The Component Electricity_Tariff_CHP_Surcharge
The component Electricity_Tariff_CHP_Surcharge represents the support mechanism of the CHP surcharge. The calculations are based on the boundary conditions described by the Federal Office of Economics and Export Control (Bundesamt für Wirtschaft und Ausfuhrkontrolle, BAFA).
Do not confuse the CHP surcharge with the feed-in tariff, which is included in the Electricity tariff component.
Component Template
The Electricity_Tariff_CHP_Surcharge.e-ctpl component template is located in the Component template library folder Electricity Supply.
Integration Into a Scheme
How the Component Works
The Electricity_Tariff_CHP_Surcharge.e-ctpl component maps surcharges for the operation of a CHP-eligible installation or an EEG plant. CHP stands for combined heat and power generation, e.g., a block-type thermal power station. EEG is the abbreviation of the German Renewable Energy Sources Act (German: Erneuerbare-Energien-Gesetz), on the basis of which such installations are supported. There are separate forms for combined heat and power plants (CHP) and for wind power and PV systems (Renewable power plant).
The component Electricity_Tariff_CHP_Surcharge does not only refer to one generation unit, e.g., a CHP. Otherwise it would be sufficient to enter a surcharge per kilowatt hour in a simple Electricity Tariff component. It also balances the extent to which the electricity generated is fed into the grid or used for own consumption. In the case of own use, the EEG surcharge that may have to be payed by the end consumer is calculated depending on the tariff selected.
In the following, the Input data of the component are presented in detail.
Electricity Demands and Grids
Under the tab Electricity demands and grids, enter all electricity consumers to be balanced that are supplied by the CHP or renewable power plant and grids into which the CHP or renewable power plant feeds (see following figure).
Select the demands and grids from the drop down lists. You can add additional power consumers and grids using the 
plus sign.
The assignment of electricity demands and grids ensures compliance with the balancing rules. This also applies to the rules which may be disadvantageous because of the EEG surcharge to be paid, e.g., the priority of covering own electricity demand over feeding electricity into the grid.
Within a component Electricity_Tariff_CHP_Surcharge, the capacity of the generators and demands is totaled. Specifications that, for example, CHP 1 may only cover own demand 3 cannot be taken into account.
If different circuits are to be considered, a separate Electricity_Tariff_CHP_Surcharge component must be created for each circuit in the scheme.
Otherwise the error message 8125 appears. This also applies to the Electricity_Supplier component. A particular electricity supplier may not occur twice. Therefore, if necessary, an additional Electricity_Supplier component should be added for an additional circuit.
The remuneration is calculated only for the installations declared in the List of electricity demands using self-generated electricity. If an EEG or CHP plant is connected through the grid to a consumer which is not declared in the list of electricity consumers, no remuneration will be calculated for the power consumed by this consumer.
CHP
Under the CHP tab, define the combined heat and power plants eligible for promotion. In most cases, this is a CHP unit. However, a diesel generator or a gas turbine with heat recovery can also be specified.
Under the heading Cogeneration of heat and power unit, select the CHP or gas turbine or similar to which the input data relate from the drop-down list behind Reference to CHP (see following figure).
If no EEG or CHP component is selected, error message 8315 indicates this:
A model error has ocurred in component Electricity tariff CHP surcharge: Missing connection to power plant: No component is chosen in ‘Input data/Reference to CHP’. Please choose one or remove the item.
Type of Cogeneration Tariff
The drop-down menu behind Type of cogeneration tariff allows you to select 2020, 2021, 2023, and Individual input (see following figure).
The menu adapts depending on the selection made. With Individual input, you can make all entries individually.
Entering the CHP nominal power may result in the form being adapted, as the necessary input parameters depend on the nominal electrical output.
Combined Heat and Power Act (KWKG) 2023
Under Kind of own use you can choose:
The form adapts according to the input and shows the further input parameters. Depending on whether it is a new, modernized, or retrofitted CHP system, the number of the full load hours eligible for surcharge varies between 6,000 and 30,000 (§ 8). Under Condition of the plant (§ 8) you can choose:
Select the following optional bonuses each by clicking in the box:
The form adapts and displays the other input parameters.
Fixed Remuneration Rate
If the CHP is eligible to a fixed remuneration rate, this remuneration rate is automatically integrated in the calculation without you having to enter it separately. The remuneration rates are calculated in accordance with the regulations published by the Federal Office of Economics and Export Control (BAFA). Further information on the electricity remuneration for CHP plants (German: Stromvergütung für KWK-Anlagen) can be obtained directly from BAFA.
Tender Procedure
The remuneration within the scope of the tender procedure must be entered individually in ct/kWh in the Cogeneration addition (feed-in, § 7) field. It can also be stored as a time series.
Resulting Tariff Constituents
Based on your selection, the resulting tariff constituents are displayed in a Preview: Cogeneration addition (own consumption) and Cogeneration addition (feed-in, § 7).
The field for the Annual remunerated full load hours can be edited, because the CHP remuneration is not only related to the term, but is also limited to an annual number of full load hours.
Full Load Hours
For the 2021 and 2023 CHP tariffs, the full load hours (FLH) eligible for the surcharge must be entered in the Input data as estimated value. The number of the Eligible full load hours (German: zuschlagsberechtigte Vollbenutzungsstunden, zVBh) varies for the size of the installations. Under Full load hours for cogeneration addition, you specify the total number of full load hours for which the CHP surcharge is granted in relation to the term. The duration of the remuneration depends on the size of the systems, e.g., in the tendering procedure for a maximum total of 30,000 full utilization hours or, in the case of an innovative CHP system, for 45,000 full utilization hours.
If the CHP unit has already been in operation for a longer period of time, you can specify the Already remunerated full load hours.
