Yesterday was a good day for wind after a slow start. Across the 24 hours from 6am yesterday to 6am this morning the supply ranged from 0.8GW to 3.2GW.
The average for the day was about 44% of capacity which is better than the 30% you expect for a year.
The critical period is the low point, the bottleneck or the choke point. The supply only briefly touched the low point but there was a period of almost 2 hours below 1.2GW or 20% of capacity.
That came at a low point of demand and so there was no drama and there will not be an issue most of the time as long as the base of hydrocarbon power and hydro is solid.
But the base is threatened and that was a good day. Remember the day in the sample year when wind delivered less than 3% of capacity and the 29 days under 10%.