Over the past decade, power grids have played roles in wildfires in multiple states, including California, Hawaii, Oregon and Minnesota. When wind speeds are high and humidity is low, electrical infrastructure such as aboveground power lines can blow into vegetation or spark against other components, starting a fire that high winds then spread. Under extreme conditions, utilities may opt to shut off power to parts of the grid in their service areas to reduce wildfire risk. These outages, known as public safety power shutoffs, have occurred mainly in California, where wildfires have become larger and more destructive in recent decades. On April 5-6, 2024, Colorado utility Xcel Energy carried out that state's first public safety power shutoff, cutting power to thousands of customers ahead of an intense windstorm. Public officials and Xcel customers complained that they had not received enough warning or explanation. Gov. Jared Polis has directed state regulators to investigate the incident and propose better procedures for the future. I am an electrical and computer engineer, and study efficient operation of power grids. I also live in Boulder County, where a wind-driven wildfire destroyed more than 1,000 homes in 2021. These shutoffs are likely to become more common in more places as climate-driven weather extremes stress aging grid components. This makes it important to understand and evaluate utilities' public safety shutoff plans. Shutting off power and turning it back on—in utility-speak, de-energizing and re-energizing—requires more than flipping a switch. The power grid is a complex system that maintains a balance in real time between electricity flowing in from generating plants and out to customers. Power lines don't have the capacity to store electricity for use later—it has to be used immediately. This makes the grid different from other critical infrastructure. Water networks can hold water in their... |