I. Introduction
This briefing note has been prepared to summarise the amendments to secondary legislation published in the Official Gazette dated 29 December 2025 and numbered 33122, which directly affect the electricity market, aggregation, storage structures, notification and settlement rules, grid obligations and the implementation of the Renewable Energy Resources Support Mechanism (“YEKDEM”).
In this context, the amendments introduced by the following regulations have been reviewed:
(a) Regulation Amending the Electricity Market Balancing and Settlement Regulation (“Balancing Regulation”);
(b) Regulation Amending the Electricity Market Licensing Regulation (“Licensing Regulation”);
(c) Regulation Amending the Electricity Market Ancillary Services Regulation (“Ancillary Services Regulation”);
(d) Regulation Amending the Regulation on Storage Activities in the Electricity Market (“Storage Regulation”);
(e) Regulation Amending the Regulation on Aggregation Activity in the Electricity Market (“Aggregation Regulation”);
(f) Regulation Amending the Electricity Grid Regulation (“Grid Regulation”);
(g) Regulation Amending the Regulation on the Certification and Support of Renewable Energy Resources (“YEKDEM Regulation”).
Section II below provides an executive summary of these legislative amendments. Section III addresses the amendments on a regulation-by-regulation basis.
II. Executive Summary
The regulations published in the Official Gazette dated 29 December 2025 clarified the position of aggregation and storage structures within market processes, strengthened notification and settlement rules and updated certain fee and formula provisions in the secondary legislation of the electricity market.
Under the Balancing Regulation, portfolio and notification rules were tightened. For a legal entity holding a generation licence to add an eligible consumer to its portfolio under Article 30/A of the Balancing Regulation, it is now required that at least one settlement-based feed-in/withdrawal unit (“UEVÇB”) relating to at least one of the generation facilities in its portfolio be registered in its own name. Where an aggregation licence is obtained (or aggregation activity is added to a licence), the relevant market participant’s membership in a balancing responsible group is terminated; where the group is a “party”, the group is to be dissolved. For facilities that include storage or have more than one UEVÇB, the rules on which UEVÇB the meters and metering points are to be assigned to, and on how UEVÇBs are to be matched with one another, were clarified. In addition, the available capacity notification was defined; where incomplete or misleading notification of available capacity becomes habitual, or where untruthful notifications or transactions are detected in the Balancing Power Market (“DGP”) processes, a mechanism was introduced whereby the system operator, Türkiye Elektrik İletim A.Ş. (“TEİAŞ”), prepares a report and notifies the Energy Market Regulatory Authority (“EPDK”).
The installed capacity and settlement assumptions accepted in licensing and storage structures were made more explicit. The definition of “floating solar power plant (Yüzer GES)” was expanded; it was provided that, in transactions such as licence transfers, the validity of the EPDK Board approval is limited to a period determined for each transaction. The time and consequence regime in Renewable Energy Resource Areas (“YEKA”) processes was updated. For generation facilities with storage and stand-alone storage facilities, the accepted electrical installed capacity and maximum limits were taken as the basis for the energy that may be fed into the grid during the settlement period. Where these limits are exceeded, it was provided that action will be taken under Article 12 of the YEKDEM Regulation for the excess portion, and that the relevant energy will be subject to the consequences set out in Article 12 (such as exclusion from the support account or being treated as a free-of-charge contribution to YEKDEM).
In the Ancillary Services Regulation, certain coefficients and multipliers used in fee/obligation calculations were incorporated into the text of the regulation. In TEİAŞ’s capacity procurement processes, a rule was introduced requiring the tender specifications to be announced at least 90 days in advance. It was provided that, if the capacity registered in the aggregator’s agreement falls below the total capacity won in the capacity procurement, no capacity fee will be paid for the relevant month or months and the aggregator may not participate in activation procurement.
In the Electricity Grid Regulation, the addressee in the emergency provisions was updated to “owners of unlicensed electricity generation facilities”, the phrase “connected from the transmission system” in Article 65/1 was removed and the scope was thereby extended. The transition date for reactive power support obligations was postponed to 1 January 2027 and the mandatory values to be applied to certain groups of facilities (excluding the facilities of Elektrik Üretim A.Ş. (“EÜAŞ”)) were expressly determined (e.g. 15%/10%, and 10% for certain wind power plants (“RES”)).
In the Aggregation Regulation, a monitoring mechanism by Enerji Piyasaları İşletme A.Ş. (“EPİAŞ”) and quarterly reporting to EPDK were introduced to follow up the implementation of the prohibition on wholesale activity in aggregation.
