The article doesn't explain very well... But this is all about getting more electricity down the same wires. On a cold windy day the wires are cooled more. Wh

The article doesn't explain very well... But this is all about getting more electricity down the same wires. On a cold windy day the wires are cooled more. Which means you can pump more amps through them without risk of failure - sometimes 100% more! However, grid operators aren't able to make use of that ability because grid operation is typically scheduled hours in advance - since classical power stations take hours to start/stop. However if you have a reliable weather forecast a few hours out saying it will be cold and windy, then you can safely schedule in some combination of power producers and consumers which would otherwise put a particular link over capacity.