PD Naidoo & Associates Cape Strengthening Programme
ACER (Africa) Gamma-Omega 765kV Transmission Line
PBA International (SA) Draft EIR Report
CHAPTER 3
OVERVIEW OF THE CAPE STRENGTHENING PROGRAMME
TABLE OF CONTENTS – CHAPTER 3
1. ESKOM TRANSMISSION’S OBJECTIVES AND MOTIVATION FOR THE PROPOSED 765kV TRANSMISSION LINE 1
1.1. The Cape Strengthening Programme 2
2. Strategic considerations and alternatives 4
2.1. Eskom Transmission’s Commitment to purchase locally (IPP) generated electricity. 5
2.2. Clarification of the “No Go” option 5
2.3. ‘Below the ground’ option for visually sensitive areas 6
3. DESCRIPTION OF THE PROPOSED DEVELOPMENT 6
3.1. Location 6
3.2. Nature of the Proposed Development 7
3.2.1. Associated infrastructure 7
3.2.2. Technical aspects of a 765kV Transmission line 8
3.2.2.1. Technical dimensions 8
3.2.2.2. Proximity to other infrastructure 8
3.2.2.3. Technical costs 9
3.2.2.4. Pylon towers 9
3.2.2.5. Servitude details 10
3.2.2.6. Transmission line construction process 11
3.2.2.7. Operation 11
3.2.2.8. Decommissioning 16
3.3. Anticipated programme of planning and implementation 16
4. EIAS AND THE PLANNING PROCESS OF A TRANSMISSION LINE 17
4.1. The planning process 17
4.2. General Comment 18
APPENDIX 3 1
APPENDIX 3A: ESKOM STRATEGIC DOCUMENT 2
APPENDIX 3B: SERVITUDE DETAILS 3
C3 Overview of the Cape Strengthening Programme ver 5.doc - II -
PD Naidoo & Associates Cape Strengthening Programme
ACER (Africa) Gamma-Omega 765kV Transmission Line
PBA International (SA) Draft EIR Report
OBJECTIVES OF THIS CHAPTER
The decision to conduct an Environmental Impact Assessment for the Gamma-Omega 765 kV Transmission line has been taken by Eskom Transmission as part of its reasoning for the Cape Strengthening Programme. As such, the project should not be viewed in isolation; rather, it should be viewed within the context of Eskom Transmission’s overall strategy for electricity provision to the Western Cape.
The planning process for a Transmission line is a complex one, comprising various technical and administrative components and timeframes. This Chapter sets out Eskom Transmission’s objectives for electricity provision, the motivation for the Cape Strengthening Programme, details about the proposed development, the planning process for a Transmission line, servitude negotiation process and how these relate to the Environmental Impact Assessment process.
1. ESKOM TRANSMISSION’S OBJECTIVES AND MOTIVATION FOR THE PROPOSED 765kV TRANSMISSION LINE
As an independent, self-financing utility company, Eskom is responsible for the provision of reliable and affordable power to South Africa, and thus, plays a vital role in sustaining and stimulating South Africa’s energy-intensive and dependant economy. By maintaining low electricity costs and a reliable supply, Eskom enables South African producers and manufactures to remain competitive on world markets, to contribute to employment opportunities and generate wealth. To give effect to its mandate, Eskom Transmission maintains a national network (the National Grid) of high voltage electricity supply between the various power generation facilities and distribution centres that distribute electricity at a local level (e.g. municipalities). However, the growing demand for electricity (predominantly for domestic and industrial use) is placing increasing pressure on Eskom’s existing power generation and transmission capacity. It is within this context that Eskom Transmission has identified that the current capacity for the South Western Cape needs to be upgraded to meet projected future demands. The functions of Eskom Transmission must be separated from those of Generation and Distribution. Thus it will retain sole responsibility for the maintenance of the National Grid.
To better understand the need for additional transmission capacity and the proposed solution, the complex generation and delivery system requires further explanation. As electricity cannot be stored it is necessary that the system generates and delivers power instantly to the source of demand, over vast distances across South Africa via high voltage power lines, mainly from power stations located at coal fields situated in the Mpumalanga Highveld. The power is then transmitted to major Sub-stations where the voltage is down rated for distribution to industry, businesses, homes and farms.
