Overview of System Operator (National Control ) Short term Supply/Demand

Transcription

1 Overview of System Operator (National Control ) Short term Supply/Demand

2 Who Participates in the EPP Gx Gx GPS Dx Dx EMD Cluster 1 Cluster n Regions Power Station 1 Power Station n Eskom Tx Eskom Power Pool Power Exchange & System Operator Contracts/Tariffs Special Deals RTP Cust s KSACS Cahora Bassa SAPP

3 Market Governance (MMM) DME sets Guiding principles NER Veto right Market Code Veto right System Operator IRP RP GCRP Grid Code MSP approves budget MGB supports Market Operator MSU supports MMM Governance Framework: Final Report, 2003

4 Eskom Power Pool Governance Eskom EXCO (Ops) Pool Governance Committee 2 per Division + Chair + 2 Officials Pool Rule Subcommittee Advisory Committees Advisory hoc Committees (advisory) committees Ad hoc committees

5 Trading platforms Financial Contracts (Hedging) Forwards / CFDs (Bilateral/OTC) Futures (Exchange) Options (Bilateral/ OTC/Exchange) Other (Bilateral/ OTC/Exchange) Sellers Physical Contracts (Energy and Ancillaries) Forwards (Bilateral/OTC) Day ahead (Exchange) Buyers Capacity Market (Bilateral/OTC) Balancing - Hours ahead to real-time (Exchange) Real Time Operation Real-time Implementation of Energy and Ancillary Contracts

6 Supply Demand

7 Power Suppliers Different fuels Nuclear Fossils Hydro/ Pumped Storage Gas To produce the same commodity: Electricity

8 Eskom s Power Pools Two pools side by side SAPP Eskom Pool

9 Trading platforms Decades/ Years/ Day Hour Minutes Seconds Cycles Years Months < Invest Fuel Contracts Marginal Availability Costs DA BM Physical bilateral STBT Financial markets Build Operate Maintain Schedule Operate Unit Commitment Economic Dispatch Ancillaries

10 EPP - Schematic of the daily process LOAD FORECAST UNCONSTRAINED SCHEDULE GENERATOR BIDS GENERATOR CONSTRAINTS SYSTEM CONSTRAINTS DAY AHEAD CONSTRAINED SCHEDULE POOL PRICES GENERATOR CONTRACTS SYSTEM DYNAMICS GENERATOR DISPATCH REAL TIME

11 Generator Offer (for each unit) R/MWh Self-commitment / decommitment or based on price (each hour) Price curve (for a day) Availability, flexibility and technical parameters INC3 INC INC2 INC1 INC0 ELBOW2 EMGEN MINGEN ELBOW1 MAXGEN MW

12 Supply / Demand Curves and SMP R/MWh D S MW

13 Short Term Supply/Demand Balance

14 Overview At the beginning of 2009, a substantial reduction in demand was experienced due to the economic recession. When doing a year on year comparison on the energy sent out, the total reduction has been reducing every week. The year on year reduction for 2009 vs 2008 was approximately 2%. Load seen to date this year is similar to that of 2007, which was Eskom s highest peak ever (9% increase in 2010 compared to 2009) 2010 is going to be tight, but with normal generation performance, we are unlikely to result in a severe imbalance. A number of initiatives are being implemented around the World Cup period (11 th June 11 th July) to increase the resilience of the power system to higher than planned for failures.

15 Weekly energy sent out Weekly Energy Sent Out % % % GWh % 7.50% 7.00% 6.50% Cumulative Y-Y growth % % % Week Number An approximately 2% energy reduction was seen for 2009 vs 2008 Year to date, there has been about 9% growth compared to 2009

16 Weekly peak demand Weekly Peak Demand MW Week Number The peak for 2009 was around MW The current forecasted peak for 2010 is MW. Current Demand is showing 7% growth compared to 2009(W-W)

17 /01/25 Indicative supply/demand balance (Analysis at 25 Jan Including OCGTs) 2010/02/ /02/ /03/ /03/22 Planned Maintenance: 2010/04/ /04/ /05/ /05/ /05/ /06/ /06/ /07/ /07/ /08/ /08/23 The current load forecast assumes some further recovery of the economy. However, it is constantly reviewed, and particularly after the first few weeks of normal economic activity better predictions can be made. Including all emergency generation, there is adequate capacity for demand and normal reserve allocations. In planning mode, 1300 MW of OCGT is considered. There is a marginal shortfall on reserves for almost the entire year, with the exception of the World Cup period. 2010/09/ /09/ /10/ /10/18 Reserves Weekly Maximum Demand 1300 MW OCGT Available Capacity Installed Capacity 2010/11/ /11/ /11/ /12/ /12/27

18 Comments The normal average allowance for forced outages is 2500 MW. On many occasions over the last month the actual forced outage rate has been higher than this not unusual for this time of the year Some of it has been weather (rain) related, particularly related to coal handling at specific power stations The month ahead picture is likely to be relatively similar to this month. There is a daily focus on the balance between planned maintenance requirements and system tightness Interruptible loads Only used one day in January OCGT Only used one day in January System is tight Making use of EL1 and VPS more frequently Similar state is expected to exist between now and winter 2010.

