POWER THAW
Why is it taking so long to get the lights back on?
Some Oklahomans are experiencing their fifth day in the dark. Others are in their second, third or fourth.
Current estimates show it could be another seven days before power fully is restored across Oklahoma Gas and Electric Co.'s service territory in central and northwestern Oklahoma.
Naturally, affected customers are already asking (and in some cases demanding) to know why it is taking so damn long.
In this case, there's a couple of reasons: The complexity of the system used to get power from where it is made to where it is consumed and the storm's characteristics.
The journey begins
Electricity just doesn't magically arrive at your house to power your lights, charge your phones or energize your bigscreen TV, laptop or gaming
system.
It has to get from the point where it is generated to where it is consumed.
Think of it like this: Mountains have to get snow, and sunshine has to warm the snow to cause it to melt. Then, the water has to have a way to get from the mountain peaks to valley lakes where it can be used.
Getting electricity from where it is made to where it is consumed works in a similar fashion.
First, it has to be created.
In Oklahoma and across the Great Plains, much of it is generated by turbines that makeup nu merousw ind farms, but a significant amount also is created by generating stations fueled by natural gas. Other sources include coal-fired generating stations and other renewable sources such as solar farms and water-fueled generators in dams.
The electricity created by all those sources are dispatched daily onto a regional power grid overseen by the Southwest Power Pool ( SPP) t hat covers a 552,000- squaremile area covering Oklahoma and all or parts of 13 other states between the Red River and the U.S .- Canadian border. The grid provides the energy across a network of more than 60,000 miles of high-voltage, direct current transmission lines.
On a daily basis, the SPP estimates expected shortterm power consumption needs from members including utilities, cooperatives and other major consumers who take power from the grid.
The SPP oversees a dayahead market process that meets those needs using the most reliable, affordable energy available from power generators that feed its grid.
Its work ensures supply meets demands and helps to keep costs affordable for end users — that's you and me, the consumers.
Using the snow analogy, it has fallen in the mountains and melted. So far, so good.
Bringing it home
Herein Oklahoma, regulated utilities and electrical cooperatives cover specific service territories. They all pull power from the SPP grid and deliver it to substations, which step down the voltage of the power that eventually makes it to our homes.
The energy is provided to consumers using a distribution system that, in most areas, consists of poles that support elevated lines. Using the snow analogy, it works like rivers that carry the water from origin melting points to lakes in the valleys below.
Larger lines, carried by poles that often are made of steel, carry the energy to regional consumption zones (like a portion of a community or county). Once there, it is further distributed into specific neighborhoods using a network of lines usually carried by wooden poles next to streets or sometimes on property lines that separate one home or business from another.
Transformers used throughout the distribution system systematically reduce the amounts of energy carried through specific lines to avoid creating overload problems for end users throughout the distribution area.
Each consumer is connected to the distribution system through a service drop line, which delivers the electricity from the localized network to a“meter base” so that electricity flows through a home' s or business' wiring.
Oklahoma Gas and Electric Company, a regulated utility that serves about 790,000 customers who are in the state's central region from border to border and a good chunk of northwestern and eastern Oklahoma to boot, owns, operates and maintains a distribution system consisting of about 29,400 miles.
With the type of storm Oklahomans experienced this week, that matters, given that thousands of miles of distribution lines were impacted.
Storm timing, severity key
This year's ice event is reminiscent of one that hit the Oklahoma City area in 2007. That storm, which hit in December, left 237,241 of OG& E's customers in the dark at its peak.
At the time, au tili ty spokesman said the number of customers left powerless by that storm was the largest the utility had ever seen.
This time, more than 400,000 customers were affected at one point or another, through Friday. Why?
First, the storm arrived before nearly all the trees in the region had shed any leaves. That gave the ice that fell over a 72- hour period much more surface to stick to, dramatically increasing weight loads
trees had to bear.
Those heavy loads caused trees to lean ( or, in cases where limbs broke, fall) into distribution lines, causing them to become grounded and prompting fuses to blow and transformers to fail.
Second, the storm was as low mover that basically inflicted its wrath over a three-day period, with particularly strong winds t hat aren't normally experienced during icing events. At least some customers who had their power restored once or more times ultimately were left in the dark again.
Once t hawing began, trees began to re gain their resiliency. However, numerous limbs were left entangled in the system's distribution lines.
The utility must remove the left-behind debris, inspect the distribution system' s poles, cross arms, transformers and electrical lines and make needed repairs before power can be restored.
Finally, customers must —utility officials emphasized this—make sure their meter bases can take power before OG&E will restore power to a specific home or business.
Thousands deployed
Dallas Rowley, OG&E's incident commander for t his storm, said Friday that more than 3,300 independent contractors, workers from utilities providing mutual assistance, and OG&E personnel were working in the field to make needed assessments and repairs so that power could be restored.
The utility brought in workers from Texas, Missouri, Ohio, Kentucky, Mississippi, Alabama, Georgia, Tennessee, Louisiana, Arkansas, Kansas, Indiana, Iowa, Wisconsin, Illinois, Nebraska and Colorado to help, Rowley said.
He added that he expects thousands of customers will be restored daily, with full restoration achievable by next Friday.
“We always see tree damage in ice storms, but not at this level, and that has delayed some of the restoration. That is what makes this i ce storm so difficult, because we are having to remove the trees before we can even see what kinds of damage happened. We have got to evaluate transmission and then distribution systems — go down that river — and make needed repairs before we can deliver power to a specific customer.
“And with t he moisture we got through the storm, we' re having problems getting to certain locations.”