That's bullshit. I was watching the ERCOT feed [0] during the blackouts, and I never saw it exceed 30%. I posted about it here extensively during the event, and no one reported seeing higher numbers. Right now wind is 5727 MW (23% of installed wind capacity), which is actually a little higher than the average generation I was seeing during the blackouts. PolitiFact very suspiciously doesn't want to say which sources are supposed to support which claims, but I can't find any support for their figures in their ERCOT links, which are the only actual sources provided.

Edit: I did a little more digging, and found that it's your claim that "wind ran at about 50% of capacity" that is completely false. The truth is that only half of the capacity was frozen, but that does not mean that the other half was producing. About half of the unfrozen capacity was not producing for other reasons. The truth is that wind output was 15-30% of capacity due to a combination of factors, including turbines freezing, batteries losing capacity and plain lack of wind. PolitiFact is not outright lying, they're just being as misleading as they possibly can be by cherry-picking stats like "50% was unfrozen" but omitting highly relevant data like "70-85% was offline". That's propaganda, not fact-checking.

[0] http://www.ercot.com/content/cdr/html/real_time_system_condi...