Get energy facts right

DEAR SIR — David Gleason’s rant on renewable energy (SA’s bottomless pit for renewables, April 10) reminds me of the dark days of the HIV/AIDS denialists. If one repeats lies, untruths and half-truths often enough and loudly enough, then some of them stick and people start to believe they are true.

The costs of the various generating sources of electricity certainly differ, between renewables and coal, and nuclear, and even between individual coal-fired stations, depending on age, technology, coal source, etc.

Electricity suppliers, including Eskom, always attempt to minimise the total cost by using generators with the lowest cost, and perform these balancing adjustments on a minute-by-minute basis. Today we have almost no spare capacity in our base-load generators and Eskom must be hard put to attempt any optimisation, although it certainly uses the very expensive gas turbines only when absolutely necessary.

But Mr Gleason is wrong when he says that “when everything else is working … the wind power isn’t required. It can’t be stored so goes to waste”, and again when he makes similar statements regarding solar panels.

In the present situation in SA, we have a very substantial baseload for 24 hours a day, 365 days a year, which is mostly met by coal. Once the capital cost of a wind farm or photovoltaic farm has been invested, the incremental cost of the power produced when the wind blows or the sun shines will be very low, and can immediately be utilised in full by the national grid, leading to savings on other, more expensive, generators.

The mechanisms to do this are in place and in use continually, so it is a nobrainer for Eskom.

The big argument is really whether we should invest in our future, and that of the whole world, by shifting to renewables and reducing our carbon output. It is obvious where Mr Gleason’s opinions lie, but let’s at least have our basic facts right.