/Transmission grid/

High voltage power lines that transmit electricity from the generating plants (Medupi, Kusile, etc) over long distances to local distribution networks. The big pylons you see when you’re on a roadtrip.

When you boiled your kettle for coffee this morning, that electricity used to heat the element was generated almost instantaneously in Mpumalanga. This can be confidently assumed because, unfortunately, Eskom doesn’t have money to buy diesel to run the gas turbines nearer to your home.

That electricity travelled across the 28,000km of high voltage transmission lines, and stepped down to the 325,000km of the local distribution network and into your kitchen.

When President Cyril Ramaphosa announced in 2019 that Eskom would be unbundled into generation, transmission, and distribution, it was in a bid to give each link in the electricity chain the agility to raise funding for its own operations separately.  

Eskom needs about R180 billion to upgrade its transmission infrastructure to meet the already outdated 30GW of additional generation capacity that will come online by 2030 – according to the Integrated Resources Plan 2019 (IRP2019).  

Strangled by debt

A year ago – shortly before Transmission was spun off – Eskom’s outstanding debt totaled around R395 billion. Finance Minister Enoch Godongwana announced in his 2022 budget speech that government is prepared to absorb up to about 60 percent of the power utility’s debt on condition that there is significant investment into nuclear and gas projects.

“Many of the country’s large load centres are situated in major coal production areas, where the transmission grid has been designed to deliver energy to large populations,” explains Enel Energy country manager William Price.

“Historically, the transmission grid was not designed to accommodate renewable energy injections from the largely rural areas where renewable plants are located.”

This map shows South Africa’s current transmission grid – the shaded area is the solar potential:


An Eskom Transmission Generation Capacity Connection Assessment report states that “the country supply areas are limited to about 32.4 GW of new generation capacity.”

Source: Eskom

What’s the solution?

Managing Director of Transmission Segomoco Scheppers says that the business needs investments with a combined value of R72.2 billion over the coming five years to add 2,890km of new high-voltage lines to cope with the agreed projects.

With a further 11,325km needed to accommodate the additional 53GW of generation capacity expected to come online by 2032. A significant portion of this budget will be spent on servitude land procurement.

Developers must also look elsewhere for potential new projects which will also aid community development in underserved areas.

With some 11 major wind farms in the Northern Cape and multiple solar projects also under construction in the region, the low-hanging fruit of South Africa’s renewables potential is almost all harvested.

It seems that Eskom are on to something with the investment into transmission-rich Mpumalanga.