In parallel with the amendments to the Storage Regulation, amendments relating to storage were also made to Articles 8 and 12 of the YEKDEM Regulation. Accordingly, it was provided that energy fed into the grid from the storage unit after exiting YEKDEM will not be taken into account in the calculation of the YEK fee. In addition, it was provided that a separate set of prices will apply to energy fed into the system after being stored in wind power plants and solar power plants (“GES”) with storage commissioned after 1 May 2023, whereas the plant’s own RES and GES prices will be the basis for energy fed directly into the grid. Finally, the settlement-based feed-in quantity (“UEVM”) used in the calculation of the total YEK fee and the applicable YEK price were differentiated according to whether the energy is fed into the system after being stored or directly. It was expressly provided that, for feed-ins above the accepted installed capacity and maximum limits, and for energy withdrawn from the grid, stored and fed back, the portion not included in the support account will be deemed a “free-of-charge contribution” for YEKDEM purposes.
III. Principal Amendments to the Regulations
A. Amendments to the Electricity Market Balancing and Settlement Regulation
The amendments to the Balancing Regulation aim at (i) placing aggregation and storage structures more clearly within the system of the Balancing Regulation, (ii) strengthening portfolio rules and notification procedures and principles, and (iii) updating imbalance cost calculations.
The amendments to the Balancing Regulation may be summarised as follows:
(a) For a legal entity holding a generation licence to add an eligible consumer to its portfolio under Article 30/A of the Balancing Regulation, it is now required that at least one UEVÇB relating to at least one of the generation facilities in its portfolio, or to at least one unit connected to such facilities, be registered in its own name.
(b) It was provided that, where an aggregation licence is obtained or aggregation activity is added to a licence, the relevant market participants’ membership in the balancing responsible group terminates, and that, where they are the “party” of the group, the group is to be dissolved.
(c) For facilities that include storage or have more than one UEVÇB, the rules on which UEVÇB the meters and metering points are to be assigned to, and on how UEVÇBs are to be matched with one another, were clarified.
(d) Restrictions were introduced regarding the participants that may be included in an aggregator’s portfolio. For example, it was provided that certain types of generation facilities may not be included in the portfolio and that a consumer may not be included in the portfolios of more than one aggregator at the same time.
(e) It was provided that notifications to be made under the DGP as a result of intraday market activities may not be such as to increase the need for code 1 (constraint management) instructions issued by TEİAŞ, as the system operator, to resolve transmission constraints.
(f) Article 69/A, added to the Balancing Regulation, separately defined the available capacity notification and provided that the maximum power that can be fed into or withdrawn from the system under current conditions must be notified by 15:30, taking technical conditions into account. Where incomplete notification, non-notification or reduction through fault/maintenance records of the available capacity becomes habitual, or where untruthful notifications or transactions are detected in DGP processes, TEİAŞ is to prepare a report and notify EPDK so that action can be taken under Article 16 of Electricity Market Law No. 6446.
(g) The framework for emergency instructions in Article 75 of the Balancing Regulation was extended and certain implementation principles were made more explicit. Accordingly, it was provided that emergency instructions may also be given to market participants whose portfolio includes unlicensed electricity generation facilities connected from the distribution system, in respect of such facilities, and that such instructions will be implemented starting from the facility with the largest electrical capacity in operation. It was also expressly stated that, where the settlement price of such instructions exceeds the maximum price limit, the maximum price limit will apply.
(h) With the paragraph added to Article 87 of the Balancing Regulation, additional preconditions were introduced for legal entities holding a generation licence that wish to make settlement-based bilateral agreement notifications through the Market Management System (“PYS”). It was made mandatory that at least one of the generation facilities, or one unit thereof, in the portfolio of such licence holder has been accepted by the Ministry of Energy and Natural Resources (“Ministry”) and that a UEVÇB associated with it is registered as of the time of application. Settlement-based bilateral agreement notifications made through the PYS were accepted as official values under Article 88/6 of the Balancing Regulation; the former reference to “invoice-based” was removed.
(i) It was provided that, in lawsuits filed and enforcement proceedings initiated against EPDK and/or the relevant ministry due to immovables required for projects subject to a pre-licence or licence (including expropriation, de facto expropriation or immovable property disputes related to the project), if the litigation costs and the amounts to be determined by the court, or the amount subject to the enforcement proceedings together with its accessories, are not paid on time, EPDK will notify the relevant legal entity granting it a period; and if payment is not made within that period, such amounts will be deducted from the advance and/or invoice receivables of the relevant legal entity and transferred to EPDK’s account, and these receivables will be collected with priority.
