California’s Preventive Power Cuts To Stop Spread Of Wildfires

California pre-emptively cuts power to millions of people to try and prevent the spread of devastating wildfires.

October 2019 saw the forecast of wildfires with the potential to cause similar death and destruction to the ones seen in California the previous two years, which were the deadliest and most damaging on record.

High autumn winds can knock down electricity pylons or power lines, or blow trees and other vegetation into contact with them. Combine this with California’s traditionally dry conditions and it’s a recipe for disaster.

To reduce the risk of repeating prior incidents where damaged power lines and other electrical equipment were the catalyst for destructive blazes, utilities including the Pacific Gas and Electric Company (PG&E) deliberately cut power as a preventive measure.

During the 2019 wildfire season, more than 1 customers – totalling more than 3 million people – had their supplies interrupted in such a way.

Shutting Down Power For Safety Reasons

So-called Public Safety Power Shutoff (PSPS) has been standard practice across much of California for years. Historically they’ve been implemented in rural areas, but as the state’s population has spread to areas that were formerly wilderness, PSPS is commonplace in such locations too.

The shutdowns aren’t just limited to the most fire-prone areas as utilities have to close entire distribution and transmission lines across much wider parts of the state.

PG&E has incorporated PSPS – also known as de-energisation – into its core strategy since 2018.

Even though its 2019 Wildfire Safety Plan included ramping up previously-neglected infrastructure maintenance procedures, PG&E’s primary response is shutting down its grid in dry and windy weather.

Depending on the fire risk at the time, PG&E’s plans demand the shutdown of up to 30,700 miles of transmission and distribution lines. This is approximately a quarter of California’s grid and could potentially impact all 5.4 million customers using the utility (roughly 16 million people in total).

As well as the safety aspect, there’s another reason why grid operators such as PG&E proactively turn off the power at times of risk.

Under California’s unique legal interpretation of Inverse Condemnation, utilities companies are liable for any damage to private property, even if they comply with all state energy-related rules and regulations.

The wildfires of 2017 and 2018 incurred PG&E liabilities of $30 billion, which forced the company into filing for bankruptcy.

The utility eventually agreed a $13.5 billion settlement with victims in December 2019, which should enable it to emerge from insolvency. This followed earlier agreements with insurers and local authorities.

Timeline Of The Preventive Power Cuts

PG&E announced widespread power shutdowns on Tuesday 8 October to begin the following day and last for several days. The move would cut power to more than 800,000 customers across 34 counties in northern and central California, the largest preventive outage in state history.

A day later, another utility company – Southern California Edison (SCE) – followed PG&E’s example and cut supplies to 13,000 customers, as well as issuing a warning that a further 100,000 people across eight counties may face similar circumstances.

Winds began to subside three days into the shutdown, enabling PG&E to restore supplies to roughly a third of customers. However, 500,000 users were still without electricity.

A further round of cuts came a couple of weeks later. On 25 October, San Diego Gas and Electric cut power to 19,000 homes across San Diego County, with the potential to extend the shutdown to 50,000 properties.

Over the weekend of 26-27 October, PG&E’s second major Public Safety Power Shutoff came into effect, affecting 940,000 customers.

On Monday 28 October, thousands of Los Angeles residents in the wealthy suburb of Brentwood were evacuated because of a fast-moving wildfire.

Amongst those forced to flee were NBA great Lebron James and the former state governor, actor Arnold Schwarzenegger.

With high winds forecast, the power outage continued into the Tuesday and Wednesday. In total, more than 1 million customers (3 million individuals) were affected.

Another shutoff was required on Wednesday 20 November, with up to 150,000 users in 10 northern California counties left without electricity.

Pointing The Finger

The shutdowns instigated a widespread backlash from California residents. Frustrations centred on a lack of information about when people’s power would be cut.

State Governor Gavin Newsom was “outraged because it didn’t have to happen”.

“They’re (PG&E) in bankruptcy due to their terrible management going back decades. They’ve created these conditions, it was unnecessary.

“This can’t be the new normal.”

– California Governor Gavin Newsom

The Governor also warned that the state could take over PG&E if the utility didn’t turn its situation around by the middle of next year.

“If Pacific Gas and Electric is unable to secure its own fate and future… then the state will prepare itself as backup for a scenario where we do that job for them,” he acknowledged.

Looking To The Future – Any Solutions In Sight?

The fire risk from California’s electricity supply is mainly due to the large amount of power running above the ground in transmission and distribution lines.

Across the state there are approximately 26,000 miles of high-voltage transmission lines, plus another 240,000 miles of distribution lines carrying electricity to homes and businesses.

PG&E manages roughly 107,000 miles of the distribution lines. Three-quarters of these (81,000 miles) are overhead.

Would it be an option to convert some, if not all, of these to underground lines?

Technically, it could be done, but the cost would be absolutely astronomical.

For high voltage transmission lines, the estimated conversion cost is $80 million per mile. Underground distribution lines would cost about $3 million per mile compared to the $800,000 per mile price tag for overhead lines.

Upgrading all overhead distribution lines to underground would cost upwards of $240 billion dollars. That’s the equivalent of $15,000 per PG&E customer.

That’s before we take into account replacing the more expensive electricity transmission lines.

Micro grids are another suggested solution. These distributed energy networks would reduce the reliance on lengthy transmission and distribution lines.

During the recent rounds of PBPS, four towns in northern California managed to – partially – keep the lights on. Angwin, Calistoga, Placerville and Grass Valley were part of PG&E’s efforts to trial temporary “resilience zones” in areas that are particularly prone to fire-related outages.

The utility deployed 23 MW of temporary generation to power nearly 5,000 customers in total, including fire stations, hospitals, and the business district.

It has issued a request for offers to provide distributed generation during future safety-related power outages. While it has also submitted plans for up to 300 MW of temporary generation to be in place for the 2020 wildfire season.

One potential stumbling block with PG&E’s microgrid efforts so far is that is has relied exclusively on diesel power, which does little to help California’s commitment to move to cleaner energy sources.

PG&E’s Paul Doherty told the Utility Dive news website that it was looking at alternatives: “If it’s natural gas, if it’s something else, that would be the preference to diesel generation”.

Ultimately, he wants to see solar, battery storage and other clean tech powering the micro grids of the future. But the utility would have to install vast arrays of solar panels to substitute the electricity demand during future shutoffs.

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