When the lights go out
Brick Rule, PE
Florida Power & Light 162 Morgan Lane Pt Charlotte
Fl 33952 (941) 423-4809
brick_rule@fpl.com
Abstract
This paper discussed the use of Geographic Information Systems (GIS) for disaster
recovery at Florida Power & Light. Extensive wind loss modeling is used to produce
detailed estimates of expected losses. These models have been useful in evaluating the
total potential risk and in developing specific response plans for individual storms. GIS
is used to quickly re-divide the new workload into manageable portions and to locate
suitable sites for temporary work headquarters. Extensive GPS satellite-positioning data
is collected after the storm passes to provide re-validation of the estimated damage as
well as recalibration of the damage models. GIS systems have great, largely untapped
potential to communicate specific recovery information between all agencies involved in
a recovery effort.
Background
Florida Power & Light Company is among the largest and fastest growing electric utility
utilities in the United States serving nearly 4 million customers in about half the state of
Florida. Power is delivered safely and reliably from 86 generating units through more
than 70,000 miles of overhead and underground lines. Geographic Information Systems contain precise
location data on 1.4 million poles. FPL has added more than 800,000 customer accounts since 1990. In
2001 alone, FPL added nearly 87,000 new accounts. In the past 10 years the reliability of electric service
has improved owing in part to the extensive use of systems that analyze customer outage reports and
predict the right location to send the appropriate people to effect the necessary repairs.
Perhaps there is no area in the country that is more vulnerable to the destructive power of a hurricane
than the crowded coastlines of Florida. Within a few
miles one can find very rural and sparsely populated
areas as well as dense urban development and
everything in between. The impact of any landfalling storm largely depends on the
geography of where it hits. The affected areas will require large increases in personnel in
a very short time to handle the restoration. Often this means increasing field personnel
from 50 to 2500 in 1 day. Existing work locations are never large enough to handle this
increase in workers and heavy equipment and so GIS plays an important role in rapidly
planning and providing for the deployment.
Where geography is an important consideration, Geographic Information Systems are
vital. At FPL Geographic Information Systems are critical to maintaining the kind of
service reliability that our customers have come to expect.
Anticipating the amount of damage
Forecasted Winds The Tropical Prediction Center, also known as the National
Hurricane Center will issue storm position and track forecasts every 6 hours as a storm
progresses. These advisories contain latitude and longitude coordinates, maximum winds
and the radius of hurricane force, tropical storm force and gale force winds in each
quadrant. The expected winds and time of occurrence can be calculated by interpolating
the maximum wind speed between position fixes and at radial distances from the center
of circulation. Naturally, these expectations must be recalculated as each new forecast is
received. Using this data, FPL forecasts the wind at important locations, radio towers, power
plants and company buildings. The forecast is also made for each square mile of the
service territory. It is this high-resolution wind field data that is used to drive the
damage estimates that will define the restoration effort.
Calculating Damage Losses from a hurricane are a function of storm strength, size and
the locations involved. A larger storm with lower wind speeds may well cause greater
damage than a small more powerful storm. At FPL, loss experience curves developed
following Hurricane Andrew and other outage models are then applied to facility counts and
wind speed in each square mile of the service territory. The resulting estimate is then
summarized into 800 predefined zones, each of which is bounded by natural or political
features. When grouped together these predefined zones will form larger areas with
common sense boundaries and allow for the re-division of the normal work area
assignments.
The Federal Emergency Management Agency (FEMA) has developed a similar free GIS
based loss estimation system used for buildings known as HAZUS. Using this system
with its many construction specific loss curves and appropriate inventories of the building
stock, authorities can evaluate risk, design effective mitigation strategies and quickly
estimate the effect of a specific storm.
Expected position, radius of winds and wind speed are all subject to change until the
storm actually passes. Damage estimates of course change with each new forecast. But
commitments must be made for additional personnel, housing and food prior to landfall
when there is still considerable error in the forecasted track. Because of this a suite of
scenarios is usually created varying both track and wind speed in order to develop the
range of possibilities. The resulting plan is then put into motion well before the storm
makes landfall. Hotel rooms are secured, meals are ordered and people are moved from
neighboring utilities all over the southeastern United States in preparation for the effort.
Staffing the Response
Divide and Conquer Typically 5000 – 7000 additional workers will need to be brought
in to handle the restoration. These new resources and all their heavy equipment will
never fit into an existing work center and so new staging sites must be set up. Contracts
have been made in advance with over 100 large facilities such as shopping malls or
racetracks. These facilities can be used as temporary headquarters for the large number
of people and the equipment that will be needed. The estimated workload has previously
been divided into 800 common sense bounded zones that can be regrouped into larger common
sense areas. Each new area will contain one or more of the possible new work locations and each of
these can accommodate a different number of people. There is a limit of the total number of work
locations that can be supported and the problem is now to provide a plan that divides the workload that
has yet to be discovered and provides for the people that will arrive while minimizing the
restoration time for all areas.
Standard Boundaries are tried first. Service center staffing increases with damage and
with decreasing restoration days. Staffing is limited to the space available in each service
center and the number of Staging Sites possible is limited.
The importance of this process can be best illustrated in the example below. Here the
normal division of work areas would have required far more people in three locations
than could be supported.
In addition, much of the new capacity added would not be utilized and in the end work or workers would shift from
one location to another creating more inefficiency.
