COLUMBUS, Ohio (WCMH) – A continuing power outage for more than 100,000 people had AEP Ohio playing arbiter on who and which places would lose electricity, as the company tried to manage strain on its storm-damaged infrastructure.
AEP Ohio had to take certain steps to reduce or cut power altogether at the order of its regional overseer, PJM Interconnection, to avoid a more widespread power grid failure.
“Similar to kinking a garden hose and leaving the water on, if there is enough water pressure and the kink is strong enough, the hose could burst,” AEP Ohio wrote in an FAQ Wednesday. “The overloading of the transmission system creates risk … [for] blackout events that can take weeks or months to recover from.”
Electrical companies refer to the practice of reducing power strain as load-shedding, and there are two ways utility providers can handle doing it: brownouts or blackouts.
What is a brownout?
While not as commonly known as a blackout, brownouts also play a less-noticeable role in load-shedding. A brownout is a partial power outage, while a blackout is a complete shutdown of electricity. Texas’ NEC Co-op Energy said that during a brownout, an electricity provider tries to throttle the flow of electricity in a certain area by 10%-25%. Brownouts get their name from flickering or dimming light bulbs seen as they happen, according to another electrical provider, Direct Energy.
Home appliances aren’t normally affected during a brownout, but the reduced electricity flow can damage sensitive electronics like computers and hard drives by undervolting them. It can even cause an electric motor to start running backward. Direct Energy said the best practice to keep electronics safe during a brownout is to unplug them from wall outlets. Brownouts also typically last a shorter time, as utility companies plan their start and end to mitigate spikes in electricity demand, according to NEC Co-op Energy.
In Columbus’ major outage, AEP appeared to rule out brownouts as an option.
“The storms damaged transmission equipment in eastern and southeastern Ohio,” AEP Ohio wrote. “Without those lines available to carry electricity, and with the high temperatures increasing the demand for electricity, the remaining power lines became overloaded. In order to prevent widespread damage, disconnecting customers was the only option.”
Blackouts: More than one kind
A blackout, or total loss of power, can last a few minutes, hours, or even days, according to NEC Co-op Energy. These are typically unplanned and caused by electricity usage that overloads the power, ice, or fallen trees on power equipment like transformers, or damaged power lines. In central Ohio’s case on Tuesday, it was a combination: storms damaging power lines and too few lines left working to keep up with electricity demand, according to AEP.
“A team of highly skilled and certified professionals monitor, control and analyze the power grid every second of every day,” AEP wrote. “They have to react to situations within seconds to protect the system. … Unfortunately, there simply was not enough time to notify customers before taking the necessary actions to protect the grid.”
The blackout that has plagued Columbus wasn’t planned. However, rolling blackouts — where an electric company rotates between cutting power to different areas and groups of customers for short periods — can be planned to help offset strain on the grid. AEP said that the situation leading to the June power outage also ruled rolling blackouts out as an option.
“In this case, the affected transmission lines cannot be brought back online until other lines that feed into the area are repaired from storm damage and returned to service,” AEP Ohio wrote. “This eliminates the ability to rotate outages from one area to another.”
To track power outages in the area, view AEP Ohio’s outage map below: