By Scott Willis, Power
Since Juneau is not connected to a larger power grid, all the
electricity consumed in our community must be generated locally.
Over 98% of our power comes from renewable hydro
generation, most of which comes from the Snettisham
Hydroelectric Project. The rest of our hydropower is
generated at our Lake Dorothy, Annex Creek, Salmon Creek, and Gold Creek
But generating the
power is only part of the process.
The electricity then has to be delivered over
transmission lines to power substations around town, and then
distributed to the homes and businesses in the community.
What causes power
variety of problems can affect the power lines.
Anything that allows the electricity to find a path to
ground, or allows two wires to contact each other, such as a
tree or animal in the line, causes a “short circuit” or fault.
When this happens, large circuit breakers automatically
open the line to prevent the flow of dangerous or destructive
When these circuit breakers open, it interrupts the flow
of electricity to everyone beyond the fault.
If a fault happens on our main line from Snettisham, it
results in an area-wide outage.
If it happens on the line serving a single home, only
that home will be affected.
I've seen my lights
flicker. Why is that?
Sometimes you may see
the lights in your home dim or flicker momentarily.
This can be caused by a fault and breaker opening in
another part of the system, which briefly disturbs the
electrical flow throughout the system.
Can't you do anything
about power outages?
Many of our lines go
through very rugged terrain, or through heavily forested areas. AEL&P
works hard to prevent outages from occurring. We routinely
perform seasonal tree trimming, systematic equipment inspection
and replacement, transformer/breaker testing and infrared
imaging to identify potential problems before
they occur. In regards to tree trimming, we are authorized
to trim trees within our right of way. Quite often,
however, the trees that fall into our lines (as a result of
heavy wind or snow) originate outside of the right of way, which
makes them inaccessible during routine tree trimming.
Preventative measures aside,
the lines in our community will always be susceptible to
Mother Nature, wayward critters, and even people.
more than 16,000 customers with
electricity, 24/7, 365 days-a-year. The equipment that makes this happen works between 138,000
volts and 120 volts. Equipment wears out and -- when it does -- it lets us
know with an outage. Some equipment serves only a single home or
while other equipment serves the entire city.
People - 37%
People are only human.
Everyone is entitled to a mistake or two. The best examples of
man-made outages include vehicles running or backing into our equipment,
backhoes digging into cables, etc...
Mother nature - 24%
Weather is the big one. Heavy snow, ice storms and high winds will
always take their toll. Tree limbs that contact our lines will
always cause some sort of interruption. That's why we contract to
keep them trimmed. However, there are a lot of trees between here
and our Snettisham Hydro Facility.
Customers are encouraged to
protect sensitive electrical equipment
in their homes and businesses with surge suppressors, and may
want to consider Uninterruptible Power Supplies (UPS) for important equipment.
What should I do if
there is an outage?
If the power goes out
at your house, check to see if your neighbors have power.
If they do, then the outage is only affecting your home and we
won’t know about it until you call the number listed in the
If your neighbors are also without power, the outage is
probably large enough that we know about it already.
In that case there is no need to call unless you have
information about the specific location of the problem.
During large or lengthy outages we try to keep the community
informed through announcements on our local radio stations.
Listening to these with a battery-powered radio will keep
you informed about an outage.
Our crews respond to all
outages and continue working until power is restored to all of
Even though outages will always be a fact-of-life with
any electrical system, rest assured that we are doing our best
-- 24/7 -- to keep the lights on in Juneau.