In Don Quixote, the book by Cervantes (you know, Don Key Oatie – the one where he is a knight who has a horse called Rocinante, pronounced Ros-sin-antey, and a servant, Sancho, and there is a donkey called Dapple and Donnie is a bit off his head, you know) there is a quotation which is: “The truth may be stretched thin, but it never breaks, and it always surfaces above lies, as oil floats on water.”

So, thus educated, let us turn to the matter of an article by Andrew Kenny. The article is titled ‘Renewable energy is a disaster and will collapse SA’s electricity supply system’. It is hard hitting. Kenny states: “Week by week, the greens tell us the price of renewable energy is coming down but all around the world the cost of renewable energy is going up.

“It is far more costly than anyone predicted 20 years ago and getting worse all the time. The system costs are ignored by green energy modellers.”

Kenny calls the Council for Scientific and Industrial Research’s energy model “absurd”, adding: “Under this mad plan, the ‘least-cost option’ is a mixture of renewables and a ‘flexible’ energy source, meaning gas – which would be imported. In fact, South Australia did implement just such a plan, and the results were even more disastrous than expected.”

In reply to this article, we have an article from Phillip Mechanick. He disputes Kenny’s interpretation of South Australia’s renewable-energy woes and calls Kenny’s article “a poorly researched ideological attack on renewables”. Fighting talk indeed.

In August 2016, I wrote an article titled ‘Nimble operators with gas turbines’. I pointed out the massive jump in energy prices in South Australia in 2015 and 2016, when the last coal-fired power station closed down. The increase was due to there being no coal-fired power, a reliance on wind, the absence of wind and the use of gas turbine power from Torrens Island.

Mechanick writes that there was, in fact, no failure of renewable energy in South Australia; it was all due to a poorly maintained grid and political agendas. He further writes: “The Liberals, having beaten Labor in the South Australia state election in March 2018, abandoned their position that the Labor target of 75% renewables by 2025 was ‘ideology and idiocy’ and are going ahead full speed to meet that target. Now the Liberals only differ with Labor on going a bit slower in phasing out coal.” This is a very interesting paragraph, since the last South Australia coal-fired power station, Port Augusta, closed down in 2016. Coal could not be more ‘phased out’ if it tried.

I know Kenny. He is one of the few people I know who is capable of distilling electrical engineering thought into common sense. I do not know Mechanick, other than he is a member of the Grahamstown Residents Association. However. I have highlighted this debate, since it is part of the much bigger, ongoing debate between degreed, qualified, registered professional engineers (such as Kenny and Mackenzie-Hoy) and those who have never run a power system – I have).

Yes, it is a debate. But it is between the informed and uninformed. The qualified, with years of experience (electrical engineers and physicists) with the public. The desirability or not of renewable energy is a very hot topic. Those that wish to debate with each other may as well, like Don Quixote, attack windmills, believing them to be giants. But all must agree on one thing: renewable energy is not reliable. There are windless nights when you need power from other sources. Gas turbines are expensive to run. Coal-fired power stations cause pollution. Nuclear power is very reliable but distasteful. You cannot hope to have a generation system with just one of these. So, remember: “These truths may be stretched thin, but they never break.”