Tucson Electric Power Co. spent more than $5 million on storm-related emergency repairs this year through July - not including a major early-August storm that downed more than a dozen power poles on the south side.
By the time the monsoon clouds depart, TEP will likely reach the $6 million to $7 million range, the typical annual cost of storm repairs, a TEP spokesman said.
It's unclear whether this monsoon season will top 2011, when TEP saw the number of outages and their duration spike from the prior year.
In the first half of this year, the most recent figures available, TEP had 673 "sustained outages" - shutdowns lasting more than five minutes, with a single cause. That's a pace of more than 1,300 annual outages, but that doesn't include much of the still-raging monsoon season.
Last year, TEP reported 1,988 sustained outages and the number of outages per 100 customers jumped to nearly 1.4 from just over 1 in 2010. And the average outage lasted 112 minutes - about 26 minutes longer than in 2010 and about 20 minutes longer than the prior five-year average.
While it may be little comfort to TEP customers who have suffered lengthy outages, TEP fares pretty well on outages compared with utilities nationwide.
In responding to outages, TEP ranks in the first quartile - the top 25 percent - for outage duration in 2010 and 2011, in a survey by the Edison Electric Institute.
It did slip in rankings for outage frequency last year, however.
TEP ranked in the third quartile for outages per customer last year, down from the second quartile in 2010.
Those results, based on criteria set by the Institute of Electrical and Electronic Engineers, exclude so-called "major event days" when the likelihood of storm damage is high.
Nearing the end of a rate freeze in place since late 2008, TEP recently filed to increase rates by 15 percent, citing slipping revenues and slow customer growth since the recession.
TEP has said that it needs higher rates partly to keep up with system reliability improvements, but service quality has not been compromised, TEP spokesman Joe Barrios said.
"There's been some deferral of planned projects, but if there was anything we felt had to be done, we did it," Barrios said.
"It's like you see a street that needs repair - maybe there's the beginning of a crack or chuckhole - so you can put off repairs for a period of time, but eventually you'll need to patch it or resurface the roadway."
And though the outage-frequency ratings exclude major storm days, last year's tally included a damaging storm - a microburst that downed power poles along West Ina Road - that wasn't counted as a major-event day partly because TEP was able to restore service relatively quickly, Barrios said.
Besides emergency repairs, reliability improvements like upgrading power poles from wood to metal or adding line capacity are an ongoing part of TEP's planning process to avert future outages and make it faster to restore service.
One example, Barrios said, is a current project to install thicker, higher-capacity power lines on West Congress Street near Interstate 10. Crews working on that project had to stop last week to help restore service lost from an Aug. 5 storm that knocked down 15 power poles along South Alvernon Way between East Benson Highway and East Valencia Road, Barrios said.
Another example is replacing wooden power poles with sturdier metal ones. A metal power pole that carries a 46,000-volt power line - typically carrying power from high-voltage transmission lines to neighborhood distribution lines - costs from $5,000 to $6,500, or about 5 percent to 10 percent more than a similarly sized wooden pole.
Metal poles cost more but have lower lifetime costs, Barrios said, adding that the company considers the cost and benefits of metal replacement on a case-by-case basis wherever repairs are needed or improvements are considered.
To spread the costs and benefits of metal, TEP in some areas installs metal poles - called "stoppers" - periodically between stretches of wooden poles, Barrios said.
"Stopper poles help to minimize the damage and help us restore service more quickly. … (They) help avoid a domino effect," he said.
One current example can be seen along West Orange Grove Road east of North Thornydale Road, where TEP is installing metal stoppers every few poles as it moves power lines to make way for street widening.
Tucson Electric Power Co. saw its outages per customer and average outage time jump in 2011 due to a busy storm season.
2005 2006 2007 2008 2009 2010 2011
Outages per customer 0.87 1.17 1.80 1.17 0.88 1.04 1.39
Average length of outages (in minutes) 89.6 90.6 99.5 100.8 82.1 85.9 112.2
Pesky LIttle outages
• Often there are brief outages caused by wind or tree branches that trip circuit breakers but are automatically fixed by so-called "reclosers."
• TEP relies to some degree on customers to call about outages, but the company often doesn't hear anything about the brief outages that are automatically fixed.
• Customers plagued by intermittent brief outages can ask to have their meters "charted" by the company, which involves attaching a device that records power levels and outages over time. This can help the utility pinpoint problems in the neighborhood.
• TEP has crews that go around and look for issues with trees getting involved in power lines; the company also relies on customers to let them know about such hazards.
Contact Assistant Business Editor David Wichner at email@example.com or 573-4181.