Power System Emergency - 6 March 2014

Transcription

1 Power System Emergency - 6 March 2014 Brian Dames Chief Executive 7 March 2014

2 Key Message Overview of the Power Emergency Declaration System Status Understanding load shedding Conclusion 2

3 Key Message Overview of the Power Emergency System Status Understanding load shedding Conclusion 3

4 Key messages Eskom declared an emergency at 06:00 on 6 March 2014 and for the first time since 2008, implemented rotational load shedding at 08:00. The emergency was lifted at 22:00 on 6 March 2014 and load shedding stopped This was a painful yet necessary decision to protect the electricity power system from a total black-out. A total black-out would have significant consequences on the South African economy Eskom s power stations are old and the system is tight. Any event impacting >1500MW, could have a significant impact on the availability of supply While we are committed to provide early warning, this was the earliest we could communicate as the system status changed rapidly in the early hours of the morning of 6 March 2014 Eskom is in a better position than in 2008 to manage the situation. - experience and knowledge of managing this complexity, appropriate emergency and communication protocols in place and open and transparent communication with stakeholders, including the media The system will remain tight up to the end of Summer and throughout Winter, until a substantial part of the build programme delivers capacity It remains important for all customers to maintain or achieve 10% electricity savings especially in the commercial, 4industrial and residential sectors.

5 2008 vs load shedding Communication of system status Executive management oversight (pre-incident) Country demand reduction protocols Load shedding (small customers) Load curtailment (large customers) Inadequate pre-communication of system constraints Inadequate integration between functions prior to the incident No country protocol in place Schedules developed during the critical constraint No pre-agreement -Pro-active communication (Quarterly system updates, summer/winter comm s) - Improved communication with customers, media and other stakeholders Executive team assigned, Emergency command centre (ERCC) established, weekly reviews, alignment with shareholder National Code of Practice, based on multistakeholder input, approved by NERSA Prepared and published by Eskom and Metros before the emergency as per Code. Signed curtailment agreements Preparedness Limited exercises and tests. Regular operational and two national multi-stakeholder exercises. Visibility Declaration of an emergency Limited visibility of key processes Once system was nearing instability. Detailed information via Generation and Customer Nerve Centres & National Control Help Desk In line with the National Code of Practice. Coal supplies Unhealthy levels on average Healthy levels on average at 45 days 5

6 As a reminder - electricity usage in Summer and Winter Sept-March Spring/Summer Live Lightly April-Aug Autumn/Winter Beat the Peak Table Mountain profile Constrained all day incl. from 5-9pm Air-conditioning, geysers & pool pumps primarily impact demand Commercial, agricultural & residential customers can make the biggest difference Peak profile Constrained from 5pm 9pm Electrical heating, geysers, & pool pumps primarily impact demand Residential customers can make the biggest difference as demand increases in the evenings 38,000 MW Summer & Winter load profiles 36,000 34,000 32,000 30,000 28,000 26,000 24,000 Summer flat (Table Mountain profile) 22,000 Typical Winter Day 20,000 23:00 02:00 05:00 08:00 11: :00 17:00 20:00 23:00 02:00 Winter Peak Profile

7 Key Message Overview of the Power Emergency System Status Understanding load shedding Conclusion 7

8 Overview of events leading up to the emergency The already constrained power system was further impacted by the following events: - The continuous rain in the last few days resulted in poor coal quality resulting in additional load losses at our power stations - A rapid change on the system in the early hours of 6 March 2014, as we lost additional units at our power stations (4 x Kendal, 1 x Majuba, 1 x Grootvlei MW lost by 05:00). - There was limited available generation at Drakensberg and Palmiet - Eskom utilised all emergency reserves at its disposal: - Open-cycle gas turbines were brought on-line - Demand market participation (DMP) including Emergency from key industrial customers were utilised Over and above the utilisation of emergency reserves there was a shortage of 3000 MW at 08:00. To manage the frequency levels and to protect the national system from total collapse, controlled load shedding was implemented immediately and unavoidably at short notice. The stage 3 load shedding resulted in a 20% reduction in demand enabling National Control to balance the system 8

9 Cross-border impact during an emergency During Eskom system emergencies the following applies to exports: All non-firm energy supplies are reduced to zero, All firm energy supplies are reduced by 10%, Trading Partners are required to enforce the 10% reduction on their customer base, Trading Partners are required to utilize all their own generation capacity to the maximum, Energy which may inadvertently be drawn out of the Eskom system is charged at emergency generation rates, The interruptibility of the specific customer agreements is activated by National Control as the system requires it. 9