(j) The energy imbalance calculation formulas under the Balancing Regulation were revised; the coefficients relating to their implementation were determined by EPDK Board decisions.
B. Amendments to the Electricity Market Licensing Regulation
The amendments to the Licensing Regulation aim at (i) defining floating GES and clarifying its scope, (ii) making the EPDK Board approval time-limited in transactions such as the transfer of a licence or of usage rights, and deeming it invalid if the transaction is not completed within that period, (iii) making installed capacity and capacity parameters in storage structures and their effect on settlement more explicit, and (iv) updating the time and cancellation regime in YEKA processes.
The amendments to the Licensing Regulation may be summarised as follows:
(a) The definition of “floating GES” in the Licensing Regulation was expanded. Floating GES, which previously covered only water surfaces within the plant site of hydroelectric generation facilities with a reservoir or regulator, now also cover solar-based generation facilities that can be installed on the water surfaces of seas, dam lakes, artificial lakes and natural lakes (excluding drinking and utility water reservoirs, wetlands and the shore and coastal strips within the scope of the Coastal Law). The potential installation areas for floating GES have thus been expanded, while an express exception has been introduced for sensitive areas.
(b) Under Articles 5/3(b) and 5/3(c) of the Licensing Regulation, it was expressly provided that EPDK Board approvals given for the transfer of rights and obligations under a licence and for the change of hands of the usage right of a generation facility by way of sale, transfer or lease are not indefinite. Accordingly, if the transaction is not completed within the period determined by the EPDK Board after its approval, the approval will become invalid and the transaction may not proceed without obtaining a new EPDK Board approval. In this context, it was also specified that the period to be determined by the EPDK Board for the transfer of a generation facility by way of sale, transfer or lease may not be less than six months.
(c) The procedure and time regime for YEKA applications was revised. In Article 13 of the Licensing Regulation, YEKA applications were excluded from the scope of the general announcement and certain time provisions, and the fixed “45 days” references were removed and replaced by references to the periods determined in the YEKA legislation. It was further provided that (i) a YEKA pre-licence may be extended in line with the favourable opinion of the Ministry, and (ii) where the Ministry notifies EPDK that the YEKA Agreement has been terminated, the YEKA pre-licence and the YEKA generation licence will be cancelled.
(d) While the rule that no unlicensed generation application may be made for a generation facility site subject to a pre-licence or generation licence application has been preserved, it was provided that, where an unlicensed generation facility application intersects or overlaps with such site, action will be taken under the Regulation on Unlicensed Electricity Generation in the Electricity Market instead of returning the application.
(e) In pre-licence applications based on wind and solar energy, the rule for determining the connection region where the plant site falls within more than one connection region was updated, and it was provided that the connection region in which more than fifty percent of the plant site is located will be taken as the basis, taking into account the provincial boundaries of the General Directorate of Land Registry and Cadastre.
(f) The circumstances and conditions under which requests for changes to the plant site will be considered in pre-licence (Article 18) and licence (Article 24) amendments were re-regulated. It was also expressly provided that changes to the installed capacity or capacity of storage units in generation facilities with storage will also be deemed an “amendment”, and that such changes will be carried out under the Article 18 procedure at the pre-licence stage and the Article 24 procedure at the licence stage.
(g) It was provided that, in stand-alone electricity storage facilities established under a supply licence or an aggregator licence, the amount of energy that may be fed into the grid during the settlement period is limited to the maximum amount of energy corresponding to the accepted electrical installed capacity of the facility, and that, where this limit is exceeded, action will be taken under Article 12 of the YEKDEM Regulation in respect of the excess portion.
(h) It was expressly provided that the active output power that may be fed into the system in electricity generation facilities may not exceed the total electrical installed capacity of the units based on the main source for which provisional acceptance has been made. It was provided that, where energy is fed into the system above the generation corresponding to the accepted installed capacity, action will be taken under Article 12 of the YEKDEM Regulation in respect of the excess portion.
(i) It was provided that, in generation facilities with storage and generation facilities with an integrated storage unit, the amount of energy that may be fed into the system on a settlement period basis is limited to the amount of generation that can be made with the total electrical installed capacity of the accepted units based on the main source. It was also provided that the amounts of energy withdrawn from the grid and stored by these facilities will not be included in the relevant purchase calculation.
