Explaining Gas Billing with SAP Utilities

In gas billing, the measured operating volume of a gas is evaluated to determine the actual billing quantity. Each register of a gas meter is assigned a gas procedure that defines how the gas volume will be evaluated. Gas billing types include:

• According to standard cubic meters

  Operating cubic meters are converted into standard cubic meters using the gas volume correction factor.

• Thermal

  Operating cubic meters are converted into a heat quantity using the volume correction factor and the calorific value.

• Volumetric

  The operating cubic meters measured are billed directly.

In thermal gas billing, the measured operating cubic meters are multiplied by the volume correction factor to determine the standard cubic meters. In turn, the standard cubic meters are multiplied by the calorific value to determine the heating quantity (such as BTU or therms) that is to be billed.

In S/4HANA Utilities, the system determines the volume correction factor in the volume correction factor procedure. The calorific values are defined in the calorific value procedure. The volume correction factor procedure and the calorific value procedure combine to produce a gas procedure.

Volume correction factor procedure

The volume correction factors (VCFs) allow you to convert volumetric gas consumption into standard cubic meters. The VCF is determined using the following components: temperature, air pressure, measured pressure, and the gas law deviation factor. In the VCF procedure, the system determines which components of the VCF play an important role in gas billing. If you choose volumetric gas billing, you do not have to maintain the components and activities of the VCFs.

• Postal regional structure

  Regional data that influences billing for thermal gas billing can be stored in the postal regional structure. This data can be individually adjusted in the installation or installation structure.

• Installation

  The rate category defines the type of gas billing.

• Installation structure

  The gas procedure is defined here. It specifies how the calorific value and volume correction factor are determined.

• Register description

  The register description defines which factors are already taken into account for gas billing.

• Temperature

  The system either uses gas temperatures measured monthly or daily, or a fixed temperature.

• Gas procedures

  The gas procedures group the volume correction factor procedure and the calorific value procedure.

• Allocation data

  Here you can use the 'deviation' and 'default' fields to control how the gas month is to be defined. This is particularly relevant for entry of meter reading results.

• Volume Correction Factor

  • Air Pressure
  • Gas Temperature
  • Gas Pressure
  • Gas Law Deviation Factor, calculated using pressure and temperature

• Calorific Value

The gas law deviation factor is a ratio of the real gas factors of the gas in operating and standard conditions. It can be determined using the following methods:

• Specified for each device

• Calculated using pressure and temperature

• Standard temperature ST = 273.13 K

• Standard air pressure SP = 013.25 mbar

• Gas temperature T = ST + Gas temperature in °C

• Air pressure AP

• Actual pressure Act.P

• Operating cubic meters Operating volume

• Gas law deviation factor GLDF

• Volume correction factor Ratio between standard and operating volume

• Billing quantity Standard volume x Calorific value

SP and ST refer to standard physical conditions. In the metric system, the standard conditions in example 1 usually apply; in countries with non-metric systems, the standard conditions in example 2 can also apply. The constants To and ST are used to adjust the above formula so that you can enter the gas temperature t in the units of measure used in that country (such as degrees Celsius or Fahrenheit) into the corresponding temperature tables.

Metric system: Gas temperature in degrees Celsius. The following values apply: ST = 273,15 Kelvin and To = ST = 273,15 Kelvin. In the temperature tables, t is maintained in degrees Celsius.

English (imperial) system: Gas temperature in degrees Fahrenheit: The following values apply: ST = 520 Rankine and To = 460 Rankine (zero on the Fahrenheit scale). In the temperature tables, t is maintained in degrees Fahrenheit.

• Annual Air Pressure
• Air Pressure Measured each Month
• Arithmetic Average for the Billing Period
• Weighted Average for the Billing Period

Gas law deviation factor (GLDF)

The following options are supported for calculating the GLDF:

• Per device

  The defined GLDF is maintained at register level.

• Using pressure and temperature

  Here, you must maintain the GLDF table with a sufficient range of values of GLDFs and their corresponding pressure and temperature values.

• Using a user exit

  A user exit is called up and is provided with all the essential parameters such as pressure and temperature. The user exit returns the compressibility. For example, this allows you to use the GERG88 or AGA-NX19 procedure in the user exit.

• The GLDF not taken into account

Note that the GLDF is never calculated directly in S/4HANA Utilities. It must always be calculated using one of the above options.

• Arithmetic Annual Average
• Weighted Annual Average
• Arithmetic Average for the Billing Period
• Weighted Average for the Billing Period

Register

• Fixed Temperature
• Gas Procedure

Rate category

• Type of Gas Billing (Thermal, Volumetric, According to Standard Cubic Meters)

Regional Structure

• Default Value for Device Installations
  • Air Pressure Area
  • Temperature Area
  • Calorific Value District