Local News


Power outages explained: How one small thing can take out an entire grid

Posted at 5:16 PM, May 10, 2018
and last updated 2018-05-11 13:52:56-04

When one light goes out, they all go out - many people who have put up lights in their home have experienced this first hand. 

The same principle seems to apply to power grids across the country. Oftentimes something small can cause outages for thousands of people.

For example in Costa Mesa, California, 8,000 customers lost power after a raccoon got caught in a piece of electrical equipment. A similar scenario happened in Las Vegas on Tuesday when a bird was blamed for knocking out power for 4,000 customers in the valley, including Las Vegas police headquarters and University Medical Center.

To understand why minor incidents can have such a massive impact on the U.S. power grid, it's important to note the challenges that many of these systems face on a daily basis.

13 Action News reached out to the Federal Energy Regulatory Commission to learn about the types of stresses placed on a power grid, especially in extreme conditions like the blistering Las Vegas heat.

According to the FERC, when the temperature rises people tend to use more electricity, especially in the form of air conditioning. That puts a huge strain on the grid's ability to generate and transmit power to everyone that needs it, which may cause certain pieces of equipment to shut down.

When one part of the electric grid shuts down, more power may be transferred to other parts of the grid. That, in turn, adds more stress to the areas that were already overworked. This leads to a domino effect of more parts of the grid system shutting down.

The same principle applies when debris - or an animal - makes contact with an important piece of electrical equipment. Thus, one small problem can lead to a much bigger problem.

An extreme case of this happened in 2003 when a generating plant near Cleveland, Ohio went offline due to heat-related stress. The problem got worse as power lines began to sag because of the heat, which shut more parts of the grid down and put even more strain on the bits that were still active. The result led to power failures throughout Southeastern Canada and eight states in the U.S.

The FERC says that this blackout was cited as one of the reasons behind the creation of the Energy Policy Act of 2005. That act directed the FERC to approve mandatory reliability standards for maintaining service under various scenarios, such as the loss of a facility. 

Another organization - the North American Electric Reliability Corp. - develops and enforces standards so that grid systems can work under extreme stress. NV Energy says that to meet those standards, they have to make sure the Las Vegas grid system can withstand up to two major equipment failures.

NV Energy also says their crew inspects hundreds of parts of the grid system to make sure it's up to date. This type of work is primarily done during the "off-season," i.e. fall, winter, and spring.

"We have three months of extreme heat and nine months out of the year to prepare for it. Like Santa's workshop, we got to make toys all year for that one day," said Kevin Geraghty, Senior Vice President of Operations for NV Energy.

NV Energy says that it's rare for the heat to take out the power in the Las Vegas valley. Rather, it's random elements like cars crashing into power lines or debris flying into important pieces of electrical equipment that cause most outages.

So typical energy-saving strategies like keeping your lights off, unplugging your electronics, and easing up on the air conditioning can certainly help lighten the stress on the grid system. But it's also important to drive safe and keep items inside your home on those windy days in the valley.