Türkiye’s Transparency Platform from 1 January 2027: what is added, removed and changed

From 141 to 151

With decision 14968 of 15 October 2026, EPDK has redrawn the list of data that must be published on the EPİAŞ Transparency Platform. The decision appeared in the Official Gazette on 20 October, takes effect on 1 January 2027 and replaces decision 10711, which has applied since 2022. The list covers the electricity, natural gas and renewable guarantee-of-origin (YEK-G) markets, and the number of items rises from 141 to 151.

The change looks technical, but it reaches price formation directly. Intraday bids, imbalance forecasts, PPA pricing and investment models all rest on data drawn from this platform. Which data becomes faster, which is aggregated and which is no longer mandatory will leave a mark everywhere from the trader’s screen to the investor’s feasibility study.

Two platforms, two regimes

The decision rests on the Regulation on Transparency and Market-Distorting Behaviour in Energy and Environmental Markets, published on 14 February 2026. The regulation splits market data into two channels. Price, volume and system data stay on the Transparency Platform. Company-specific information that could move prices, such as a plant outage, maintenance or commissioning, will be disclosed on the Inside Information Platform (DBP) operated by EPİAŞ.

Decision 14967, published the same day, sets 19 items of minimum information to be disclosed on the DBP. That is why the outage, planned maintenance and interconnector notices of the old list do not appear in the new transparency list. The information does not disappear; it moves into a disclosure regime backed by fines.

The timetable has slipped once. The regulation was originally due to take effect on 1 June 2026; an amendment on 23 May 2026 moved the whole regulation, with no article carved out, to 1 January 2027. The October decisions are aligned with that date.

Mapping the new list

Of the 151 items, 103 concern electricity and 48 natural gas. On the electricity side the weight is on organised markets: the day-ahead market (GÖP), intraday market (GİP), electricity futures (VEP), balancing power market (DGP), YEK-G, ancillary services, bilateral contracts and imbalance together account for 60 items. Storage appears as a separate category for the first time.

Figure 1 Items per category in the new list

Electricity markets

60

Natural gas markets

34

Natural gas transmission

14

YEKDEM

11

Electricity generation

10

Electricity transmission

10

Electricity consumption

9

Dams

2

Electricity storage

1

We matched the 141 items of the old list one by one against the new list. 56 items stay essentially the same, 71 change in timing, resolution or scope, 8 are dropped entirely and 6 move to the Inside Information Platform. Some of the changes are formal: intraday and futures series are now defined per contract rather than per hour.

Figure 2 Where do the 141 items of decision 10711 go?

Essentially unchanged

56

Timing, resolution or scope changed

71

Dropped from the list

8

Moved to the Inside Information Platform

6

The provisional PTF, first KGÜP version, AUF, YEKDEM UEVM and unlicensed generation are already published on the platform; what is new is the obligation to publish them. We found no counterpart in today’s API for the storage report, the KGTP or the TEİAŞ installed capacity series.

Faster data

Balancing data becomes markedly faster. Up-regulation (YAL) and down-regulation (YAT) instruction volumes are today mandatory the next day (D+1) at hourly resolution; under the new list they will be published on the same day (D) per DGP settlement period. Mandatory publication of real-time generation by plant also moves from D+1 to D.

For the system marginal price (SMF), system direction and real-time consumption the change is mostly formal. The old list set five hours (H+5) for SMF and system direction and two hours (H+2) for consumption; the new list only says “same day”. That is a tighter definition for the last hours of the day and a looser one for the first.

Slower and aggregated data

Some data, on the other hand, becomes slower or more aggregated. The most striking case is cross-border trade: import and export volumes nominated by market participants are today published before delivery (D−1); under the new list they move to after the end of the month (M+1).

Reducing dam data to a national total matters for hydro-heavy portfolios. The fill level of individual reservoirs was a key input to regional generation and price expectations. Total active water and its energy equivalent are enough for the system as a whole, but not for forecasting the behaviour of a single plant or basin.

Ancillary services also need clarification. The new list gives D−2 as the publication time for primary and secondary frequency control prices and volumes; the old list said D−1. We have not seen any change to the timing of the capacity auction. How the wording will be applied will become clear with EPİAŞ’s first implementation.

What is dropped

Article 6 of the regulation prohibits publishing individual data that reveals a participant’s identity, except where it matters for the market as a whole. The new list applies this principle. Organisation-level day-ahead and intraday matches, participant-level bilateral volumes and hourly imbalance by balance responsible group (DSG) are dropped and replaced by totals.

The new list cuts data on “who did what” and speeds up data on “what is happening in the system”.

Leaving the list does not mean the data disappears at once. EPİAŞ may keep publishing some of these series voluntarily, but after 1 January 2027 it has no obligation to do so. For organisation-level series, the regulation’s explicit ban makes continued publication unlikely. For analyses that read competitor behaviour and portfolio positions from these series, a data source is closing.

Outage data: from 10 MW to 30 MW

The largest change concerns outage and maintenance notices. Under list 10711, every plant with an installed capacity of 10 MW or more had to report in real time the capacity unavailable because of an outage or unplanned maintenance; these notices appear today among the market messages on the platform.

Under decision 14967 this information moves to the Inside Information Platform and the yardstick changes. The threshold is no longer installed capacity but the change in capacity: 30 MW or more per facility, 50 MW or more per portfolio. The deadline is one hour at most. Events above the threshold are deemed capable of moving prices; failing to disclose them carries a fine of up to 2,509,800 TL at 2026 amounts.

The change cuts both ways. A 20 MW partial outage at a large plant will no longer be disclosed automatically, and outages at small wind and solar plants may become invisible. In exchange, every event above the threshold will be disclosed within an hour, with structured fields for facility, MW, start, expected end and cause, and under the risk of a fine. The portfolio threshold also captures multi-site events that stay below the threshold plant by plant but affect the system in total.

We cover the details of the disclosure regime, the market-distorting behaviour bans and the obligations of plant owners in our article “The one-hour rule: Türkiye’s inside information and market abuse regime”.

What data users should do

For anyone using the platform through its API, 1 January 2027 is a migration date. Intraday, futures and gas series are defined per contract; data models built on an hourly assumption may need to move to a contract key. Reports that rely on dropped series need a fallback source.

For investors

The right question is not “is more data coming?” but “is the data I decide on faster and more reliable?”. On the balancing side the answer is yes: same-day YAL and YAT instructions and plant-level generation feed imbalance and intraday strategies. Putting fines behind outage information narrows the information asymmetry; the head start large portfolios gain from their own outages gets shorter.

On the loss side are hydrology, cross-border flows and constraint data. All three were important inputs for investors modelling regional price spreads and constraint risk. Storage investors, on the other hand, get an official storage fleet series for the first time. The pace of competition, the largest uncertainty in battery revenue, can now be tracked monthly and by technology with official data.

At Frekans we produce our monthly Market Outlook reports and plant analyses from Transparency Platform data. Every series these reports use remains on the new list; we are completing the work to move intraday and futures series to the contract-based structure and outage data to the Inside Information Platform before January 2027. For projects at the investment stage we model the coarser dam and constraint data as an additional uncertainty in regional price and constraint scenarios.