19 Overview of Eskom s System Operator (National Control )

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21 Sunset Regulator South African Government (Minster of Public Enterprises) (Ms Barbara Hogan) Eskom Holdings System Operations & Planning Enterprises Generation Transmission Distribution HR Regulated Businesses Finance System Operations & Planning Division Corporate Services Energy Planning Grid Planning Research & Innovation System Operator TOC & 6 Regions Growth Management Business Strategy & Planning

22 Energy Management Responsibility Production 45% of African Power Generation 95% of South African consumption 1500 MW +/- from Cahorra Bassa 1800 MW Interruptible load 1900 MW Possible SAPP imports GWh sold to neighbours Coal stockpile : 42 days Peak Demand MW - 27 July MW - 14 July MW - 4 July MW - 29 June MW - 22 June MW - 13 July 2004

23 SAPP Peak Demand 2007 Southern African Power Pool No Country Utility Demand (MW) Angola Botswana DRC Lesotho Malawi Mozambique Namibia South Africa Swaziland Tanzania Zambia Zimbabwe ENE BPC SNEL LEC ESCOM EDM NamPower Eskom SEB TANESCO ZESCO ZESA , , ,468 1,758 Durban Munic Ethekwini 1,900 TOTAL SAPP 43,857

24 Seasonal Load profile comparison Winter Summer Mon Mon Mon Tue Tue Tue Wed Wed Thu Thu Thu Fri Fri Fri Sat Sat Sun Sun Sun Outages are planned considering the peak demand Summer load profile is a lot flatter than winter profile In Winter there is a higher probability of problems over the peak period. Peaking plant is required in winter for many more hours in a day than in summer

25 27.1 Context Declining reserve margin Net Reserve Margin (%) % aspiratio n Emergency Level 1 = 300 MW Demand Market Participation = 180 MW Peaking Gas Turbines : (Port Rex, Ankerlig & Gourikwa) = 2400 MW Interruptible Load = 2000 MW Planned Load Shedding = None Peak demand

26 Load shedding mechanism used to manage the system under any scenario Usage depends on load profile Operating Reserves EL1 VPS ILS > 1900MW MW Demand MW Demand MW Demand - > 1100 MW OCG T M L S Operating Reserve should be 1900 MW Additionally: EL1 Emergency Generation Level 1 - Extra Generation VPS Virtual Power Station Demand Market Participation - Load Reduction - No long term contract ILS Interruptible Load Shedding - Load Reduction - Long term contacts (2000 MWs) OCGT Open Cycle Gas Turbines - Extra Generation (2400 MWs) MLS Manual Load Shedding - Load Reduction Highly unlikely that the resource will be used Partial usage of the resource, probably over peak periods Extensive use of resource (over most of the day) Maintain operational control during incidents and provide buffer to manage frequency

27 Grid Security Responsibility Windhoek Namibia Problems : Voltage constraints Thermal constraints Export/import Botswana constraints T H Zimbabwe H H Gaborone ET Pretoria Johannesburg South Africa ET ETET ET ET ET ET ET ET ET ET H T Maputo Mbabane Swazilan d T H H P Lesotho MWs Cape Town N P 400 kv ( km) 275 kv (7 390 km) 220 kv (1 333 km) 533 kv (1035 km) Total = +/ km) 765 kv (1 153 km)

28 What is the System Operator? Namibia Zimbabwe Botswana The System Operator is the electricity T H Windhoek ET transport and distribution Gaborone supervisor. H H T Pretoria Johannesburg South Africa Task 24 hours a day Transmission transports the electricity to Distribution H P Lesotho ET ET ETET ET ET ET ET ET ET ET H T Maputo Mbabane Swaziland Generation makes the electricity. Generation H Load Distribution then sells the electricity to the customer Cape Town N Balance Load against Generation P System Operator ensures delivery and quality

29 National Control Responsibility Eskom Network N C := kv Network and Detailed Operating Servic Regions Regional Controls := kV Substations

30 Morning Report Executive Summary Frontpage Generation Plant Status Executive Summary Report Estimated Generation Reserves Day-Ahead Reserves for the Peak Hour Day-ahead contracted reserves Generation Plant Outage Schedule Chronological Incident Report Transmission Plant Outage Schedule Pump Storage Schedule - Drakensberg Pump Storage Schedule - Palmiet Sentout Load

31 Voltage Page Summary

32 Control Room Responsibility Satellite image of northeastern US and Canada taken before blackout on Aug. 13, 2003, at 9:21 p.m. EDT. Satellite image during blackout taken on Aug. 14, 2003, at 9:03 p.m. EDT Balanced supply and demand (minute by minute) Quality voltage profiles (both at supply points and on the grid) Managed real-time technical risk (for planned and unplanned events) Restoration (if there is an interruption) Provision of real-time information Affect - 10 million people in Canada (one-third of Canada) 40 million people in 8 states (one-seventh of the U.S.). Estimated financial losses $4 - $6 billion.

33 The Control Control Room Room Items to note in the control room: Frequency Indications Two Time indications Area Control error (ACE) Total Instantaneous Load There are 8 control Desks Head of Shift Voltage Control Loading Transmission 1 Transmission 2 Plant Condition Monitoring Commissioning. PAS