So the bottomline on all this is an extra charge for lots of customers in order to ensure reliability.
Reliability, and price spikes depending on your contract for power.
...It was an unusually hot Texas day in late February and, per usual, Houston was causing trouble.
By late afternoon on Feb. 22, temperatures around the state had climbed into the 90s, and the demand for power surged. In Houston, where midday wholesale power prices typically hover around $25, the price spiked to $4,000 per megawatt-hour - a sign that the market was short of supply.
The problem, though, likely wasn't production; generators were making plenty of electricity. They just couldn't get it to Houston because transmission lines didn't have the capacity to carry it all....
...For the past two years, the transmission bottleneck in Houston has been the worst in ERCOT's power grid.
The problem has intensified as Houston's population has grown, adding to demand that overloads the transmission lines.
Studies by ERCOT have found that transmission lines could become so congested - think freeway gridlock that brings traffic to a halt - that blackouts at times of peak demand could hit Houston by 2018....
https://www.brazosvalleyconnection.com/centerpoint-project-aims-to-bring-congestion-relief-to-power-prices