Pacific Gas & Electric's unusual decision to cut power to hundreds of thousands of customers in Northern California to reduce the risk of wildfires has angered many residents and lawmakers. Many of them questioned whether the company made the right decision.
About 600,000 Northern California customers, including some in the San Francisco Bay Area, were out of power on Thursday morning. Governor Gavin Newsom said on Wednesday the company's decision was "appropriate under the circumstances." But he also criticized the company for not investing enough in security and infrastructure upgrades.
The utility was found responsible for about two dozen forest fires and filed for bankruptcy protection in January. PG&E said it could face up to $ 30 billion in liability for fires started by its equipment in recent years.
Separately, Southern California Edison, the state's second largest utility company after PG&E, said on Thursday it reduced power to nearly 13,000 customers and that the closure could affect nearly 174,000 customers in nine counties, including Los Angeles. , Orange, Riverside and San Bernardino.
Why has the PG&E blackout affected so many customers?
PG&E said it acted after its meteorologists noticed a threat of high winds in up to 34 California counties. The National Weather Service has also issued a fire alert for these areas.
The utility uses blackouts when certain conditions are met. Sustained winds should reach at least 40 kilometers per hour with gusts of at least 45 m.p.h. Vegetation in and around its power lines must be dry and the humidity low. And the Meteorological Service must issue a "red flag" warning about the risks of forest fires.
High winds and dry conditions have been implicated in several California forest fires initiated by utility equipment. PG&E said one of its transmission lines probably started the state's largest fire, known as Camp Fire, which killed more than 80 people and destroyed the city of Paradise in November 2018.
How did the company decide which areas would lose electricity?
PG&E said weather forecasts were the most important consideration used to decide which areas would lose energy. But the company also turned off the power in some areas that may not experience adverse weather conditions. This is because the power lines that serve these areas are connected to lines and other equipment in places with high winds and dry conditions.
Critics of PG&E, including some state lawmakers, said the company may have deleted more customers than necessary to reduce the risk of fire. State Senator Jerry Hill, a Bay Area Democrat, has sent a letter venting his frustration to the California Utilities Commission, which will review PG&E actions.
"Today marks an unprecedented turnaround in the history of California's electricity service," Hill wrote. He said safety interruptions "should be a surgical measure of last resort."
Does this have anything to do with company bankruptcy?
Not directly. Power outages are part of PG&E's fire safety program, developed by the company in response to state rules established following the devastating 2017 fires in the Napa and Sonoma wine countries.
Lawmakers demanded that state utilities submit plans to help prevent fires. PG&E has proposed a number of measures, including turning off the power when the risk of fire was high. Another utility, San Diego Gas & Electric, has used this approach for years.
Safety measures were aimed at preventing fires and keeping businesses at risk by limiting their liability for damage caused by their equipment. In its bankruptcy case, PG&E has sought to resolve forest fire damage claims from thousands of homeowners, insurance companies and others.
How long will the blackout last?
National Meteorological Service PG&E internal models and forecasts indicate that extreme weather conditions may last until Friday. PG&E said it had restored the service to about 126,000 customers. But 600,000 were still without power on Thursday morning and thousands could still lose electricity.
Before restoring power, PG&E will have to inspect your equipment for damage and make necessary repairs. This process cannot begin until bad weather has passed, the company said.
PG&E uses 43 helicopters for aerial inspections, along with walkers. In some cases, the utility sends drones to help inspect the 24,782 miles of distribution lines and 2,443 miles of transmission lines.
PG&E can restore power quickly in some areas, while other places can be without electricity for days.
Do people with solar panels on the roof still have power?
Without a battery connected, a home's solar system usually won't work when the power grid goes black, according to Sunrun, the country's largest residential solar company.
Here's why: Roofing systems from companies like Sunrun, Tesla, and Vivint generally don't provide power directly to homes. The electricity generated from the panels goes to the electricity grid, controlled by the power companies and grid managers, and the customer is credited. As electricity flows to the nearest destination that needs it, it can travel back to the house that generated it or to a neighboring property. Otherwise, energy flows wherever the next nearest demand is, just as water follows the path of least resistance.
This configuration is in part a safety measure to ensure that electricity workers are not harmed by grid-connected home solar systems while working to restore power.
However, lithium-ion battery systems such as Tesla Powerwall or Sunrun Brightbox, which charge during the day, can keep homes powered by power outages, depending on the size of the unit. Increasingly, companies that sell solar panels also sell batteries to keep homes energized during power outages. Lithium-ion battery technology, recognized this week's Nobel Prize, is seen as a key to remodeling the power grid and home power.