The grid system that supplies specifically to the South Western Cape operates in the following manner:
A combination of 400 kV and 765 kV transmission lines feed electricity from power stations in Mpumalanga Province to 14 transmission Sub-stations situated across the Cape Province.
The electricity supply to the Southern and Western Cape and Namibia is supplemented by the generation output of the Koeberg Nuclear and Palmiet Hydro Power Stations.
Operating at full capacity (i.e. including power from the Palmiet Power Station and all lines operational from Mpumalanga) the transmission network which currently consists of only 400 kV Transmission lines, can supply 3 400 megawatt of power to the Western Cape. Peak demands over the last few years show levels reaching 3 000 megawatt. Therefore the network is approaching peak capacity, which could potentially result in more outages.
Should one of the 400kV Transmission lines fail, the 3 400-megawatt capacity of the network is reduced to 2800 megawatt, thereby placing the network under severe strain. This potentially places at risk industry dependent on a reliable supply of electricity.
Demand projections are an uncertain science and are currently under review. However, the latest projection is that in addition to improve reliability immediately, there will be a need for increased capacity by 2008 to meet the projected demands. Such is the planning timeline for such developments (see section 3.2.1) that the planning process needs to be implemented immediately. The EIA process is one of the initial phases of the entire planning process.
Eskom is committed to undertaking its activities in an environmentally responsible manner. Eskom not only complies with environmental legislation, but has also developed its own environmental policy, and, for example, has been undertaking environmental impact assessments prior to them being a regulatory requirement.
1.1. The Cape Strengthening Programme
The Cape Strengthening Programme forms part of the transmission network that operates between the main power generating facilities in Mpumalanga and the receiving environment in the Western Cape region. Particular focus is given to the network south of De Aar, where transmission is more limited (Figure 1).
The Cape Strengthening Programme originally comprised a range of projects that are in various phases of planning and development with the aim of improving the reliability of electricity supply to the southern areas of the country, and in particular to provide for the growth in electricity demand in the Western Cape. The individual projects included proposed upgrades to capacitor stations and sub-stations along the route as well as the development of a new 765kV Transmission line which is the focus of this report. Individually and collectively these individual projects address two key aims of the overall programme:
The Cape Strengthening Programme aims to improve the reliability of the existing transmission network, and
It will upgrade the electricity transmission capacity of the network in the short-term.
The associated projects in the Cape Strengthening Programme that propose upgrades at capacitor stations and sub-stations along the route will serve to improve the reliability of the network to a certain extent, but when major failure occurs, such as a line failure, these measures will have a limited impact.
The 10 projects that comprised the Environmental Impact Assessment (EIA) initiated late in 1999 are outlined in Chapter 2, section 2.1. Most of these projects related to capacitor and sub-station upgrades with the exception of two projects: a new switching station near Tulbagh and a new 765 kV Transmission line from the Gamma to Omega sub-station sites. It is the nature of projects of this size and complexity that they are constantly under review and planning. As such this project was placed on hold for the following reasons:
Site investigations revealed that certain projects would not be viable.
Viewed against a regional strategy, other projects would not fall within the short-term plan (five years).
The proposed upgrades at certain sites were revised.
Strategic maintenance on existing networks.
The outcome of this review included the cancellation of five of the projects, fast tracking four of the capacitor and sub-station upgrades, and the continuation of the 765 kV Transmission line study.
It is important to note that the nature of the Cape Strengthening Programme allowed for each of these projects to be viewed as independent components that will contribute to an improved reliability of supply. As such, their viability is unaffected by the cancellation of the other projects from the short-term programme. Their implementation may therefore proceed without the parallel implementation of the other projects in the programme. Chapter 5 contains two Background Information documents that detail the original Cape Strengthening Programme and the revised programme. The reasons for the change in status of the various projects and the level at which the EIA studies were conducted are summarised in the second Background Information Document. Four Scoping Reports were submitted early 2001 and Records of Decisions were issued for these projects.
The Impact Assessment investigations for the 765 kV Transmission Lines recommenced in June 2001. This Draft Environmental Impact Report (EIR) documents the approach adopted for this study and findings of the environmental investigations.
