Two things happened last night to contribute to these outages. First, demand was extraordinarily high across the state, Mercado said. And then, beginning at about 1 am, generating units started to shut down. This is almost certainly due to extremely cold conditions. Eventually about one-third of the anticipated capacity went offline. This included a handful of freezing wind turbines, but the majority of the volume losses were due to coal and natural gas plants going offline.
CenterPoint had been planning to manage increased demand overnight and today through rolling outages, which would last about 30 to 45 minutes. However, when power plants began going offline, CenterPoint had to prioritize circuits that fed power to emergency units, such as hospitals and police stations. After this, there just was not enough capacity to implement rolling outages so if your power went out, it mostly stayed out. (Note: If you have power, do your part by conserving energy. If you use fewer watts, access to the grid can be expanded to others).