Nicole Johnson

Global temperatures continue to climb, and the protection of our electrical infrastructure and the workers who maintain it has become a top priority. Discover how cooling technologies and safety measures keep utility workers and critical equipment safe in extreme heat.

Last year, the month of July reached record-breaking temperatures, making it the hottest month on the planet since 1880, according to data collected from the National Aeronautics and Space Administration (NASA).

As extreme weather becomes the new normal, the safety of workers will continue to rise too. The Occupational Safety and Health Administration (OSHA) began drafting a new heat standard for workplaces last year, which in reality may take years to be ironed out and implemented.

Based on the OSHA report (available here), the consensus was that instead of creating a heat standard, general guidelines for recognizing heat-related hazards, training employees, and creating Heat Injury and Illness Prevention Programs (HIIPPs) should be created instead.

The Bureau of Labor and Statistics (BLS) stated:

• 33,890 work-related heat injuries and illnesses from 2011–2020
• 3,389 per year average
• 999 deaths among U.S. workers from 1992–2021, an average of 33 per year

The heat can affect any industry where workers experience prolonged exposure to its elements, which includes firefighters, farmers, construction workers, miners, boiler room workers, and factory workers, according to the Centers for Disease Control and Prevention (CDC).

Electrical utility workers in particular experience instances of severe environmental heat stress resulting in elevated levels of heat strain when performing daily tasks such as climbing utility poles and installing lines.

 OSHA states under the General Duty Clause, Section 5(a)(1) of the Occupational Safety and Health Act of 1970, employers are required to provide their employees with a place of employment that “is free from recognized hazards that are causing or likely to cause death or serious harm to employees.” Employers are legally obligated to provide a workplace free of conditions or activities that either the employer or industry recognizes as hazardous and or are likely to cause, death or serious physical harm to employees. This includes heat-related hazards that are likely to cause death or serious bodily harm.

What Does Excessive Heat Do to Equipment?

Extreme heat affects workers, but it also affects electrical equipment too. The warmer the environment, the harder the equipment needs to work to keep up with the elements and the greater risk of blackouts and brownouts. Extreme heat reduces the output of power plants, causing equipment to overheat, and make power lines sag as the metal in them expands — bringing them into contact with trees and potentially causing outages.

• Blackouts come without warning, last for indeterminate periods, and are typically caused by catastrophic equipment failure or severe weather.
• Brownouts— defined as a partial, temporary reduction in system voltage or total system capacity.

This has become increasingly true for the U.S power grid system. Unfortunately, the frequency in which these outages have occurred over the years has become alarming. According to Reuters, in the past several years, power systems have collapsed in hurricanes, wildfires, heat waves, and a deep freeze, causing prolonged outages.  It has become apparent that this old grid cannot sustain the current frequency of severe weather storms. The cost of repairs has increased from 2012:

• $160 billion a year in 2022
• 9.1% increase from 2021
• 11.5% increase from 2012

Aside from the reoccurring costs in repairs, excessive heat can significantly impact the electrical equipment in several ways:

1. Transformer overloading: Transformers are critical components of the power grid and can experience reduced efficiency and increased losses when exposed to excessive heat. This can lead to overloading, voltage instability, and potentially catastrophic failures.

Conductor expansion: High temperatures can cause conductors to expand, leading to sagging power lines and increased risk of line-to-ground or line-to-line faults. This can result in power outages, equipment damage, and safety hazards.

• Substation equipment failure: Equipment within substations, such as circuit breakers, switches, and relays, can be adversely affected by excessive heat. This may result in malfunctioning equipment, disrupted power flow, and system instability.

• Increased energy demand: During heat waves, energy demand typically increases as people use more air conditioning and cooling systems. This places additional stress on the power grid, potentially leading to overloading of transmission lines and substations.

• Heat-induced blackouts: In extreme cases, prolonged exposure to excessive heat can lead to heat-induced blackouts, where equipment failures and overloads cascade into widespread power outages affecting large regions, or even entire states.

 The New York Times reported that during the Obama administration, they promoted energy efficiency to address climate change, and consumers used less electricity to save money, but that has changed in recent years as businesses build data centers large enough to power an entire city, or consumers shifted away from gas vehicles to electric vehicles.

With the increased demand for energy, it has become increasingly more difficult for the power grid system to keep up. Most of the system was built in the 1960s-70s and some sections are at least 25 years old. The system is divided into three major regions that are interconnected to local electricity grids designed to ensure minimal loss of service should an outage occur. Due to the grid’s interconnected nature, it can affect many people simultaneously should a blackout or brownout happen.

Last year, millions of people faced unprecedented heat waves across the country. During the high temperatures, cooling is a necessity to prevent overheating, which can lead to hospitalization or death. The U.S. Department of Agriculture reported in 2021:

• A heat wave contributed to 159 deaths in the Pacific Northwest and led to rolling blackouts.
• 9,300 Avista Utilities customers in Spokane lost power in a city of 220,000 people.

There is not a whole lot anyone can do about the warmer temperatures. However, there is plenty to be done to protect workers from heat stress and the equipment they maintain that keeps the power on.

Many organizations are implementing cooling technologies that will help reduce deaths and injuries due to excessive heat and help prevent electrical equipment from overheating.

This article was originally published by Electrical Safety in the Workplace. View the full article here.