Wildfire pushing California to brink of blackouts

SAN FRANCISCO • A wildfire raging uncontrollably across southern Oregon has knocked out three electrical lines so critical to the stability of grids in the western US that California has warned of rotating blackouts and Nevada faced a power emergency.

The fast-moving Bootleg fire has crippled a key transmission system known as the California Oregon Intertie that the Golden State has depended on for years for electricity imports.

The takedown of the intertie has had a knock-on effect on another key import hub, known as the Pacific DC Intertie, that brings in electricity from the Pacific Northwest, California's grid operator said in a media briefing on Saturday. In all, California has lost 5,500MW of power-import capacity - enough to light up roughly 4.13 million homes.

The fact that a single wildfire has brought America's most populous and affluent state to the brink of blackouts is among the most powerful demonstrations yet of how vulnerable the world's power grids have become to the effects of climate change.

Extreme heat, drought and dry conditions globally have shrunk hydropower reserves, driven up electricity demand to record levels and touched off some of the worst wildfire seasons in modern history.

Last August, California suffered its first rolling blackouts since the US West energy crisis two decades ago because of extremely hot weather.

And in a foreshadowing of what was to come, days before this year's summer officially began, high temperatures forced the California ISO to make an unusually early call for conservation, allowing the region to duck another round of rotating outages.

California was not the only state facing power woes last Friday evening. Nevada's power system was among those in the region that also faced emergency levels, said Mr Mark Rothleder, California's ISO's chief operating officer.

On top of managing California's grid, the agency serves as a reliability coordinator and is responsible for monitoring conditions across the western region.

Nevada utility NV Energy said it was not forced to resort to blackouts, but the company was calling for customers to conserve over the weekend.

Exactly when the Bootleg fire would subside enough to re-energise the California Oregon Intertie remains to be seen.

Megawatts of power-import capacity that California has lost - enough to light up roughly 4.13 million homes.

The Bootleg fire had burned through 31,119ha of southern Oregon and zero per cent of it was contained as at Saturday afternoon, forcing evacuations in Klamath County and shutting sections of a national forest, according to an update from the US Fire Service.

Meanwhile, the agency said, it has no timeline available for the restart of the intertie lines.

Temperatures across California were forecast to remain high into yesterday, with Sacramento set to reach 42 deg C before cooling down slightly today.

The extreme temperatures that scorched the Pacific Northwest late last month led to nearly 200 deaths in Oregon and Washington, as people struggled to keep cool in poorly air-conditioned homes, on the street, and in fields and warehouses.

The same "heat dome" effect that enveloped the Northwest - in which hot, dry ground traps heat and accelerates rising temperatures - has descended on California and parts of the Southwest this past weekend.

The record-shattering temperatures in the Pacific Northwest the week before would have been all but impossible without climate change, according to researchers.

Because climate change has raised baseline temperatures about 1 deg C on average since 1900, heatwaves are likely to be hotter and deadlier than those in past centuries, scientists said.

Excessive-heat warnings blanket most of California, along with parts of Nevada, Arizona, Utah, Oregon and Idaho.

BLOOMBERG, NYTIMES