10 Generation challenges Generally Eskom s power stations are old and are impacted by frequent break downs. Increased boiler tube leaks are the primary reason behind generator outages. Outage slips and extensions have taken much longer than initially planned due to the state of the plant when opened up for inspection as well as some performance issues in execution. Over this week, some power stations in the Mpumalanga area were further challenged due to the high, continuous rainfall over the past eight days that impacted coal quality (wet coal). This severely impacted their ability to effectively handle and feed coal to the boilers at the power stations Coal stockyard under water Conveyor belt impacted by wet coal The result is that key power stations in the area are operating at additional reduced outputs 10

11 Wet vs. dry coal stockyard Wet stockyard Dry stockyard 11

12 Wet vs. dry coal on conveyors Wet Dry Wet 12

13 Kendal sequence of events (1) 1 2 Experienced problems handling wet fine coal. Took load losses up to 400 MW from 21:00 Coal stock level above target at 56 days. Have experienced consistent heavy rain since Friday last week Wednesday 3 During shift change-over fine and wet coal received from opencast mine with low delivery of dry coal from underground mine. Supplemented shortfall with fine and wet coal from stockpile. This makes handling of coal on conveying plant difficult - causing blockages and incline conveyor belts slipping Wet fine coal

14 2. Coal Handling Plant Overview

15 Kendal sequence of events (2) Thursday By 17:26 all units at Kendal back on load 6 5 Units were recovered during the day by getting dryer, coarser underground coal Trips due to empty coal bunkers during early hours of Thursday Unit six 01:22 Unit one 01:40 Unit two 02:26 Unit five 07:

16 Kendal coal stock yard Coal stock yard 1.3 km x 800 m 16

17 Wet coal management initiatives since 2008 Infrastructure Process Measurement and Control Guided flow chutes at Duvha By having a robust supply Staithe plan bypass for all our conveyors primary energy resources, able to face and recover from: Adequate coal stockpile holding 5 day coarse coal stockpile at critical stations Wet coal management procedures per station Annual rain season readiness audit for power stations External rain season audit of mines Review of management and operating procedures Initiatives investigated but not implemented due to cost constraints Re-claimers Covered stockpiles Additives

18 Duvha Power Station Coal Supply Constraints Conveyor fire incident in December 2013 resulted in total supply to Duvha being sourced via road transport Middelburg Mining Services (MMS) constrained to supply full volume due to infrastructure and process flow Additional volumes available from MMS North Plant, however road construction and associated safety risk makes supply infeasible Additional coal supply sourced from various short term sources Feed to station constrained by current weather conditions Weather conditions impacting on return to service of conveyor system Supply in the latter part of March 2014

19 Stock days Coal stocks at sufficient levels Current coal stock piles are at healthy levels, in average of 45 days. Power stations that are highly dependent on road deliveries like Grootvlei, Komati and Tutuka stock days have dropped below alarm level in February mainly due to mine and road deliveries slow ramp up after the festive period, social unrest around specific routes and rain. Duvha Power Station stock days dropped due to the conveyor fire, but are being maintained around 14 days In anticipation of long duration rainfall, strategic stockpiles are set aside for such situations. However, given the duration of this rainfall period these strategic stockpiles have been depleted. Actual Stock days F2008, F2012, F2013 vs YTD Actual F /8 2011/ / / Months APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR 19

20 Open cycle gas turbines Costly liquid fuelled gas turbines in the Western Cape continue to be used during the day, as an emergency resource, to meet the required demand Very expensive We are currently managing the utilisation of these units to safeguard fuel levels Ankerlig 20 Gourikwa

21 Key Message Overview of the Power Emergency System Status Understanding load shedding Conclusion 21

22 February 2014 compared to February February 2013, February 2014 (Monday Tuesday) 2014 Difference 2013 There is an average difference between 1000 MW and 2200 MW over peak periods IPP supply expired Dec

23 Available capacity to meet demand 4 Kendal units lost Emergency declared Emergency declared The emergency of 20 and 21 February 2014 was particularly tight from the Thursday afternoon and into the Friday afternoon. A substantial change can be seen on the emergency of the 6 th March when the available capacity was much lower than the entire day s demand 23

24 Prognosis for the next two weeks Rainy weather conditions are forecast until the beginning of next week Any small change on the system could have a significant impact: risks include fuel shortages, increased plant maintenance This plan considers a forced outage allowance of 6500 MW. This does not cater for significant events such as those experienced this week which will result in much tighter operations and reliance on emergency reserves. 24

