L/H-gas conversion

For a secure, high-quality natural gas supply that’s fit for the future.

In order to cope with the decline in L-gas availability, the service areas currently supplied with L-gas have to be converted to H-gas. To this end, the gas transmission system operators have developed a conversion concept which is regularly updated in cooperation with the distribution system operators affected.

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As part of the planning process, the supply situation for L-gas is continuously analysed and assessed against demand. The conversion schedule as currently planned is described in the Gas Network Development Plan (NDP) and the NDP Implementation Report. The current NDP status can be found here. More detailed information on L/H-gas conversion at all TSOs can be found in the TSO gas database.

Where will the conversion take place?

The process affects consumers in northern and western Germany, who are still supplied with L-gas. They account for some 25 percent of the German gas market. The conversion to high-calorific natural gas already started in May 2015. Between five and 5.5 million gas appliances used by domestic, commercial and industrial gas customers have to be adjusted by 2030 so that they can cope with the higher energy content of H-gas. All measures are designed to ensure the quality and security of future natural gas supplies

Market area conversion levy

This levy regulates the nationwide allocation of the costs incurred by network operators in switching from L-gas to H-gas. The levy is charged in addition to the network charges at the exit points to

directly connected end users
downstream network operators
storage facilities and
at exit points located at cross-border and market area interconnection points

According to Section 19a of the Energy Industry Act (EnWG), the costs incurred as part of a market area conversion are to be borne by all gas grids in Germany. This cost allocation is done by using a cost compensation model according to which the costs of the conversion process are passed on to the end user. In simplified terms, the operators of the grids converted to H-gas (usually distribution system operators) report their conversion costs to the upstream transmission system operators. According to Section 19a (1) EnWG and Section 8 (1) of the Cooperation Agreement (KoV), the first step is for the transmission system operator to initiate the gas quality conversion process. If the network operator then changes the gas quality, he has to initially bear the related costs. The costs are subsequently passed on in accordance with the terms of the KoV, so that they are ultimately borne by the end users (cf. Section 19a (1) EnWG and Section 10 (3) KoV). Cooperation partners reporting a revenue surplus from the conversion levy will reimburse the difference between their costs and their revenues on a monthly basis to cooperation partners recording a revenue shortfall, so they essentially make compensation payments to transmission system operators with a cost surplus.

Information on conversion levy

According to the Gas Cooperation Agreement, Section 10 Paragraph 6, the transmission system operators are obliged to publish the updated nationwide conversion levy in €/(kWh/h) on October 1 of each year.

The following values were determined nationwide:

Market area conversion costs nationwide 2025 ACCORDING to plan/actual comparison 2023: €193,028,853.69
Sum of the remaining expected booked or ordered annual exit capacity of the networks nationwide in 2025: 287.526.486 kWh/h/a
Specific market area conversion levy nationwide in 2025: 0.6711 €/kWh/h/a
Actual conversion costs nationwide in 2023: €222,394,817.42

The costs are reported to OGE via the contract management system VMS.

Conversion dates for OGE pipeline network at a glance

For more information about the conversion dates, click here.

According to the Market Area Conversion Guide ("Leitfaden Marktraumumstellung"), the List of Metering Point Designations shows the conversion year as per the Network Development Plan, the expected technical conversion date and the conversion date used for balancing purposes.

The dates are defined as follows:

Technical conversion date
The technical conversion date is the date on which H-gas is fed into the transmission system operator’s network segment to be converted to H-gas.

Forecast date for gas quality change at the network interconnection point
The date of the change in gas quality at the network interconnection points between the transmission system operator and the downstream network operators is forecast together with the directly connected downstream network operators and the directly connected special end user affected by the changeover based on the technical conversion date.

Conversion date for balancing purposes
The conversion date used for balancing purposes is the first day of the month from which all allocation values are exclusively reported into H-gas balancing groups.

Accrual/deferral key date
The accrual/deferral key date is the point in time from which the H-gas is actually available to the end user. This date is used by the network operator for internal processes (for example, meter reading, accrual/deferral for billing processes). The network operator will determine this date based on the time at which the transmission system operator feeds H-gas into the system at the interconnection point shared with the directly connected downstream system operator. For SLP exit points the meter reading must be recorded on the accrual/deferral key date or within 10 working days after the accrual/deferral key date.