C. Amendments to the Electricity Market Ancillary Services Regulation
The amendments to the Ancillary Services Regulation aim at (i) making TEİAŞ’s tender/announcement structure more predictable in demand-side participation and capacity procurement processes, (ii) tightening the rules on market participants’ notifications and obligations and clarifying the notification principles, and (iii) clarifying the consequences to be applied in cases of non-compliance.
The amendments to this regulation may be summarised as follows:
(a) In the Ancillary Services Regulation, certain standard multipliers (such as ku/lu) were defined in line with the coefficient/multiplier-based calculation approach used in fee and obligation calculations. As a result, the formula variables used in calculating the capacity fee and similar amounts are now regulated under the regulation. It was also provided that certain unit prices and parameters will be determined by EPDK Board decision.
(b) The content and timing of TEİAŞ’s tenders and announcements regarding capacity procurement under demand-side participation were made clearer. For example, the obligation to announce the tender specifications at least 90 days in advance and the minimum information to be included in the announcement were regulated.
(c) The consequences of non-compliance with capacity obligations were clarified. It was provided that, if the capacity registered in the aggregator’s agreement falls below the total capacity won in the capacity procurement, no entitlement to the capacity fee will arise for the relevant critical month or months and participation in activation procurement will not be possible. In addition, certain existing periods were extended (for example, from 90 days to 120 days), and in certain processes the period and implementation were made subject to the periods and principles to be determined by TEİAŞ based on its system security assessment.
D. Amendments to the Regulation on Storage Activities in the Electricity Market
The amendments to the Storage Regulation appear to aim at (i) clarifying the possibility of installing storage at unlicensed generation facilities and the related settlement and payment consequences, (ii) detailing the connection structure, market participation and settlement assumptions for generation with storage and storage integrated into generation, and (iii) making the connection and settlement limits for stand-alone storage facilities more explicit.
The amendments to the Storage Regulation may be summarised as follows:
(a) The option of an “electricity storage facility established by unlicensed electricity generation facilities” was added to the storage structures in the regulation, and the framework for installing storage at unlicensed generation facilities was updated.
(b) It was made possible to install storage facilities at unlicensed generation facilities that have received a call letter under the Regulation on Unlicensed Electricity Generation in the Electricity Market and for which netting is carried out under Article 26 (and which meet the conditions of Article 37/6 of that regulation). In this context, it was provided that, where energy is fed into the grid from storage, no payment will be made for the portion of the excess energy remaining after netting that comes from storage; that, where the portion coming from storage cannot be measured, no payment will be made for the entire excess energy; and that such energy will be deemed a free-of-charge contribution to YEKDEM.
(c) For generation facilities with storage and facilities with a storage unit integrated into the generation facility, while the upper limit set for energy that may be fed into the grid on a settlement period basis was preserved, an exceptional flexibility was introduced for facilities whose main source has not been commissioned, in whole or in part. Accordingly, it was provided that, where the system operator deems it appropriate in terms of technical requirements and the conditions it determines are complied with, energy may be fed into the grid, limited to the accepted portion of the storage unit and storage facility and without exceeding the electrical installed capacity of the main source recorded in the generation licence. It was also provided that the participation of these facilities in ancillary services and the balancing power market will take place through the UEVÇBs with which they are associated.
(d) For generation facilities with storage and facilities with a storage unit integrated into the generation facility, an attribution rule was introduced as to which asset withdrawal/feed-in is attributed on a settlement period basis. Accordingly, it was provided that, where energy is withdrawn from the grid in the relevant settlement period, the withdrawal will be deemed to have been made primarily by the storage unit (if the storage unit has a withdrawal), and where energy is fed into the grid, the feed-in will be deemed to have been made primarily by the storage unit (if the storage unit has a feed-in).
(e) Connection configurations for stand-alone electricity storage facilities were separately defined, and the amount of energy that may be fed into the grid on a settlement period basis was limited so as not to exceed the maximum amount of energy that can be fed with the electrical installed capacity of the accepted storage facility. It was provided that, where this limit is exceeded, the excess energy will be deemed to have been generated by the incumbent supply company participating in YEKDEM and will be taken into account as a free-of-charge contribution to YEKDEM.
(f) With respect to facilities considered to be storage integrated into a consumption facility, the legal entity of an industrial zone was included in the scope in addition to the legal entity of Organised Industrial Zones (“OSB”); it was thus provided that electricity storage facilities established by these legal entities within the boundaries of OSBs and industrial zones will be considered storage integrated into a consumption facility under Article 6.
