Article from Richard Arderne

I asked my son Chris, studying engineering masters in Stockholm, specialising in energy, what he thinks SA should do to solve its energy problems, and this is what he replied:

Basically I think the discussion is quite simple:

1) Increase energy availability
2) Drastically reduce carbon emissions

1) Decommission coal plants
2) Replace them with something

1) Useful energy storage is further away than the lifetime of renewable sources
2) South Africa has no neighbours with whom to trade electricity

1) Build renewables up to a practical limit for grid reliability (maybe 30%, we’ll have to see)
2) Build nuclear
3) Decommission coal plants as the economy and grid allow

1) If energy storage becomes practical and economical in the future, to the point that it is competitive with nuclear, then build more renewables.


Bridging the Gap?

Many say we should push for wind and solar, and presumably keep using coal and gas to fill in the gaps. But when 18 GW (40% of the country’s current capacity) has gone offline by 2030 (rough planned decommission timeline), what happens? There’s no way any energy storage technology will be cost-competitive yet (in South Africa) to replace that.

The other frequent suggestion is to replace the coal with gas, which would lead to marginal carbon improvements (although great air pollution improvements), with much higher prices and no significant domestic gas resources. It’s possible I’m wrong and storage technology improves more quickly (there are some promising CSP concepts), but the scale that would be needed and the inefficiencies in any storage system, means it would have to build perhaps four times the capacity.

South Africa is basically an island, and most comparisons from the US/Europe are not valid. Germany has gone all out with wind, and is suffering, but it hasn’t been a complete disaster, because they’re connected to a huge European grid. And they’re busy planning 27 new coal plants, which is the last thing anyone should be doing. And in that case it’s difficult to get more than maybe 30% from intermittent sources, and already then we’ll be seeing many instances of excess production. Renewables have grid priority, so the coal plants will have to shut down, which is expensive and damaging. Or the electricity price falls hugely, or even goes negative, as has happened in Germany and parts of the US. Both of these are bad, and will cost Eskom millions.

I think the current wind and solar trend in South Africa is probably great. I’m not sure what the overall effects are on the coal fleet (efficiency and breakdowns) but the rate of renewable installation is probably slow enough that it can be monitored before anything drastic happens. So although the renewables increase the carbon/kWh of the coal plants, they decrease the overall country’s carbon/kWh, and appear to be profitable. So keep going with that, but don’t expect it to be a majority contributor any time soon.

The anti-nuclear viewpoint often ignores two things: the need to hasten the decommissioning of the coal plants, as well as the fact that the relationship between demand and supply is not unidirectional. The renewables being installed are reducing overall carbon emissions, but do not allow Eskom to decommission any coal plants. And that should be a big priority: shut down the older, more polluting plants as soon as possible. Additionally, South Africa is suffering energy poverty and it is impacting the economy in a huge way.

So while nuclear probably isn’t critical to restoring a balance, having more capacity allows one of two things: more supply and thus more incentive for industry growth, or the possibility to shut down old plants.