Featured Research

from universities, journals, and other organizations

Why does hot weather cause power outages?

Date:
July 19, 2013
Source:
Lewis University
Summary:
Why is the power grid so sensitive to high temperatures? It's quite simple really. First, we certainly love our air conditioners, and air conditioners demand a lot of power. Second, power is generated at only a few places in the country, and yet our air-conditioned homes and businesses and factories are everywhere.

Why is the power grid so sensitive to high temperatures? It's quite simple really. First, we certainly love our air conditioners, and air conditioners demand a lot of power. Second, power is generated at only a few places in the country, and yet our air-conditioned homes and businesses and factories are everywhere.

Transmission lines have to carry power from these relatively few power injection points to all these different destinations. Transmission lines, however, are just wires, and they have limited capacity. In fact, their capacity actually goes down when it's hot. This is worsened by the fact that, when a transmission line is carrying a lot of power, it heats up. The metal conductor in the line expands, causing the line to droop. If the line droops too much, it makes contact with foliage on the ground, resulting in a short circuit and an end to that line's ability to carry power. With that line now out of service, other lines have to pick up the slack, but they, too, become overloaded and prone to the same problem. Furthermore, as the amount of power these lines carry grows, so does the amount of power lost through them due to heat, as well as the amount of "magnetic loss," which we call reactive power.

As reactive power is expended at a fast clip on these heavily loaded lines, it can no longer do what it is intended to do, which is to keep our voltages at their designed level. As the amount of reactive power falls, so do voltages. When the voltages fall below what they're supposed to be, the lights in our home dim, our appliances run at speeds that cause wear and tear on their motors, and our air conditioners begin to pose an even greater burden on the system.

In other words, there are some rather nasty feedback mechanisms that take place that cause the grid a lot of stress when we all turn our air conditioners on. Power system operators traditionally have had a very limited number of controls to counteract these bad behaviors.

Fortunately, the Smart Grid is giving operators a lot more opportunities to keep a weakened grid from falling apart. The Smart Grid is a national effort to modernize the electrical grid by adding lots of automatic, computerized controls to it. Some of these controls can actually communicate with each other autonomously, making decisions in real time without operator intervention. Some of the controls can actually be used to throttle individual customers' energy use (provided they've contractually agreed to participate in such an action) to reduce demand in one area so that other areas can remain safe. Other controls help add renewable sources such as wind and solar power to more traditional electrical sources like coal and natural gas and nuclear.

Local solar and wind capacity can be used to provide some of the demands of a region, reducing the load on the broader grid. Finally, devices called synchrophasor measurement units give operators who work to ensure that the entire grid remains intact up-to-the-microsecond, GPS-synchronized data about what's happening on the grid over hundreds of miles. That big-picture perspective gives operators and the automated equipment they depend an unprecedented view of emerging problems before they spread.


Story Source:

The above story is based on materials provided by Lewis University. Note: Materials may be edited for content and length.


Cite This Page:

Lewis University. "Why does hot weather cause power outages?." ScienceDaily. ScienceDaily, 19 July 2013. <www.sciencedaily.com/releases/2013/07/130719103146.htm>.
Lewis University. (2013, July 19). Why does hot weather cause power outages?. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/2013/07/130719103146.htm
Lewis University. "Why does hot weather cause power outages?." ScienceDaily. www.sciencedaily.com/releases/2013/07/130719103146.htm (accessed August 23, 2014).

Share This




More Matter & Energy News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Is It a Plane? No, It's a Hoverbike

Is It a Plane? No, It's a Hoverbike

Reuters - Business Video Online (Aug. 22, 2014) UK-based Malloy Aeronautics is preparing to test a manned quadcopter capable of out-manouvering a helicopter and presenting a new paradigm for aerial vehicles. A 1/3-sized scale model is already gaining popularity with drone enthusiasts around the world, with the full-sized manned model expected to take flight in the near future. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Coal Gas Boom in China Holds Climate Risks

Coal Gas Boom in China Holds Climate Risks

AP (Aug. 22, 2014) China's energy revolution could do more harm than good for the environment, despite the country's commitment to reducing pollution and curbing its carbon emissions. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Former TSA X-Ray Scanners Easily Tricked To Miss Weapons

Former TSA X-Ray Scanners Easily Tricked To Miss Weapons

Newsy (Aug. 21, 2014) Researchers found the scanners could be duped simply by placing a weapon off to the side of the body or encasing it under a plastic shield. Video provided by Newsy
Powered by NewsLook.com
Flower Power! Dandelions Make Car Tires?

Flower Power! Dandelions Make Car Tires?

Reuters - Business Video Online (Aug. 20, 2014) Forget rolling on rubber, could car drivers soon be traveling on tires made from dandelions? Teams of scientists are racing to breed a type of the yellow flower whose taproot has a milky fluid with tire-grade rubber particles in it. As Joanna Partridge reports, global tire makers are investing millions in research into a new tire source. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins