Transmission Integration of Nuclear 1 Bantamsklip Site November 2009

Transmission requirements for new power stations on the Grid Why power stations in the Cape? Why must they be large power stations? What is the long term strategy for the development of the transmission grid?

Capacity Planning vs Transmission Planning (a) Load Demand Forecast 40 GW (b) Capacity Plan RTSCoalPS etc. 40 GW (c) Capital project funnel >40 GW Volume & typeSpatial & transportation

Current Transmission power flow (c) Capital project funnel (a) Load Demand Forecast (b) Capacity Plan 40 GW RTSCoalPS 40 GW >40 GW Current power pool –Generation exceeds local load –Other load centres require imports –Tx designed to feed load centers from power pool

Impact of location on corridors - Inland Scenario (c) Capital project funnel (a) Load Demand Forecast (b) Capacity Plan 40 GW RTSCoalPS etc. 40 GW >40 GW Inland Scenario –Large coal –Spatial project location –Nearest Gx feed nearest load –Large northern Tx corridor Capacity Roll out –Matching capacity scenario plan with available project

Impact of location on corridors - Coastal Scenario Issues to Consider Servitude and EIA restrictions Lead times: –Long Tx lines years –Power stations 8 – 10 years Use all appropriate proven technology available –HVDC, EHV AC, HVDC conversions of existing AC lines Transmission technology choice must be compatible with strategic power system development plan Coastal Scenario –Large nuclear displacing generation from the north to the coast –Reduced northern corridors –Reversing flow & increased corridor size Same Capacity Plan for each scenario Vastly different Tx plan Huge transportation risk!

Objective of Development of the Transmission Grid Connect Generation to the closest Load Centre Use existing infrastructure as far as possible Have a robust network – not an optimal network Require phased developments to line up with long term requirements

Transmission Requirements for Integrating a Large Power Station Must be able to transport the power from the power station to the load centre where it is required (i.e. move it through the network) Must be able to evacuate all the power out of the power station after losing one transmission line Must still be able to evacuate reduced power after the loss of two transmission lines and maintain system stability Generators must remain stable on the loss of any two transmission lines Generators must stable after the loss of a generator unit

Transmission Power Corridors & sites

Transmission Power Corridors & the Sites S T K C1 C3 C2 Power Corridors A B NUCLEAR SITES B = Bantamsklip K = Koeberg T = Thuyspunt S = Schulpfontien Z = Brazil B Z

Thuyspunt Nuclear 1 Transmission Requirements 2 x Thuyspunt-Dedisa 400kV lines 1 x Thuyspunt-Grassridge 400kV line New 400/132kV P/E Substation 2 x Thuyspunt-New PE S/S 400kV lines 1 x New PE S/S-Dedisa 400kV line 1 x New PE S/S- Grassridge 400kV line

SOW: Thypunt Option

Geographic layout: Thypunt Option 1x Thyspunt-Grassridge 400kV line 2x Thyspunt- Dedisa 400kV lines 2x Thyspunt- PE s/s 400kV lines 2x G/D-PE s/s 400kV lines PE s/s Dedisa Grassridge THYSPUNT

Koeberg B Nuclear 1 Transmission Requirements 3 x Koeberg B - Omega 400kV lines 1 x Koeberg B - Philippi 400kV line 1 x Koeberg B - Stikland 400kV line

SOW: Koeberg Option Acacia Smelter Muldersvlei Stikland (Old)Koeberg Ankerlig 9x150MW Aurora JunoHeliosAries Omega Gamma Droerivier Palmiet Poseidon Grassridge Bacchus Proteus Hydra 2x900MW Mosselbay OCGT 5x150MW To Perseus To Beta To Delphi 2x200MW Future Gx site Existing Gx site 400kV 765kV Kronos Koeberg 2B 3x1117MW Dedisa PE Kappa 2x New 400kV line Philippi To Perseus 1x 400MVAr SVC at Perseus/Beta 1x400MVAr SVC

Geographic layout: Koeberg Option 2x 400kV line Duynefontein to Stikland (via Muldersvlei) 1x 400kV line Duynefontein to Philippi Muldersvlei To Philippi Omega Koeberg 1 st Kappa to Omega 765kV line 3x 400kV lines Duynefontein to Omega KOEBERG B

Bantamsklip Nuclear 1 Transmission Requirements 2 x Bantamsklip-Bacchus 400kV lines 1 x Bacchus-Muldersvlei 400kV line 4 x Bantamsklip-Kappa 765kV lines

SOW: Bantamsklip Option Acacia Muldersvlei Stikland Koeberg Ankerlig Aurora Juno Helios Aries Omega Gamma Droerivier Palmiet Poseidon Grassridge Bacchus Proteus Hydra 9x150MW Mosselbay OCGT 5x150MW To Perseus To Beta To Delphi 2x200MW Future Gx site Existing Gx site 400kV 765kV Aries Possible 3x1117 Dedisa PE Kappa Smelter 2x New 400kV line 3x2000MVA + 1x2000MVA 2x 2000MVA 6x2000MW2x 2000MVA 1x 400MVAr SVC at Perseus/Beta 1x400MVAr SVC

Geographic layout: Bantamsklip Option BANTAMSKLIP Kappa Bacchus Droeirivier 4x 765kV lines PSI to Kappa PSI s/s 4x765/400 TRFR’s 1x additional Bacchus- Muldersvlei 400kV line 4 x 400kV Lines 2 x 400kV Lines

Transmission Line Route Requirements Most direct route preferred –Capital cost –Transmission losses (operating) Minimum number of bend points –Angle towers significantly larger and have larger visual impact –Angle tower costs increase dramatically –Maximum bend is 60 o Routing –Lowest visual impact –Least exposure to elements –Ease of construction and maintenance

Transmission Security Requirements Power station generators must remain stable for the loss of two transmission lines Network not designed to withstand the loss of more than 2000MW in a single event Risk of loss of a power station must be minimised to avoid system blackout Thus Bantamsklip requires 3 Corridor Routes Max no. of lines (circuits) per corridor is two Routes to be separated as far as possible (target minimum is 2km)

Transmission Line Technology Overhead Lines –Construction simple –Insulation is self healing –Maintenance and repair easy –Land underneath still viable for agricultural use Underground Cables –No 765kV available – highest is 500kV –Not self-healing –Heating and electromagnetic issues –Finding and repairing faults a major issue –Large bending radius – therefore straighter routes required and going though mountain ranges extremely difficult –Land above effectively sterile

Underground cable vs Overhead conductor

The excavations for 400kV underground cables

Nuclear 1 Sites Questions ?