25 Prognosis for the next two months The risk of emergency conditions developing remains with us for the rest of March and into April. From a planning perspective, the unplanned outages are expected to reduce as we go into winter. Planning is consistently in the red which makes us extremely vulnerable to any unforeseen events. Koeberg unit 2 is scheduled to come out of service for planned maintenance in the third week of March. Decision on license agreements on Kriel PS expected in the latter part of March

26 Supply-side: Renewable IPPs gain momentum The Department of Energy introduced three bid windows for the Renewable Independent Power Purchase Programme Of the 19 Renewable IPPs connected to the grid, 3 projects (99 MW) have achieved their contractual Commercial Operation Date (COD) and 8 projects are generating Early Operating Energy. Expect the last project of Bid Window 1 by no later than the first half of 2015 Bid Date MW Power Purchase Agreements Type of Technology Status (As at 21 February 2014) 1 5 Nov Wind, Solar PV, Solar CSP 2 9 May Wind, Solar PV, Solar CSP, Landfill & Biomass - 19 of 28 connected - 3 projects achieved COD; 8 projects in Early Operating - Last plant commercial expected by Feb Progressing well 3 - Bid Window 3 still to be concluded 17 bidders for 1456 MW - Wind, Solar PV, Solar CSP, Landfill and Biomass technology 26

27 Supply-side: Cross-border IPPs Only until recently was Eskom allowed to conclude power purchase agreements with regional independent power producers While Eskom is committed to use IPPs, most contracts could not be concluded due to high price expectation Project Type Potential Eskom off-take Kudu Natural gas 27 Status 800 MW 600 MW Eskom spent substantial time negotiating. PPA could not be concluded due to price Mmamabula Coal MW 900 MW IG MOU signed Due to high price expectation could not be signed Explicit linkage to coal price which was higher than the Eskom coal cost New regulations implemented in RSA making the DoE the procurer Zesco Coal and Hydro 200 MW 200 MW Could not be concluded due to high price expectation Kariba South Hydro 120 MW 50 MW Could not be concluded due to high price expectation

28 Continued progress with New Build Eskom is committed to completing the new build programme and has put the necessary resources in place to do so Work has resumed at Ingula pumpedstorage scheme after the safety incident Medupi and Kusile continue to demonstrate world-class safety performance (0.1 lost time incident rate). Medupi s first unit is still expected to be synchronised in the second half of 2014 and Kusile s first unit following a year thereafter. The technical C&I issues at both Kusile and Medupi are being addressed with the on-boarding of Siemens. 28

29 Continued Progress with New Build Seven of the 46 wind-turbines at Sere PS are complete and the station s 100MW is expected to be commissioned by 2014/2015 Transmission power line construction is progressing well, major sections of the power grid (Western Cape, Limpopo and Gauteng) have been strengthened, although challenges still remain in terms of servitude acquisition. 29

30 Key Message Overview of the Power Emergency System Status Understanding load shedding Conclusion 30

31 Balancing supply & demand Electricity demand must be matched in real time. Any mismatch in supply and demand is reflected in the system frequency. Strict frequency control is required in order to ensure system security. This requires 24/7/365 management of the integrated power system. This is a primary role of the System Operator (National Control) 49.5 Hz 50.0 Hz 51.5 Hz Generation Load 31

32 Declaring a power emergency NRS048 On days when Eskom needs to reduce demand still further, after utilising emergency reserves, the NRS048 protocol indicates that Eskom can declare a power emergency in order to protect the system from a total blackout or collapse It does this by instructing key industrial customers to reduce load by 10%. When all options have been exhausted, and if the demand still exceeds available supply, Eskom initiates rotational load shedding. This is a scheduled process and is a controlled way of sharing the available electricity between all customers. By switching off parts of the network in a planned and controlled manner throughout the day, the system remains stable, and the impact is spread over a wider base of customers. 32

33 Emergency demand reduction Demand reduction is executed in Stages. Each stage provides a given amount of demand depending on the season and time of day. The System Operator (National Control) determines the capacity shortfall and instructs the relevant stage of shedding to Eskom s Top Customer division and Eskom s Distribution control rooms. These control rooms in turn instruct the metros and municipalities to prepare for and implement load shedding. Procedures are in place to engage critical loads as defined in the Code of Practice (e.g. hospitals, airports, stadiums etc). These cannot all be kept off the schedules and therefore the necessity that these services keep back-up generators 33

