|
The power line system works like your One of Great River Energy’s planning engineers provides an easy-to-understand description of how the transmission system works in the article below, which was printed in some of our member cooperatives’ newsletters in 2009. |
Power lines keep the cool coming on hot days
Heat waves immediately bring air conditioners to the minds of most people, but power lines and substations are what come to mind for people like David Kempf, electrical planning engineer for Great River Energy.
“These hot days are the kind of days we are preparing for when we look at the need to build a new power line or take an existing line and increase how much power it can handle,” said David Kempf of Great River Energy, wholesale power cooperative.
“Our transmission lines have to be large enough so when everyone turns up their air conditioner at the same time, the electricity keeps flowing and everyone can stay cool. These are the days people remember if they lose power,” he said.
Kempf said there is a misperception that the economic slowdown means new power line projects that were planned before the slowdown are no longer needed. “Most of the transmission system we have now was built decades ago -- before it was common to have multiple televisions in one home, before very large homes were common, and before the explosion of computers, cell phones and other electronics. We still have a lot of catching up to do from year after year of high growth in many parts of Great River Energy’s service area.”
Transmission lines are the large power lines that deliver large amounts of electricity around the electric system and from power plants.
Kempf said transmission systems operate similarly to a home’s fuse box or breaker panel. If you are using more electricity at once than the wires can handle, the breaker or fuse shuts off the power flow to that area to avoid damage. Transmission systems work much the same way. When the demand for energy gets too high for an area of the system, power flow shuts off to protect costly equipment. If there is no back-up source, there will be problems.
Outages, where electric service is interrupted completely, are a commonly understood risk of a vulnerable area on the electrical system.
Low-voltage is another risk. It can make the lights dim for every power user within the area of the weakness. More seriously, motors in home appliances such as air conditioners can be damaged. The motors compensate their power needs by drawing in more electric current, which creates more heat, sometimes to the point that they burn out. Uncorrected low voltage problems can ultimately lead to a blackout.
“We continuously analyze the system and make corrections to prevent low-voltage issues and outages. The system has to be reliable on high demand days. In areas that have seen a lot of growth, this often results in new transmission lines being needed,” Kempf said.
