PG&E last week answered critics wondering what it's doing about powerline-caused wildfires escalating in severity the past decade thanks to climate change.

The utility hosted a wildfire mitigation innovation event at its San Ramon conference center on June 22, much of which dealt with overhead powerlines -- one of the main culprits of wildfire ignition in recent years.

It introduced a plan to relocate 10,000 miles of overhead lines underground and showcased enhanced powerline shutoff systems, using new sensors to shut down a damaged line in contact with the ground or a foreign body in one-tenth of a second.

It also showed off next generation drones deployed throughout its system to inspect powerlines, remote grid systems for customers in rural areas prone to power shutdowns, and a new system of backup power for customers in those same areas working off medium-sized generators plugging directly into a building's utility box.

The most futuristic presentation involved PG&E's new partnership with San Francisco-based Burnbot, a company developing remotely-operated controlled-burn machines that can incinerate dangerous vegetation, extinguish it, and remove the fire emissions in one futuristic, slow-rolling machine.

"It takes the ancient practice of prescribed fire and brings it to the 21st century reality, where you've got structures intermixed with that vegetation, so you can't just put things on fire," said Burnbot Founder and CEO Anukool Lakhina, in the PG&E parking lot, standing before a bulldozer-sized machine.

"If you've got power lines around you ... we have a series of torches that burn in an enclosed chamber and as the machine moves, it also extinguishes any residual embers. The machinery also filters the smoke, so you have combustion happening in a completely controlled way with no risk of escape and no smoke and as a result.

"Now we can take prescribed fire and bring it to the wildland urban interface using good fire near power lines, near structures, near communities, and your sensitive habitats nearby that would have been challenging to do so."

Burnbot is undergoing tests the rest of this year before PG&E decides how to deploy the technology.

The utility took visitors across the street to its technology center to show off its enhanced power line safety system, which uses sensors to quickly cut power to a line once it contacts an object and starts arcing.

The test used a branch on two lines. Using the old way -- once power is turned on -- the branch smoked, sparks shot and the branch began burning, with a surge of power visibly arcing all the way down the line, which would presumably ignite material near the line in the real world. The process took about 10 seconds.

"That is the normal setting in the industry not just California," said Mark Quinlan, PG&E's senior vice president of wildfire and emergency operations.

With the new system, the line under the branch flashed once and power shut down almost immediately, without the elongated arcing down the line.

"After last year's full year performance, we saw a 68% reduction in ignitions and 99% reduction in the amount of acres impacted," Quinlan said. "That's incredible."

The utility also unveiled its new groundline distribution system, which entails undergrounding 10,000 miles of lines in its 44,000-mile system using ground level conduits, instead of spending more to dig deeper and tear up rock and the concrete and asphalt of streets.

The program started last year with 180 miles of cable brought down from above, where contact with trees and animals can start fires. It's on pace for 350 miles this year. PG&E officials said the process typically costs about $3.5 million per mile of cable going underground.

The new method -- which inserts the cable into a hard surface that typically can't be cut open with everyday tools (and withstands being run over by semi-trucks without damage) will cost about $1.5 million to $2 million per mile and be done 2-3 times faster. The boxes can be put a few inches into the ground, but without the typical fuss of digging trenches.

"The biggest issue with this is people are going to have to get used to it," said Brad Koelling, PG&E's senior manager of grid design. "Undergrounding is out of sight, out of mind for most people. This is going to be something that people are going to see."

The company's new backup power transfer meter looks like a regular power meter, only with a hookup that goes directly into a medium-sized generator. It also has a small utility panel with switches that, like a fusebox, controls what customers can turn on.

In most cases with a generator, the box can provide emergency power for one to two days.

The utility is also partnering with Richmond-based New Sun Road to deploy remote grid systems in areas frequently affected by wildfire-related power shutoffs, with the power coming from solar systems, batteries and backup generators. It's seen as not just an emergency option, but a year-round power provider that eliminates the need for powerlines and poles.

It's already been deployed in areas in Tehama and Mariposa counties and could be deployed in 30 more areas by 2026.

PG&E also showed off its next-gen drones by flying one over its courtyard. Partnering with San Mateo-based Skydio, the drones will augment the utility's manually operated drone inspectors to respond to sensor alerts around power lines in the field.

The new drones can also respond automatically to alerts from wildfire cameras to assess fire conditions. They can also use infrared technology to operate at night.