Meeting global renewable energy targets will require significant investment in new transmission infrastructure to complement utility-scale renewable energy projects. Without such investments, the energy transition could stall, experts warn.
“Power grids will be an enabler and an obstacle to the energy transition,” says
Edvard Christoffersen, Senior Analyst at Rystad Energy. He estimates an additional 18 million kilometres of grid network, costing around US$3,1 trillion, is required to connect the number of renewable plants needed to curb global warming.
This expansion would increase the total length of global power grids to 104 million kilometres by 2030 and 140 million kilometres by 2050 – a distance comparable to that from Earth to the Sun. Implementing this plan will require nearly 30 million tons of copper to roll out 10 million kilometres of new transmission lines.
There are alternatives to stringing kilometres of copper wire for grid management, according to Christoffersen.
Large-scale battery storage can address renewable intermittency issues and permit higher average grid loads, reducing demand for new lines, he says. “Overhauls and upgrades of the existing grid can increase the capacity per kilometre and digitalisation can free up capacity by solving flexibility issues.”
Distributed energy sources, such as rooftop solar, can also reduce the need for new lines.
The South African situation
In South Africa, the potential of rooftop solar has already been demonstrated, says Jenny Chase, Solar Analyst for BloombergNEF. She points out that, during the worst of Eskom’s rolling blackouts, South African companies and individuals installed a gigawatt of rooftop solar in two months – the equivalent of a medium-sized coal-fired power plant.
“Initially, we were excited and thought the South African solar market would keep growing. We were wrong about that,” she says, pointing out that the South African solar market declined in 2024 because of fewer blackouts.
South Africa faces significant energy infrastructure challenges. Eskom’s National Transmission Company South Africa (NTCSA) estimates 14 218 kilometres of new powerlines, 170 transformers (105 865 MVA), 40 capacitors (2 700 MVar) and 52 reactors (14 713 MVar) are required by 2032 to integrate new wind and solar farms into the grid.
Without further rooftop solar incentives and upgrading of municipal grids to handle this power, the NTCSA will need to start work soon on connecting the 56 GW of new generation capacity expected to come online by 2034.
It also needs to raise the estimated R390 billion needed to pay for the grid expansion. Potential international funders are Germany, France, the UK, the European Union, the Netherlands and Denmark through the Just Energy Transition Partnership from which President Donald Trump has withdrawn the US.
