1. Simulator for the Hellenic Wholesale Electricity Market
K. Sakellaris, A. Vlachos, K.Perrakis
Regulatory Authority for Energy (RAE), Athens, Greece
Michael C. Caramanis
RAE & Boston University, USA
Sidart Deb
LCG Consulting, USA
Presented by: Kostis Perrakis
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

2. The Hellenic Electricity Market
Market structure: PPC, the national integrated utility still retains very high market shares
Wholesale: 95% of capacity, 96.2% of energy
Retail: ~ 100% (99.99%)
Wholesale Market model: mandatory pool
All generators and suppliers / consumers within the country have to transact within the Day-Ahead market organized by HTSO (the Hellenic System Transmission Operator)
No bilateral transactions with physical delivery
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

3. the Hellenic Wholesale Electricity Market
( Law 3426/2005 and 2005 Market Code )
Day Ahead market (mandatory pool, 24 hrs horizon)
main volume of electricity trading
Reserves
Real-Time Dispatch (5 min. Economic Dispatch)
Imbalances Settlement
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

4. Security Constrained Day Ahead Schedule
On the Day
After the Day
Real time dispatch
Dispatch Instructions and Adjustments of Day Ahead Schedule
Energy and reserves schedule, satisfying System and Generating Units constraints
Dispatch Instructions and Forced Production Changes
Imbalances
Settlement
Calculation of Imbalances between Measured and Scheduled Production (not including Forced Production Changes).
Settlement at the Imbalances Marginal Price.
Additional payments for Forced Production Changes.
Measurement Data
Security Constrained Day Ahead Schedule
Imbalance payments and charges.
Charges for reserves and ancillary services used.
Payments for reserves and ancillary services provided
Declarations of Load and Exports (may be priced)
Day Ahead P Q
SMP
System Marginal Price (single for Suppliers, zonal for Generators), Primary and Secondary Reserve Prices
Energy and
Reserve Offers,
Techno-Economic Declarations, Non-Availability Declarations
Importers
Hydro and Renewables
Producers
Payments
Charges
Suppliers
Exporters
Pumping Units
HTSO
Transmission System constrains, Reserves needs, Market Split rules
DAS Settlement of Accounts for Energy
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

5. PROMETHEAS -2 CONFERENCE, 9-10 OCTOBER 2008
Simulator Overview
several modules (simulating modules and auxiliary modules)
Load Flow (LF) of the Greek transmission system
Day-Ahead Market (DAEMC)
Economic Dispatch (ED) – 5 min.
Financial Settlement of Differences (FSoD)
Natural Gas Transportation System (NGTS)
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

6. PROMETHEAS -2 CONFERENCE, 9-10 OCTOBER 2008
Simulator Overview
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

7. PROMETHEAS -2 CONFERENCE, 9-10 OCTOBER 2008
Simulator Overview
Common methodologies and techniques, related to power systems operation and optimization
Special modelling and simulating functionalities integrated in the system in the sense of providing even more realism to the operations simulated.
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

8. PROMETHEAS -2 CONFERENCE, 9-10 OCTOBER 2008
DAEMC (1)
simulates the Day-Ahead market algorithm
determines quantities and prices (optimal schedule & uniform equilibrium prices) maximizing social welfare for the 24 hourly periods of the next day simultaneously.
Practically, a Unit Commitment (UC) solver, as it performs an optimization, using Mixed Integer Programming (MIP).
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

9. Solving the DAEMC: hourly equilibrium
MWh
€/MWh
Load
Surfaces left of the load curve correspond to Load Declarations that are being served
Load Declarations without price component
System Marginal Price (SMP)
RES, Mandatory Hydro Operations
Surfaces under the equilibrium price are collected by the Producers
The credits and debits are settled at the System Marginal Price
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

10. PROMETHEAS -2 CONFERENCE, 9-10 OCTOBER 2008
DAEMC (2)
Objective function
Cost of energy injected
‘Value’ of energy consumed
Cost of primary, secondary and tertiary reserve
Cost of unit de-commitment
(costs and values based on participants’ offers and bids)
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

11. PROMETHEAS -2 CONFERENCE, 9-10 OCTOBER 2008
DAEMC (3)
Constraints:
Energy Balance: Energy balance for each zone, Priced Demand Constraint
A/S Requirements: Primary, Secondary, Tertiary Reserve Constraints
Unit Constraints: Upper bound of capacity block, Maximum available production, Technical minimum, Combined energy and reserve margins contribution, Primary, Secondary, and Tertiary Spinning Reserve Capability, Ramp Up/Down, Minimum Up / Down time
Zone/Zonal Energy Flow: Imported and Exported energy limit at interconnection nodes, Upper limit of energy flow between Zones
Initial Conditions
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

