Nuclear the best bet (29 November 2011)

Published: 2011/11/29 08:06:31 AM

David le Page (Stop giving the government a free pass on nuclear power, November 25) falls into the trap of assuming that nuclear and renewable energy are alternatives. His article on nuclear generation begs a fundamental question: how much sporadic renewable energy input can the national grid tolerate?

It is obvious that the last source of energy that an organisation such as Eskom, committed to supplying reliable electricity, would willingly use is wind.

Spreading wind farms all round the coast on the basis that the wind must surely be blowing somewhere is an expensive, aesthetically displeasing and technically unsatisfactory solution. Solar energy is a better bet, but does not help at night.

Clearly, small percentage swings in the energy input to the grid can be met by firing up or down conventional back- up generation plant. Equally clearly, large energy swings could not be met in this way and could well lead to power failure. Transmission engineers suggest informally that 5% variable energy input could be accommodated but that more than 20% or 30% would give problems, even with major expenditure to "smarten" the grid.

That we do not have firm data is unsatisfactory but not crucial to the argument. It is obvious that — protestations by Greenpeace and WWF notwithstanding — intermittent energy sources can supply only a percentage of our needs and probably a small percentage. Once that is acknowledged, it follows that the bulk of our energy supply must come from reliable fossil- burning sources or from nuclear. Given the international pressure to reduce carbon dioxide, it would be folly to abandon the planned nuclear programme. Nuclear and renewable energy are not alternatives. France has shown that nuclear can economically supply virtually all the nation’s needs. Renewables can help, but no more than that.

John Walmsley
Nuclear Institute, Simon’s Town

Business Day
29 November 2011