Digging Into ERCOT Reliability

We visualize ERCOT unplanned outage data

Digging Into ERCOT Reliability
Photo by Alexandru Boicu / Unsplash
One impact of the Winter 2021 grid failure in Texas was the PUC forced ERCOT to release its Unplanned Resource Outages Report with only a three day lag from operator notice rather than 60 days, which began in July 2021

Maintenance and forced outages are disclosed in the new reporting, including amount of unavailable capacity, plus cause and duration of outage

We utilized the duration and MW of capacity outage to calculate generator outage data by fuel source

140,220 GWHrs of capacity were offline between July 2021 and the data through July 19th, 2022

Natural gas (55%) and coal (13%) generators represent 68% of all outages over the last 12+ months

About That Fossil Fuel Reliability

We used duration of outages and capacity that was offline to calculate monthly outages by fuel type

Comparing outages by fuel source versus capacity tells a slightly different story, solar appears the least reliable (unclear if forced outages include congestion derates), followed by natural gas, coal, wind then nuclear in order of reliability volatility

ERCOT data on outages paints a different picture than perception.  Natural gas unplanned outages appear to be straining the Texas grid the most, however as a percentage of installed capacity, solar may currently be the least reliable.  

We'll continue to watch and report on this data.