ERCOT is a bazinga system operator set up by the characters from looney tunes. They're the only system operator without a forward capacity market. Everyone else pays uneconomic reserve plants money just to stay connected and ready to respond to demand spikes, but the brain trust at ERCOT decided it would be cheaper for rate payers to not do that. Turns out it is until it isn't, and the only way they have to balance supply with demand is to curtail demand with eye bleedingly high real time prices since there isn't enough slack in the system.