State-owned power utility Eskom’s Power Delivery Projects (PDP) portfolio, currently valued at about R37.5-billion as at March 31, and which falls under the power utility’s Group Capital division, has carried out transmission line and associated infrastructure projects to the value of about R26,5-billion over the last seven years, states Eskom PDP GM Naresh Hari.

Further, about R15.4-billion in project scope still needs to be completed, while a further R14.7-billion has been allocated for addi- tional transmission line infrastructure projects in the next five years.

The PDP portfolio, which comprises about 47 projects presently, focuses on the engineering, procurement, construction and commissioning of new infrastructure and projects for the Transmission division.

PDP projects include transmission line infrastructure and integration projects, such as transmission lines, substations and associated transmission new assets for the new build programme for the Medupi power station, in Limpopo, the Kusile power station, in Mpumalanga, the Ingula pumped-storage scheme, in KwaZulu-Natal, independent power producers integration, and the 765 kV transmission line projects.

Although there was little demand for new transmission line construction and infrastructure in the late 1990s and early 2000s, Hari says, Eskom’s new build programme, particularly Medupi and Kusile, generated demand for new transmission lines and infrastructure.

“The PDP Department plays a significant role in ensuring that the current mega-infrastructure projects are integrated into the bro- ader grid and support growth and development across the country,” he says, emphasising that the transportation of power between the generators and the consumers is vital to the economy.

Engineering News reported last year that, as part of Eskom’s Transmission Development Plan (TDP), projects in North West will include extending the 400 kV and 275 kV networks and establishing a 765 kV network, while, in Limpopo, the Medupi coal-fired power station will be integrated into the power grid and additional transformers will be installed at existing and new substations. Eskom states that Limpopo’s load growth is mainly the result of platinum- group metals and ferrochrome mining and processing activities in the province.

It will also include the integration of the 765 kV network required for the transfer of power from the Medupi power station and the integration of 400 kV to enable load expansion in South Africa’s rural areas.

Meanwhile, the TDP projects for Mpumalanga also consist of extending the 400 kV network, integrating the Kusile coal-fired power station, currently under construction, into the power grid and installing additional transformers at existing and new substations in the province.

Progress on Transmission Integration Projects
As part of the PDP portfolio, the R10-billion Medupi integration project is the largest, with Phase 1 of the integration to be completed in July 2014. Transmission lines have been constructed from Medupi to Spitskop, from Medupi to the Marang substation and from the Spitskop substation to Dinaledi, says Hari, and that the first phase of 870 km of transmission lines and 580 MVA for transformation capacity will support units 6, 5, 4 and 3 at Medupi.

In addition, the high-voltage yard at Medupi has been completed and energised from the grid. PDP is ready for the transmission integration of the first unit at Medupi, which is to be synchronised in the second half of the year.

Phase 2 of the Medupi integration, for which the PDP recently received approval, will comprise the construction of two new substations – Ngwedi, near Mogwasi, in the North West, and Borutho, near Mokopane, in Limpopo – as well as the erection of transmission lines from Medupi to both substations, which will interlink with the rest of the grid, which consists of 732 km of transmission line and an additional 2000 MVA of transformation capacity.

This phase is expected to be completed at the end of 2016 and will link Medupi’s units 1 and 2 with the grid. “While the PDP faces challenges such as environmental authorisation and land acquisition, we are still very much on track to meet all milestones within the generation integration,” Hari emphasises.

Meanwhile, the PDP energised the substation at the Kusile power station in December last year in preparation for integration of the first unit, which is expected to come on stream in 2015. “Further, we continue building the lines for the next units to ensure that the PDP provides sufficient transfer capabilities when the other units come on stream,” he adds.

In addition, Hari notes that energisation of the Ingula substations in KwaZulu-Natal, which also falls within the PDP portfolio, will be completed this month. The integration work yet to be completed to link the Ingula Pumped Storage Scheme to the Ingula substation requires the laying of 4 km of 400 kV cable.

The Clean Technologies Projects include ongoing work in the Ingula Pumped Storage Scheme tunnels and when work is completed, the PDP will lay the cable to connect the generation switchgear, which gets power from the turbines, to the transmission substation.

“However, the PDP hopes to receive access this month and estimates it will complete the laying of the 400 kV cables by February 2015,” he adds.

The Greater East London Strengthening Project
Another PDP portfolio project is the Greater East London Strengthening Project, for which PDP needs to build a transmission line from the Eros substation, near Harding, KwaZulu-Natal, to the new Vuyani substation, in Mthatha, and the Neptune substation, in East London, both in the Eastern Cape. The PDP commissioned the new substation at the end of March.

The line between the Vuyani and Neptune substations was also completed at the end of March; however, about 25 km of line still needs to be constructed between Eros and Vuyani. The PDP expects the project to be completed at the end of this year.

“It was probably one of the most difficult projects that we have undertaken, as the whole project falls within treacherous and mountainous terrain, with high rainfall further inhibiting construction of the line,” he says.

Owing to the significant number of projects and demand for new infrastructure, Hari says, there has been a significant increase in skills growth in project management, construction skills and engineering over the last ten years, while transmission line construction capability has quadrupled in the last seven years.

“As South Africa needs the new infrastructure, we had to re-establish the whole skills base for transmission, with a focus on both in-house and contractor skills,” he explains.

Hari adds that the utility’s next ten-year plan is to create interest amongst the youth to join the power generation and power delivery environment, and to show the construction industry the potential capital and skills investment opportunities.

“The demand for skills development will still increase, owing to the significant volume of projects, valued at R30-billion that needs to be executed in the transmission space over the next five years” Hari concludes.