Transmission Ten-Year Development Plan 2011-2020 - Eskom

Type Total R’mil
Customer 6,100
Generation 31,200
Reliability 127,000
Grand Total 164,300
Table 7.2: Capital expenditure per project type
Please note that the amounts in the tables represents cash flows in the Ten-year plan periods, any cash flows not falling
within this period have not been added, consequently the total cost of the plan may be higher than reflected here. The total
excludes Scope Definition Costs.
The details of costing per Grid and Project type are shown in Appendix B. For purposes of confidentiality the planned
or exact costs per project of Customer Projects have been excluded from the table, however the total sum of all
customer projects are indicated in Table 7.2 above.
8. Concluding Remarks
The most visible difference between this TDP and the previous year’s TDP is the phasing and spread of the projects
over the planning period. There has been some re-phasing of the existing projects, using more realistic completion
dates based on execution timelines, as well as to address financial constraints resulting from the current shortage of
capital.
There have been a number of additional projects included in the middle part of the planning period mainly due to new
substation injection points and existing substation transformer expansion. This is mainly due to a better positioning of
loads due to spatial load forecasting techniques applied.
There has been a reduction in the transformation capacity requirements ( by 4) over the new TDP period compared
to the previous TDP which is mainly due to an increase in the number of transformers expected to be commissioned
in the year 2010 (by 8) which is outside of the new TDP window.
The total kilometres of additional lines has reduced from the previous TDP (by approx a total of 1100km) mainly due
to lines commissioned in 2010 (approx 550km) and the re-phasing of existing projects beyond the 2020.
The resultant is an improved and more realistic or achievable spread of the transmission line projects and transformer
installations. The result of the slower rate of completion of the transmission lines and new transformers is the
increase of the risk to the network overall. This can be seen by the number of N-1 unfirm substations which take a
longer period to be resolved as opposed to the previous TDP. However this risk can be managed as the N-1 unfirm
refers to the strict deterministic level which assumes that the N-1 event will happen at the time of the loading peak.
In reality there is a limited chance of this happening and operational mitigation plans will cater for most of the events
until the required projects are completed.
© Eskom 2011 49