The Greek balancing market is based on a central dispatch/unit based model, where the generating and consumption schedules as well as dispatching of power generating facilities are determined by IPTO within the Integrated Scheduling Process. IPTO ensures that there is sufficient available capacity to provide balancing services for the System and when required issues the appropriate Dispatch Instructions to the Balancing Service Entities.
The Balancing Market consists of three distinct procedures:
1. Balancing Capacity Market:
Each TSO applying a central Dispatching model shall use the ISP for the exchange of balancing services or for the sharing of reserves. The Balancing Capacity Market is executed through the Integrated Scheduling Process (ISP), and aims to commit the Balancing Capacity needed in short term and to achieve a schedule that shall meet the technical constraints of the HETS and the Balancing Service Entities.
The ISP is executed as a Mixed Integer Linear Programming model and is solved as a co-optimization problem taking into account the Balancing Energy and Balancing Capacity Offers of the BSEs as well as their respective constraints, the HETS constraints and the HETS Operator needs, in order to minimize the cost of Balancing Energy and Balancing Capacity procurement. The ISP execution produces:
- the commitment status (synchronization or de-synchronization) of each Balancing Service Entity,
- the awarded upward and downward Balancing Capacity products per Balancing Service Entity for each Dispatch Period of the Dispatch Day, and
- the inter-zonal flows.
IPTO defines the zonal and systemic upward and downward HETS needs per Dispatch Period (30-min) of the Dispatch Day, for the following Balancing Capacity products:
- Upward and downward Frequency Containment Reserve (FCR),
- Upward and downward automatic Frequency Restoration Reserve (aFRR),
- Upward and downward manual Frequency Restoration Reserve (mFRR).
Apart from the above-mentioned Balancing capacity offers, BSPs submit to the ISP upwards/downwards Balancing Energy offers.
For the transitional period before commencement of the coupled operation of the Intra-Day Market of Law 4425/2016, the ISP is executed at three scheduled times for each Dispatch Day D as follows.
|ISP1||It is executed at 16:45 ΕΕΤ on calendar day D-1 and concerns all Dispatch Periods (48 Dispatch Periods) of Dispatch Day D.|
|ISP2||It is executed at 00:00 ΕΕΤ on calendar day D, taking into account the updated input data, and concerns all Dispatch Periods (48 Dispatch Periods) of Dispatch Day D.|
|ISP3||It is executed at 12:00 ΕΕΤ on calendar day D, taking into account the updated input data. The time interval taken into account is from 13:00 ΕΕΤ until the end of Dispatch Day D (24 Dispatch Periods).|
IPTO may execute the ISP at any time for all or for certain Dispatch Periods ("ad-hoc ISP"), in case of an event which significantly affects the scheduling of the Units and the dispatch of the Balancing Capacity. Such events may include but are not limited to significant changes in the zonal Load Forecast, or zonal RES Units Forecast, or the availability of resources, or the HETS conditions.
The analytical timetable of the ISP can be found at the Technical Decision ISP.
BSPs submit Balancing Capacity and Energy offers for Dispatch Day D, from 14:00 to 16:45 ΕΕΤ of the calendar day D-1 per Dispatch Period (30-min). The awarded amount of capacity per Balancing Service Entity is binding and participants are required to have the corresponding capacity available in order to maintain a safe margin for the balancing fo the System in real-time through the aFRR amd mFRR procedures.
2. Balancing Energy Market:
The Balancing Energy Market is the market in which quantities and prices are determined for the activation of Balancing Energy by the respective Balancing Service Providers, in order to balance energy supply and demand, taking into account the Market Schedules and the state of the HETS in real time. The Balancing Energy Market includes the manual FRR process and the automatic FRR process.
In the context of the Balancing Energy Market, the Entities that have the ability to provide balancing services submit bids to the mFRR and aFRR process for the respective energy products, distinctly per direction.
Through the mFRR process IPTO estimates close to real time, based on the System conditions, whether upwards or downwards activation of mFRR energy is required and issues the relevant Dispatch Orders per mFRR Time Unit (15-min), taking into consideration the submitted balancing energy offer prices.
Through the aFRR process IPTO issues in real time automatic Dispatch Orders to the Balancing Service Entities per 4 seconds using the Automaitc Generation Control Function, based on the Balancing Energy Offer prices for automatic FRR and the rate of change of the output capacity of the Balancing Service Entities.
3. Balancing Market Settlement:
Balancing Market Settlement means the transparent calculation of the quantities of Balancing Energy and Balancing Capacity and the calculation of the monetary value of the Participants' debits and credits in the context of the Balancing Market. Moreover, it concerns the calculation of the debits and credits to the Balance Responsible Party for Imbalances for each of the Balance Responsible Entities it represents.
