Interconnected grid for energy security

On February 2021, the biggest state in the most developed country in the world, Texas, USA, faced an unprecedented event. Due to hurricane Uri, the Texas electricity grid was forced to shed a load, a lot of it. It left 4 million Texans without power for almost seven days.

- AASHISH CHALISE

The power cut killed approximately 246 Texans, as reported by the state; other reports are grimmer, with more than 700 fatalities. The total economic loss was an astounding $125 billion.

A state considered an energy powerhouse faced such devastation, but surrounding states affected by the same hurricane fared much better. Case in point, Oklahoma, which borders Texas from the north, was also hit by Uri, in similar strength, but only lost power for a few hours, and the grid was restored right after. More importantly, no lives were lost. Why were these two cases so different? A lot of light has been shed in the aftermath of Uri on what went wrong and why the Texas power grid, managed by the Electricity Reliability Council of Texas (ERCOT), could not handle the power flow. In an electric power grid, the demand must match the supply. If there is a variance, the power system's frequency is affected, resulting in grid failure. On February 14 and 15, 2021, a series of events forced ERCOT to curtail power. The demand for electricity due to the very large-scale weather events (VLSWES) had risen to 68 gigawatts. Households began using energy-inefficient heating systems installed in most Texas homes to fend off the extreme cold.

At the same time, natural gas plants, which could not handle extreme cold, started shutting down.

ERCOT had no choice but to curtail power to save the entire grid. If curtailment did not happen on time, the entire state would have lost power and getting the power system back would have taken up to a month. In essence, they did save the overall grid but at the cost of many lives. Governor Abbott even blamed the wind plants for the catastrophe, which he later corrected as wind is only a tiny percentage of the Texas electricity generation mix.