Electric utilities worldwide recognize that the weather has the single, greatest impact on operations.
In October 2007, nearly two dozen wildfires broke out in San Diego County. Hurricane-force, hot, dry Santa Ana winds, which are unique to Southern California, whipped the flames into an inferno and were largely responsible for the widespread damage.
At the time, SDG&E had access to data from only a handful of federally-owned weather stations, none of which was located in the windiest areas of our service territory. As a result, there was no way to know the true severity of the winds occurring in many of the backcountry communities we serve.
That was a turning point. Since those wildfires, no utility has focused more intently on gathering weather information than SDG&E.
We knew we had to get a clearer picture of where the strongest winds were blowing at all times and to develop a plan to manage Mother Nature. We needed better situational awareness.
To provide that crucial information, we brought in a team of meteorologists to map the areas with the highest winds.
Today, weather stations monitor every electrical circuit in SDG&E’s highest fire risk area, providing real-time readings of wind speed, humidity, and temperature every 10 minutes.
With 173 weather stations, our system is the largest and densest utility-owned weather network in America and all of the data is publicly available 24/7 to the National Weather Service, fire agencies, other emergency agencies and the public.
Today, our meteorologists develop daily forecasts and revise them based on the latest conditions. From an operations perspective, that data is vital.
Building on the success of the weather network, we created a unique historical dataset consisting of hourly weather and vegetation conditions across all of Southern California.
We identified where and when the threat of uncontrolled wildfires is the greatest. This “Fire Potential Index” converts environmental, statistical and scientific data into an easily understood, 7-day forecast of the short-term fire threat for the various geographical areas in SDG&E’s service area.
When the fire danger is extreme, we now know when and where to pre-stage crews to respond to possible outages or to de-energize power lines for public safety and prevent a fire.
In 2014, SDG&E collaborated with the U.S. Forest Service, UCLA and the National Weather Service to develop the “Santa Ana Wildfire Threat Index” for Southern California.
The index – a rating system similar to what is used to rank hurricane severity – lets the public know the severity of the fire potential associated with every Santa Ana wind event and what actions they should take to be safe.
The index was developed using 30 years of hourly weather and vegetation data amounting to billions of data points. These two key tools, SDG&E’s weather network and the wildfire threat index, have enabled the next step: translating all this data to understand and predict fire behavior.
We now are able to run computer-simulations of fire ignitions on our entire power grid to determine the circuits at highest-risk on any given day. With this computer model we can see, if a fire starts, how fast it will grow, how many acres may burn, and how many homes and power poles could be damaged or destroyed.
Our objective is to continue working with our partner agencies to develop what could be the ultimate “crystal ball” for predicting wildfires and their outcomes. The science is exciting, but even more important is the increased level of awareness that will help our communities to prepare and stay safe.
Dave Geier is San Diego Gas & Electric vice president of electric transmission and system engineering.