2. Strategic considerations and alternatives
The planning for the Cape Strengthening Programme has not been carried out in isolation to Eskom’s overall strategy to meet its mandate. A copy of this strategy document is included in Appendix 3A. It is against this background that the strategic considerations are raised. An important aspect of the aims of the Cape Strengthening Programme as a whole, and particularly the proposed 765kV Transmission line is the short-term focus (i.e. in the next five to eight years). At present there are feasibility and pre-feasibility studies underway considering alternative sources of power generation for the Western Cape. These include the gas-fired turbine facility associated with the Kudu Gas supply, the Pebble Bed Modular Reactors (PBMR) and wind turbine facilities. While it is not within the scope of this study to investigate these as alternatives to the proposed development, it is worth considering these initiatives from a planning perspective.
The following points are relevant:
The currently proposed alternative sources of power are still very uncertain (including Kudu Gas, PBMR, wind farms, etc.).
The PBMR and wind farm proposals are for pilot schemes and are together unlikely to provide the necessary additional power in the short-term.
There is existing additional capacity in the power stations in Mpumalanga, and if required this can be provided in a relatively short timeframe.
The planning process itself requires significant time and to be prepared for the projected demand requirements in 2008 the planning process needs to be underway now (as it is through this EIA study).
The power generation alternatives do not provide for transmission in themselves, and the transmission network still needs to be provided.
It is acknowledged by Eskom Transmission that implementation of a facility such as the proposed Kudu Gas Fired Power Station may delay the need for constructing the new Transmission line. However, it is still expected that the proposed new line will ultimately be required. As such the planning process (of which this EIA is a significant element) is still relevant.
On the basis of these considerations, the motivation for the planning of the proposed 765kV Transmission line is seen to be robust. Further investigation of wider, more strategic, alternatives to the proposed line in this EIA study is therefore not intended. However, it is expected that prior to the construction of the line, the existence of the line in the context of the more strategic alternatives will be reviewed.
2.1. Eskom Transmission’s Commitment to purchase locally (IPP) generated electricity.
Eskom Transmission is committed to supplying ‘bulk’ electricity at the cheapest price. This implies that there is a balance between the sale price of electricity at point of generation and the cost of transmitting it over a distance. It is understood from Eskom Transmission that, under the present situation in the energy sector, there is no commitment to purchase from any particular source, and that the most economic option is given priority at any given time. In turn, this will be balanced with demand.
Therefore, the economic viability of the proposed Transmission line should be kept under review, and only constructed after that viability has been illustrated.
2.2. Clarification of the “No Go” option
As previously stated, the Cape Strengthening Programme has two main objectives:
To improve the reliability of the existing transmission network, and
To upgrade the electricity transmission capacity of the network in the short-term.
The latter will enable future additional electricity demands to be met. Under current forecasts, the full capacity of the existing network will be exceeded by 2008. This is based on the assumption that other generation sources may not be available by then.
However, there is also considerable concern that “outages” (wide area power failures) will increase in the interim as the demand grows closer to the full capacity of the transmission network (refer to Appendix 3 of this Chapter) for a more technically detailed breakdown of demand and capacities). During periods of high demand (e.g. winter) maintenance on any aspect of the network has to be carefully planned, as any additional and unforeseen failure may result in the entire area “tripping” in much the same way as a household network will trip when a certain point is overloaded.
Incidents when this may occur is when one of the two Koeberg units is shut down for refuelling and a forest fire occurs under one of the lines near Wolseley and should be shut down. There have been a number of reports during the public involvement programme on this study where fire fighting has been severely hampered because Eskom would not shut down a line. They were not able to do it without switching off the greater part of the Western Cape. Conditions such as this decrease the reliability of the network and limits maintenance. The most recent incident occurred in October 2001 when a power failure affected mush of the Western Cape area.
Outages, power dips or power surges can have significant cost impacts on industry in particular as computer operated equipment and timing equipment can be affected.
Hence, the “No Go” option would result in greater instability in the transmission network in the short-term, with potentially significant cost implications, and that this will be exacerbated by reduced maintenance on the network due to limited opportunity to switch the lines off. Hazards such as forest fires will potentially worsen, as fire fighting cannot take place under the live lines. Additionally, the capacity to meet future demand growth will be delayed unless the planning for the line is put in place now. Even with the implementation of the Kudu Gas Fired Power Station, the need for the proposed 765kV line is still anticipated.