Energy Intensive User Group Generation Maintenance Update L. Reddy Date: 8th May 2012 2018/12/09

Generation Maintenance Index Work execution is tracking planned work closely – ensuring as much that can be done is done Shutdown maintenance parameters remain below par performance and remains an area of concern Lag in planned maintenance reflects lower risk-deferred maintenance Reliability Basis Updates Schedule Compliance Planned Maintenance Compliance 2018/12/09

Shutdown Maintenance: Plan vs Actual (6 month historic view) More than 8000MW on maintenance over Dec-Jan festive period Average capacity on maintenance exceeded 5000 MW for period Actual maintenance approximated 90% of the planned outage requirement Outages scheduled on priority to minimise safety, legal and environmental compliance, to minimise plant damage and then to manage plant reliability – outage scope maximised within available shutdown time; Deferred outages tracked and monitored for continuing risk – prioritisation elevated if risk increases or if capacity allows 2018/12/09

c2012-13 Maintenance Challenge Unoptimised planned maintenance requirement The goal is a maintenance ratio of 10% of capacity, including 3% to address the backlog: Actual achieved at the end of December 2011 is 15.62% and 8.14% for the financial YTD at 16/01/12. The planned outage requirements exceed the capacity available for maintenance and so liquid-fuel open cycle gas turbine usage and demand-side management become critical. Planned outages are ranked on scope and risk, to enable prioritisation of outages within the available capacity. Lower risk outages (inspections and interim repairs) have had to make way for high-risk, high-pressure pipe-work replacements, low-pressure turbine blade inspections and major refurbishment outages. All “deferred” outages are monitored for risk until they can be accommodated.

Shutdown Maintenance Summary Capacity continues to be constrained necessitating optimised scheduling of outages within available capacity allowance Risk-based ranking continues as basis to prioritise outage schedule. Resource constraints becoming an important consideration Increased focus on operational risk reduction – spares availability and turnaround, coal quality outside of contract specification, quality of workmanship during shutdown maintenance Focus on quality of outage planning and execution (“Pit-stop” vision – quality, effective and efficient) Today 8% of generating capacity on shutdown maintenance (incl. Koeberg) For the first time up to two (2) large capacity unit outages will be run through this winter. 2018/12/09