34 Load shedding protocols Unlike 2008, where Eskom implemented load shedding through-out the day and for a few days at a time, load shedding will now be used only under emergency conditions for limited periods. For Eskom customers only, four schedules have been developed based on the possibility of risk and to ensure that it is applied in a fair and equitable manner: An All Day Schedule (24 hour) Applicable during Summer and Emergencies (any time of the year) Three schedules for Peak Stages during (5pm to 9pm) Applicable during Winter. Eskom schedules cater for Eskom supply areas only Customers supplied by municipalities need to contact their municipalities directly. Municipal load shedding is managed independently 34

35 system emergency National Code of Practice (NRS 048-9) Demand reduction under system critical constraints & emergencies Mandatory demand reduction shedding vs. curtailment Stage Type Reduction obtained by interrupting supply - load shedding Stage MW Unscheduled (pre-agreed) Ad hoc Reduction obtained by instructing reduction - curtailment (pre-agreed) Load offered by customers under the immediate curtailment option (min 25% for 2 hrs) Stage MW Scheduled / Notified Shed 5% of national noncurtailment load at peak Curtail 10% of normal demand within 2h of notification Stage MW Scheduled / Notified Shed 10% of national noncurtailment load at peak Stage MW Scheduled / Notified Shed 20% of national noncurtailment load at peak Curtail 20% of normal demand within 2hrs of notification Stage 4 Unscheduled (instructed) Shed >20% of national noncurtailment load at peak As instructed by the National System Operator at the time. 35

36 Stage 1 ALL DAY Schedule: Eskom customers only Monday Tuesday Wednesday Thursday Friday Saturday 06:00 Block 9 Block 1 Block 9 Block 1 Block 9 Block 1 08:00 Block 10 Block 2 Block 10 Block 2 Block 10 Block 2 10:00 Block 11 Block 3 Block 11 Block 3 Block 11 Block 3 12:00 Block 11 Block 4 Block 11 Block 4 Block 11 Block 4 14:00 Block 13 Block 5 Block 13 Block 5 Block 13 Block 5 16:00 Block 14 Block 6 Block 14 Block 6 Block 14 Block 6 The current schedule is designed to be fair if load shedding takes place during most of the day. 18:00 Block 15 Block 7 Block 15 Block 7 Block 15 Block 7 20:00 Block 16 Block 8 Block 16 Block 8 Block 16 Block 8 36

37 Where to locate the load shedding schedules: Option 3 Internet Add slides 37

38 Where to locate the load shedding schedules Option 3 Internet Add slides 38

39 Key Message Overview of the Power Emergency System Status Understanding load shedding Conclusion 39

40 Help us to communicate better While the load shedding schedules for Eskom customers were loaded, the system failed to perform optimally. Complaints were received around the accessibility of the site in particular Our customer contact centres were inundated and due to the overload were unable to help all customers We saw significant uptake on social media and we trended on twitter. We recorded a significant increase in social media shares of messaging across all platforms (130 million compared to daily trend of 1 million) The media houses reacted positively and we continue to have spokespeople across the country on various broadcasters to respond to media requests We welcome suggestions and feedback from the public on ways to improve the load shedding schedules. Please contact us on central@eskom.co.za or

41 How to Live Lightly and Beat the Peak Saving electricity reduces pressure on the grid and cuts your electricity bill and South Africa s carbon emissions The power system remains vulnerable all day during Summer 1. Use air-conditioning efficiently - Set air-conditioning at 23 degrees - Close windows and doors to optimize air-conditioning - Switch off 30 minutes before leaving the office 2. Continue to switch off all geysers and pool pumps from 5pm to 9pm 3. As we approach winter, use alternatives to electrical heating 4. Switch off all non-essential lighting and appliances 5. Respond to the Power Alert and Power Bulletin radio messages by switching off all appliances that are not being used 41

42 Conclusion The system remains tight and is vulnerable to any changes going into Winter, and will remain so for the next few years until the build programme is completed With the projected demand and current trends in plant performance, extensive and expensive use of OCGTs is anticipated, resulting in limited operating reserves to deal with volatility in demand or generation performance. We call on all customers, particularly the municipalities and the commercial sectors, to manage and cut out all electricity wastage. The industrial and commercial sector can make significant contributions particularly in large office blocks and shopping centres. If this is done, it will ensure a stable power system and reduced costs We thank all our customers who continue to assist by reducing consumption. In support of

43 Thank you