Yet the minister freely admits that Eskom will be "investing" in wind power, which costs 5.5 times, and solar power, 8.86 times, than what Eskom currently generates power for ("Government poised to sign energy deals," yesterday).

All this for renewable energy and reduced carbon output. Both these sources of energy are unreliable. As they make up a bigger percentage of the input to the grid, an even larger proportion of conventional power stations has to remain on hot running standby to take up the slack at a moment's notice. This is dreadfully inefficient.

At most, wind and solar power can make up 3% of the grid before standby power starts to exceed what is normally available.

If wind and solar made up 100% of the supply to the grid, you would need to have 90% conventional power running in hot spinning standby mode to back it up, which is hopelessly inefficient.

A Dutch study showed that carbon savings from windmills became negative over 3% of the grid supply.

Solar and wind are laudable alternatives and I would support government funding of pilot plants and further research. However, wholesale investment in patently uneconomic processes is wasteful .