The Balancing Market Settlement is implemented on a weekly basis after the real-time procedures and consists of the following procedures:
- Balancing Energy Settlement
- Balancing Capacity Settlement
- Imbalance Settlement
The Settlement Week W shall be defined as the time period between Monday, at 00:00 CET and the following Monday at 00:00 CET.
Furthermore, in the context of monitoring the smooth operation of the Balancing Market, IPTO imposes the following Non Compliance Charges on Participants, according to Chapter 21 of the Balancing Market Rulebook:
- Consequences of non-timely commitment,
- Consequences of significant deviation from the Registered Characteristics,
- Consequences of non-compliance with manual FRR Test Instructions,
- Consequences of significant deviation from the Dispatch Instructions,
- Consequences of significant systematic demand imbalances,
- Consequences of significant systematic imbalances in the production of RES Units Portfolios, and
- Consequences of systematic failure to attain a feasible Market Schedule.
A detailed description of the timeline and the settlement procedures can be found in the Balancing Market Rulebook, while details and calculation examples of the Balancing Market Settlement are illustrated in the relevant Technical Decision.
The basic principles of the individual Settlement Procedures are presented below:
The Balancing Energy is settled per Imbalance Settlement Period (15-min). The activated energy for each Imbalance Settlement Period shall be calculated separately for the manual FRR, the automatic FRR and for purposes other than balancing.
During the Settlement procedure the activated Balancing Energy Offers per 15-min are taken into consideration according to the following:
- The remuneration of the entities regarding the activation of mFRR Balancing Energy is based on the pay-as-clear principle. Thus, the upward Balancing Energy Price for mFRR for each Imbalance Settlement Period, shall be equal to the maximum of the Balancing Energy Offer prices for the mFRR steps that were activated to cover the HETS Imbalances, while the downward Balancing Energy Price for mFRR shall be equal to the minimum of the Balancing Energy Offer prices for the mFRR steps that were activated to cover the HETS Imbalances.
- The remuneration of the entities regarding the activation of mFRR Energy that will be activated for purposes other than balancing is based on the pay-as-bid principle, taking into account the activated offer steps of the relevant direction.
- The remuneration of the entities regarding the activation of aFRR Balancing Energy is based on the following values:
- For upward direction: the highest value between the price for the upward Balancing Energy for mFRR and the price of the Balancing Energy Offer for aFRR of the Balancing Service Entity corresponding to the quantity of upward Balancing Energy activated for aFRR by the Balancing Service Entity, and
- For downward direction: the lowest value between the price for the downward Balancing Energy for mFRR and the price of the Balancing Energy Offer for aFRR of the Balancing Service Entity corresponding to the quantity of the activated downward Balancing Energy for aFRR by the Balancing Service Entity.
The Balancing Capacity is settled per Imbalance Settlement Period (15-min).
For each Balancing Service Entity and for each Imbalance Settlement Period, the upward and downward Balancing Capacity shall be calculated taking into account the following:
- The segments of the individual steps of the Balancing Capacity Offer that have been validated on the basis of the last ISP execution, whose solution timeframe shall include that specific Imbalance Settlement Period.
- The percentage of a time period within an Imbalance Settlement Period when the Balancing Service Entity was available for the provision of the corresponding balancing capacity product in real time.
The remuneration of a Balancing Service Entity for the Balancing Capacity supplied per product is based on the pay-as-bid principle for the relevant direction, without taking into account whether the entity was actually providing balancing energy during this specific Imbalance Settlement Period.
The 15-minute time period for which the Imbalance of the Contracted Balance Responsible Parties is calculated shall be called the Imbalance Settlement Period.
A single Imbalance Price per Imbalance Settlement Period is used, which is calculated as the weighted average price of the activated Balancing Energy in the predominant direction (upward or downward) for manual and automatic FRR for that Imbalance Settlement Period. The above weighted average price shall be calculated as the quotient of the total amount in € corresponding to the activation of balancing energy in the predominant direction (upward manual and automatic FRR or downward manual and automatic FRR) and the algebraic sum of the activated balancing energy quantities in the predominant direction.
The predominant direction is upward when the activated upward Balancing Energy for manual and automatic FRR for a specific Imbalance Settlement Period is greater than the activated downward Balancing Energy for manual and automatic FRR. Similarly, the predominant direction is downward when the activated downward Balancing Energy for manual and automatic FRR for a specific Imbalance Settlement Period is greater than the activated upward Balancing Energy for manual and automatic FRR.
If neither upward nor downward Balancing Energy was activated for an Imbalance Settlement Period the Imbalance Price shall be equal to the value of the avoided Balancing Energy activation and shall be calculated by finding the mean of the following values:
- the lower upward Balancing Energy Offer price for either manual or automatic FRR for that Imbalance Settlement Period and
- the higher downward Balancing Energy Offer price for either manual or automatic FRR for that Imbalance Settlement Period.