Texas prepares for extra summertime power outages

Yasir AliMay 19, 2024

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Texas prepares for extra summertime power outages

The Electric Reliability Council of Texas (ERCOT) has issued a warning that reserve margins may be strained as temperatures rise next week, potentially necessitating a directive for generators to postpone non-urgent maintenance.

For the majority of Texas, ERCOT serves as the independent system operator, overseeing the delivery of electricity to over 27 million consumers, or around 90% of the total load in the state.

After urging customers to cut back on their power use throughout the summer to lessen the chance of rolling blackouts, ERCOT has repeated similar cautions many times in the past month.

The main cause of the state’s summer power shortages is the rapid growth in both the population and the economy, which has made it difficult for generators to keep up with the load.

After growing by 1.6% on average every year, the state’s population of 22.0 million in 2003 reached 30.5 million in 2023. Between 2017 as well as 2023, the state’s economy expanded at an average yearly pace of 3.4%, while the national economy developed at a yearly mean of 2.2%.

Consequently, the state’s energy sales had an average yearly growth of 2.1%, rising from 323 billion kWh in 2003 to 487 billion kWh in 2023. The state of Texas has had a growth in power sales that is over three times greater than the national average, which climbed at a pace of 0.6% year between 2003 as well as 2023.

EXPANSION AND SEPARATION

Like other rapidly expanding energy systems, ERCOT has had recurring imbalances between generation and load, including those in China and India.

In a system with rapid development, balancing generation and load while keeping an adequate reserve margin is far more difficult than in one where demand is steady or dropping.

A flat or decreasing load often indicates a large number of legacy generators that are no longer in regular use but that may be relied upon to kick in when reserve margins go low. That is not an option in ERCOT.

The system’s issues are exacerbated by the fact that it has limited connections to other national power networks, making it difficult for it to import electricity in the event of a local shortage.

How to handle prolonged summertime power outages

Texas has made a political decision to limit cross-border connections with other states, thereby avoiding Federal Energy Regulatory Commission (FERC) oversight of its electrical grid.

Until recently, Texas, like other states, rejected the notion of compensating power plants for the extra capacity they retain instead than for the actual electricity they generate. The state has also run an energy-only market instead of a capacity market in an effort to lower total expenses.

Texas relies on elevated wholesale prices to encourage load reductions during times of low profitability and to boost marginal production, instead of investing in reserve capacity that would remain unused most of the year.

Due to widespread air conditioning, daytime loads peak significantly higher in the summer than they do throughout the year, making ERCOT’s balancing issues more severe.

However, during the shoulder seasons of spring and fall, when numerous gas-fired, coal-fired as well as nuclear units are down for maintenance, reserve margins might also be exhausted. Heatwaves that occur later in the autumn or come earlier in the spring strain power supply since many generators have regular schedules.

Reliability managers can give generator and gearbox owners “no touch” instructions, telling them to put off everything except the most critical repairs, in order to restore reserve margins.

Grid managers have the option to request “maximum generation” from available units if that still doesn’t increase buffer margins to a safe level.

The grid’s options are limited to attempting to reduce demand voluntarily, sending out signals urging users to use less power, and, in the worst case scenario, periodically forcibly disconnecting loads.

TROUBLING WITH HEAT WAVES

The spread of crypto-mining activities and data centres, which generate very huge loads, appears to have accelerated increase in power demand in 2022 and 2023.

Nevertheless, whether or not the summer has been exceptionally hot, Texas’s energy usage has recently broken records due to population and economic expansion. Despite this, heatwaves have exhausted available resources and compelled the system to take drastic steps to increase short-term generation and lower load.

Recently, ERCOT has maximised the amount of electricity produced and transmitted resources available during warm weather by depending on no-touch directives, some of which were later rescinded.

It mostly depended on consumer-broadcast emergency notifications last summer to request power conservation during periods of exceptionally low reserve margins. In September of 2023, the state had 2,687 cooling degree days, which is the second-highest number on record after 2011.

As demand for power rises due to the heat wave, the Texas system operator advises conservation.

Due to the unusually high temperatures in August and September of 2023, the grid had to warn consumers and generators many times.

Nonetheless, it seems that load growth has been effectively restrained by the combination of increased wholesale costs and persistent calls for conservation.

When comparing May to September of 2023 to the same time in 2021, there was a 23% increase in cooling degree days, but only a 16% increase in power sales.

Although ERCOT’s recurring balance issues are easily criticised, the system’s issues are a result of its fast expansion, hence having them is a good thing.

In light of the political resistance to connecting with neighbouring grids and the previous lack of a capacity market, ERCOT’s grid administrators have been successful in maintaining system equilibrium.