(g) In terms of connection and technical structure, new connection configuration annexes were added to the Regulation (ANNEX-1a, ANNEX-1b, ANNEX-1c, ANNEX-1ç, ANNEX-2, ANNEX-3a, ANNEX-3b), and certain definitions and references were aligned with this new annex structure.
E. Amendments to the Regulation on Aggregation Activity in the Electricity Market
The amendment to the Aggregation Regulation constitutes a new supervisory step for aggregators. The amendment provides that whether aggregators carry out wholesale activity will be monitored by the Market Operator (EPİAŞ) and that the report containing the monitoring results will be submitted to EPDK on a quarterly basis. Thus, while the prohibition on wholesale activity set out in Article 5/4 has been preserved, an institutional monitoring and reporting mechanism for following up the implementation of the prohibition has been expressly defined.
F. Amendments to the Electricity Grid Regulation
The amendments to the Electricity Grid Regulation aim at (i) extending the scope and area of application of certain provisions by simplifying them, and (ii) extending the transition period for reactive power support obligations and making the mandatory values to be applied to certain groups of facilities clearer.
The amendments to the Electricity Grid Regulation may be summarised as follows:
(a) The wording of sub-paragraph (d) of Article 64/1 of the Electricity Grid Regulation was updated and the sub-paragraph was re-regulated with “owners of unlicensed electricity generation facilities” as the addressee.
(b) The phrase “connected from the transmission system” in Article 65/1 of the Electricity Grid Regulation was repealed. As a result, the application of the relevant provision has been framed more generally, without being narrowed according to whether the connection is from the transmission system.
(c) Under Provisional Article 5/1, the transition period was extended and the reactive power values were clarified. Accordingly, the transition date was postponed from 1 January 2026 to 1 January 2027.
(d) Excluding EÜAŞ facilities, the mandatory reactive power values for certain older generation facilities were set at 15% of the nominal active power in over-excited mode and 10% of the nominal active power in under-excited mode. For RES that concluded a connection agreement with TEİAŞ before 24 September 2008, it was stated that the mandatory values are 10% of the plant’s installed capacity in both over-excited and under-excited modes. It was provided that the reactive power support service obligations of EÜAŞ facilities within this scope will be determined under a protocol to be concluded between EÜAŞ and TEİAŞ.
G. Amendments to the Regulation on the Certification and Support of Renewable Energy Resources
The amendments to the YEKDEM Regulation regulated and updated (i) how energy fed into the grid after being stored at facilities with storage will be taken into account in YEK/YEKDEM calculations, (ii) the price structure applicable to post-storage feed-in at RES/GES with storage, and (iii) certain fee and calculation provisions, in particular the total YEK fee and the YEK fee.
The principal amendments to the YEKDEM Regulation may be summarised as follows:
(a) With the provision added to Article 8 of the Regulation, it was provided that, after generation facilities with storage and facilities with a storage unit integrated into the generation facility exit YEKDEM, energy generated and stored during the YEKDEM period and subsequently fed into the grid will not be taken into account in the YEK UEVM calculation.
(b) Furthermore, it was provided that, for wind-based generation facilities with storage commissioned after 1 May 2023, the price in sub-paragraph (e) of ANNEX-1 to Presidential Decision No. 7189 will be the basis for energy fed into the system after being stored in the storage unit, whereas RES or GES prices will apply according to the source type where the energy is fed into the system without being stored. Integrated storage units within generation facilities were designated as an exception to this provision.
(c) In the calculations on which YEKDEM payments are based, the UEVM and the applicable YEK price were updated so as to be determined according to whether the energy is fed directly into the grid or fed into the grid after being stored.
(d) In addition, feed-ins above the accepted installed capacity and maximum generation limit, and energy withdrawn from the grid, stored and fed back, were excluded from the support account and made subject to the “free-of-charge contribution” consequence.
(e) The calculation of the YEK fee (Article 18) was revised. The YEK fee formula was regulated so as to also include YEKDEM revenue. In addition, the provision on the ratio by which the domestic contribution fee relating to capacity increases will be calculated was updated.
(f) It was provided that, where generation is made and fed into the system above the finalised day-ahead generation/consumption programme (“KGÜP”) on official holidays other than Sundays, the portion above the KGÜP will not be included in the YEK UEVM calculation and no YEK fee will be paid for that portion.
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