South Africa needs an additional 5 TWh of energy a year to keep up with its growing population and meet the energy shortage, states Professor Philip Lloyd of the Energy Institute at the Cape Peninsula University of Technology.

“Renewable energy will help us, but not save us. We need nuclear,” he told several hundred delegates at the PowerGen Africa conference on Thursday, adding that the shortage of energy capacity was "disastrous" for the economy.

Current plans for the energy mix were also discouraging.

“Medupi, Kusile and Ingula have slipped seriously. The hydro component looks unlikely to be completed in its present timeframe. The capacity factors of the coal plant have slipped. The Renewable Energy Independent Power Producer Procurement Programme has been a roaring success. But we have a shortfall. Nuclear is a must,” he told a workshop hosted by Russian State nuclear corporation Rosatom.

Lloyd expected South Africa to go through a hard time for the next three to four years, with a fairly reliable power supply by 2020. He expected nuclear to come "storming in" soon after.

While solar photovoltaic (PV) and concentrated solar power looked fairly sensible, he was doubtful whether hydropower would come in at the level envisaged. He was also worried about the timing around gas.

“Gas is neat, efficient, low-cost and Mozambique has lots of it, but it will take time to develop the infrastructure needed to supply the power stations.”

On renewables, including solar and wind energy, Lloyd was a little circumspect.

“Renewables are the flavour of the year, but there are limits to their growth. Germany reached a point where its wind turbines were stopped, because of overcapacity and grid stability, 15 000 times in March 2015 alone. Intermittency is a real problem. It requires an increased spinning reserve to ensure grid stability…and spinning reserve is very costly.”

Despite its major drive towards renewables, Lloyd noted that Germany had said it still could not do without coal. China had said it would use less coal after 2030, while India expected to use more coal until it had developed other sources of energy.

“If we are to survive beyond 2020, we need to start finding gas and building gas infrastructure soon. We need to increase our wind and PV significantly. We need to find some sources of hydropower that can be brought on stream by early 2020 and plan for a significant nuclear fleet.”

Lloyd said he believed concerns about costs for nuclear were ill-founded and that the power source provided good value.

Power Institute for East and Southern Africa executive director Knox Msebenzi, who also spoke at the workshop, pointed out that only a small percentage of the huge energy resources in Africa had been put to use.

“It’s shame on us [that] on the continent that we have so much energy and so little power.”

He added that sub-Saharan African electricity penetration was about 20% and as low as 5% in some rural areas. In contrast, about 80% of South Africa had electricity, with Botswana aiming to reach 80% within the next couple of years.