Only the actually subsidized full load hours that are fed in and thus remunerated with surcharges count as full load hours eligible for surcharge. Self consumed electricity may not be entitled to a surcharge and is then not included in the eligible full load hours.
The full load hours eligible for surcharges are divided proportionally in relation to the fed-in and self-consumed electrical power, e.g., when using an SLP meter (SLP short for standard load profile). Check the box next to Time-accurate allocation of FLHs to allocate the full load hours eligible for surcharges to the exact hour according to the operating mode of the fed-in and self-consumed power, e.g., when using an RLM meter (RLM short for recording power measurement). The distinction only has an effect if the system produces more than the remunerable FLHs (e.g., more than 3,500 h/a) and both feed-in and self-consumption are remunerated. Which method is used must be clarified with the relevant electricity grid operator.
The KWKG 2023 specifies the following grading for the calendar years: 2021/22 5,000 full load hours each, 2023/24 4,000 full load hours each, 2025 3,500 full load hours, 2026 3,300 full load hours, 2027 3,100 full load hours, 2028 2,900 full load hours, 2029 2,700, and from 2030 2,500 full load hours each.
The number of full load hours for which the CHP surcharge is granted in total refers to the entire operating time over several years. It is set at between 6,000 and 60,000 hours for CHP plants with fixed remuneration (less than 500 kW or greater than 50 MW), depending on the condition of the plant (§ 7 of the Combined Heat and Power Act–KWKG 2023). For plants participating in the tendering procedure, the duration of the remuneration is 30,000 full load hours or 45,000 for innovative CHP systems (§ 19 of the CHP Tendering Ordinance, German: KWK-Ausschreibungsverordnung, short KWKAusV).
Positive EEX Price
In the drop-down menu, select whether the Surcharge is constantly received or only with positive EEX price received.
For plants up to 1 MW and over 50 MW rated electrical capacity, the CHP surcharge is only granted if the electricity price on the exchange is positive; if the electricity price is negative or 0, the surcharge does not apply. To take this option into account, store a time series with the exchange electricity prices here or use the values for the electricity price from the Economic base data. Default time series for CHP remuneration eligibility with positive EEX prices are available in the ETA.
The values of the time series are checked for their sign–if the electricity price is negative or 0, no CHP surcharge is granted; if it is positive, the surcharge is granted. If the exchange electricity price is not specified as a time series but with a constant positive number, the surcharge is granted for the entire period.
Additional Feed-In Tariff
Under the heading Consider only cogeneration remuneration or additional feed-in compensation, you can choose between the two options A and B:
Option B takes into account a feed-in tariff granted by the grid operator in addition to the CHP surcharge. This can be entered in the additional input field Feed-in remuneration (excess power) that opens (see following illustration) or also mapped in the Electricity tariff component. Only enter it once so that it is not calculated twice.
It is also possible to use actors here. You can select the Debited and the Benefited stakeholder.
Former CHP tariffs
The CHP tariffs that applied from 2020 and 2021 can also be selected.
The following input data menu opens for the 2020 tariff.
Until July 1, 2022, the electricity allocated to electricity demands using self-generated electricity (own use) was not only not remunerated, but was also subject to the EEG surcharge incurred by the end consumer. Exceptions to this were, for example, systems with a peak output of less than 10 kWp and self-sufficient stand-alone systems without a grid connection.
By clicking in the respective box, you can determine whether the system is in the emission trade and whether it substitutes a coal-fired system.
The Resulting tariff constituents are added from this information on the basis of the applicable regulations and displayed under the heading of the same name.
Two different remuneration methods are assigned to the capacity categories (see table below).
| Nominal Electrical Capacity of the CHP | Retrofitting | Remuneration Method |
|---|---|---|
| Up to 1 [MW_el] | fixed remuneration rate | |
| Greater 1 [MW_el] up to 2 [MW_el] | retrofitted plant | fixed remuneration rate |
| Greater 1 [MW_el] up to 2 [MW_el] | not retrofitted | tender procedure |
| Greater 2 [MW_el] up to 50 [MW_el] | tender procedure | |
| Greater 50 [MW_el] | fixed remuneration rate |
The EEG Surcharge (EEG reallocation charge) for own electricity use and the proportional payment (Share of the EEG surcharge) can be specified individually for each application under the heading Reallocation surcharge payable for own consumption. You can select the Debited and the Benefited stakeholder (see following figure).
Renewable Power Plant (Renewable Energy Sources Act system)
Under the Renewable Power Plant tab, first select the plant from the drop-down menu that is associated with the EEG remuneration or surcharge, for example a wind power or PV system, and then enter its EEG remuneration and surcharge rates, if applicable with details of the debited and benefited stakeholders (see following figure).
Managing of Scenarios
The Cogeneration addition is only granted for a limited period depending on the full load hours. Because the suspension of the remuneration can affect the operation of the systems, it is advisable to insert a new support year after the Cogeneration addition has expired.
Example
With support years 2025, 2035, and 2045 the first simulation shows that the CHP surcharge expires in 2039. Add another support year 2040.
Output Data
The optimum distribution of electricity generation into electricity fed into the grid and own electricity is displayed as a result in the output data. The revenues and any EEG surcharge to be paid are shown (see following figure).
Structural Optimization
You can only use the component Electricity_Tariff_CHP_Surcharge in structural optimization to take into account the remuneration of a CHP or EEG structural optimization component (for example, CHP_Opt) to a limited extent. This is indicated by model message 8506.
Because the size of the plant is not yet known before the simulation, the corresponding scale prices cannot be taken into account in the Electricity_Tariff_CHP_Surcharge. To carry out the structural optimization, select Individual input as the Type of cogeneration tariff and enter an estimated remuneration price. A simulator warning that the actual size of the CHP does not match the selection can then be ignored.