12. PROMETHEAS -2 CONFERENCE, 9-10 OCTOBER 2008
DAEMC (4)
Infeasibilities
Slack variables are used for all constraints which could potentially render the problem infeasible
prioritization of respective cost coefficients (´penalty factors´), eg.:
100,000 Euro/ MWh for energy deficit
20,000 Euro/ MWh for secondary reserve deficit
10,000 Euro/ MWh for tertiary reserve deficit
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

13. Economic Dispatch (ED)
Dispatches already committed units every 5 min (DC-OPF)
Based on Day-Ahead offers and bids
Unplanned variability (generators, load, renewables) taken into account
Look-ahead capability: e.g. 13 periods (of 5 min. each), to account for generators ramping up/down
Recommitment (to simulate decisions taken in real time whenever a significant event takes place)
Uninstructed deviations: capture the effects when generators do not follow instructions and dispatch orders
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

14. PROMETHEAS -2 CONFERENCE, 9-10 OCTOBER 2008
Volatility Module
simulates unplanned variability
Generates “real life” events:
a. Random and Unforeseen Events, modeled using Monte Carlo Simulations, regarding
Generator Availability
Changes in Demand
Changes in the Renewables Output
b. Deliberate actions by market participant (e.g. not following a dispatch order), specified by user input.
Follows predefined or customized probability distributions, and patterns of specific strategic participant behavior.
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

15. Financial Settlement of Differences (FSoD)
Input: the results of the DAEMC and the ED
Output:
the deviations of the ED from the DAEMC (for all ´products´, i.e. energy & reserves)
the financial settlement (credit / debit) resulting from these deviations
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

16. PROMETHEAS -2 CONFERENCE, 9-10 OCTOBER 2008
NGTS Module
simulates the operation of the Hellenic Natural Gas Transportation System (NGTS)
Checks the ability of the NGTS to accommodate the expected operation of the gas-fired plants, on the basis of the output of the DAEMC and ED Modules (taking also into account the needs of the rest of the natural gas consumers in Greece)
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

17. Modules integration and s/w development: (1) core software
All modules, apart from the NTGS simulation engine, were originally programmed and integrated under a common user interface. The main programming language used is .Net®.
The NTGS module uses externally commercially available software, PipeLine Studio®.
The DAEMC and ED modules utilize the core optimization engine of CPLEX®.
The LF module uses the commercially available UPLAN® software as its core.
The ED module was essentially written from ground up, but contains some proprietary algorithms which were taken from the UPLAN® system.
The Volatility and FSoD modules were created uniquely for the simulator.
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

18. Modules integration and s/w development: (2) user interface
Rich collection of panes and tabs that provide quick and easy access to input data, configuration and execution parameters, and results.
Traditional powerful searching and filtering techniques that facilitate viewing and editing relevant input data.
Built-in charting capability for time series data graphical representation.
All features Integrated in simulator providing a streamlined, user-friendly, and very effective user Interface.
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

19. Modules integration and s/w development: (3) user interface
Software architecture is such that allows for maximum configurability providing a versatile simulation environment
The user can edit and change every input data and parameter, which makes it possible to construct any simulation scenario.
Two very powerful features, enhancing flexibility:
Generic constraints in DAEMC (users can introduce constraints affecting the energy or ancillary service contribution of certain units or groups of units)
Rule addition & editing in the FSoD module
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

20. PROMETHEAS -2 CONFERENCE, 9-10 OCTOBER 2008
Next Steps
actual use of the Simulator in order to:
study instances of the market and strategies used by participants for market manipulation and monopolistic / oligopolistic gaming
in the energy as well as ancillary services markets
assess the effectiveness of current market rules as well as contemplated regulatory policy and market rule redesign
development of a mathematical model capable of predicting plausible bidding strategies of market players that are compatible with the market rules in place and different objective conditions that may prevail.
PROMETHEAS -2 CONFERENCE, OCTOBER 2008

21. Thank you! REGULATORY AUTHORITY FOR ENERGY (RAE) Kostis Perrakis
Systems Analysis Department
PROMETHEAS -2 CONFERENCE, OCTOBER 2008