayed. In addition to selecting your utility rate, you can also select the demand time interval, demand interval convention, demand interpolation, demand unit.

Demand time interval indicates the amount of time between each demand measurement date/time. Demand interval convention tells the calculator whether the measurement date/time represents the starting time of the interval, the midpoint of the interval, or the end of the interval. This feature is not yet active in the utility bill service. It's assumed that the measurement date/time represents the end of an interval.

Demand interpolation indicates how gaps in the demand data are treated. Currently, the data submitted must be complete (gapless). If you have hourly data, every hour for every period must be included.

Demand unit indicates whether the values in the Demand column (column C on the Load Data worksheet) represent kilowatts (kW) or kilowatt hours (kWh).

If you are calculating a bill for a net metered rate, you can enter an NEM Carryover value to report any net metering credit from the billing cycle just prior to the earliest billing cycle on the Load Data worksheet.

Entering Load Data
In addition to selecting the appropriate input options, you will need to provide load data for the billing cycles over which you wish to calculate your utility bill. In the Billing Cycle column (column A), starting at row 14, fill in the name or number that identifies the billing cycle in which the energy usage occurred. In the Demand Measurement Date and Time Column (column B), starting at row 14, fill in the date and time that the demand measurement was made. In the demand column, enter the measured demand value in kW or kWh. Continue this process for each demand measurement in each billing cycle that you have demand data for, changing the Period Identifier value as needed. Demand measurements entered should represent evenly spaced intervals of one hour, 30 minutes, or 15 minutes.

Click the Add-Ins tab in Excel to display the ribbon containing the Rate Finder and Utility Bill Calculator tools. Next, click the button labeled, "Calculate Utility Bill." The utility bill for the load data on the Load Data sheet will be calculated and the results will be displayed on the Utility Bill Summary sheet, which will automatically be made active, and on row two of the Load Data sheet, in the results section. Calculating a utility bill is fairly quick, but uploading load data to the calculation service can take a while, even over a broadband Internet connection. A year's worth of hourly load data, for example, can take 5 to 10 seconds.

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