California fires
Seairth
Posts: 2,474
Between the fire risks and power outage risks, I hope everyone at Parallax stays safe and comes through without even a singe.
Comments
Ken Gracey
The powering down of the electricity network is an interesting idea. The power network is often to blame for sparking bushfires here in AU. Here is a lot of activity going on trying to detect and react quickly to faults, maybe they should just turn off for the worst periods
Small world, I live in Santa Rosa too and worked for HP for over 20+ years starting in 1980. HP was great place to work while Bill and Dave were still alive. Agilent/Keysight unfortunately lost a lot of the HP way. Hopefully the group/department your son works for still has enough of the HP way to give him and his family a good work/life balance. Glad to hear that your son & family and their home has escaped the latest round of fires. We were also lucky to not have to evacuate and be without power. A number of Keysight employees lost their homes in the 2017 fires and some of them got impacted again in these recent fires. Hopefully things will continue to improve around here...
My son just started work at Keysight a couple of months ago after finishing an EE degree at UC Davis. He already had a degree in music, but that wasn’t so practical when starting a family. I’m happy to think that his presentation of his project using the propeller helped land him the job, but he’s still learning the ropes, how to fit in. Indeed, it is cutting edge technology. This week of shutdown has to be a big hit for the company. The fierce Santa Ana winds are feared to pick up again tonight.
I’m currently in Kentucky, down from hiking in the Smokies/Appalachian trail. For fall colors. A completely different scene. We’re returning to the smoky Bay Area tomorrow though.
Prayers and good vibes for the area and those affected. This a life-changing event.
I’m rural, on the Texas coast, and at the very end of a very fragile grid. We’ve been through multiple hurricanes, floods, and even 48 inches of rain in a day. We spend more than a hundred hours a year on generator. We tease each other that we have a “disaster du jour”, but in our hearts we know that *nothing* compares with the awful physical and emotional effects of a fire. Nothing.
Be safe. And be wise. And perhaps going forward we might all hug our loved ones for just a little bit longer than usual. Because you never can know which hug may be the last, or which siren may be for you.
Indeed. It is all very disturbing.
But a map on the news today showed the area where Parallax is based, in a decidedly dry looking one.
Mascot reports very busy.
NO IT IS NOT.
It is a horrible idea.
PG&E cut down the work force clearing the power lines. To save money. Now a couple of years later the trees are do much growing near the lines and the solution is to simply switch off electricity to 200,000 people for a couple of days, because it is WINDY, really?
This is not a interesting idea, this is complete mismanagement on highest level.
Just think about it what it did to me and other affected people. No electricity, no Internet, no supermarkt, no gas station, no restaurant, no hardware store open in a radius of 150 miles.
Even IF you have a generator, you can't get gas for it. All freezers are thawing up, but you can just throw the food away, since you can't heat it, microwave don't work stoves don't work, no light, no heater, no shower because no water heater.
No way to buy food, no way to even get water, drinks, smokes, even flashlights or batteries or candles. Nothing.
People are dying here, not able to recharge their heart monitor systems, electrical wheelchairs stop working after 2 days, it is a complete mess.
Because PG&E did not want to pay people to clear the power lines. It worked fine for DECADES until they reduced the work force, and now 200,000+ people are out of electricity every 3 weeks for a couple of days because it is WINDY?
Really?
not happy at all,
Mike
Here's what they decided to do here after the devastating fires back in 2009. As you can see this part of the response totals $750m
https://www.energy.vic.gov.au/__data/assets/pdf_file/0020/41627/PBSP-overview-fact-sheet-2016-121216.pdf
I don't know what the predominant wiring is like in remote properties in northern CA, but here there has traditionally been a lot of Single wire earth return, which makes it hard to detect faults, and they're trying to move away from it fast.
And here's the project I came across the other week. What stunned me about it was the Analog to Digital converter speed they were using to detect the faults - 250 Msps.
http://blog.successful.com.au/swer-line-monitoring/
Here's hoping this wakes up the CA authorities
In regards to the fires, brush management is a big factor. My Dad lost his home and nearly all of his belongings in Yankee Hill during the Camp Fire (aka Paradise fire) last year. When I went up a month after to survey the property, it was eerie to see that nothing above 30 feet looked harmed in any way. Full green growth on trees, but down low, the manzanita burned so hot that the fire moved across the neighboring hills at an unreal pace and temperature. His aluminum boat was then a 30 foot long trail of molten metal down his driveway, yet the highest burn scar on the tree next to his garage was maybe 15 feet up. All but one of the trees on his property survived, but there was no brush at all left.
-Phil
You mentioned that prototype system SWER, sampled at 250 MHz. No technical details, but I guess SWER has something to do with measuring SWR on the transmission lines or some key into propagation delay that allows operators to localize breaks or arc-overs to specific poles and shut them down and respond quickly. The nice thing is that it seems that the system can be retrofitted.
The other article has to do with changing to less damage-prone, longer-lasting bundled transmission lines. Those would have a third wire, neutral, that could in effect be there for ground fault protection. What I don’t yet understand about that is how you can bundle the conductors and still carry the 10s of kilovolt that are necessary for lower currents and efficient use of copper.
I don’t think people understand the cost, technically, quite apart from the issues of mismanagement and other causes of fires, and their detection, suppression, planning, communication among agencies. And the terrific cost of the shutdowns.
I sat on the roof of my house during the 1991 Oakland hills fire, and watched as house after house went up in flames. It is nothing new in this state for sure, but, you know, there is that hot button issue, climate change. The oscillations trending slowly stronger.
One method is to use sulfur hexafluoride gas (SF6) as an insulator.
-Phil
You're right about the true cost aspects and unfortunately it takes a major disaster before the full costs are evaluated.
Here's the trial report covering an 18 month trial of 61 sensors located around 5km apart, its worth having a skim-read when you have some time. I think they're looking at Fourier transforming the full spectrum, rather than SWRs, and as far as I can tell they are passively monitoring from a 1.2m distance from the SWER power lines.
https://img1.wsimg.com/blobby/go/b578a722-35cf-4b12-b720-7d9489211e45/downloads/EFD SWER Trial Report.pdf?ver=1571127782086
(from the IND technology site)
Regarding cost the 12.7kV SWER cable is hard to beat, its just (too) simple. I think I saw a figure of 30,000 km of cable in the Vic network. That implies needing a network of 6,000 of these monitoring stations, 5km apart.
While the emphasis of the report is on detection, over time they will need to look at reducing false positives of these events. I note there is an electric fence signal picked up in amongst the kind of network faults you want to detect (section 9.1 of the report). Perhaps there's a need for a gps timebase locked electric fence controller, so they can easily eliminate that source from the data.
That may be a tough sell in California as SF6 is an extremely potent greenhouse gas.
https://ww2.arb.ca.gov/our-work/programs/elec-tandd
-Phil
Now in turn we can empathize with NSW and Queensland Australia. Tinder dry, drought, hot winds, evacuations, deaths.
https://www.npr.org/2019/11/08/777649636/wildfires-rage-in-australian-state-we-ve-simply-never-had-this-number-of-fires
Keep safe.
The article does not mention what is sparking the fires.
Thanks for the good long article about the technology there used to detect power line faults remotely. First I had to read the wiki about SWER (single wire earth return) transmission lines. The only place in the states that is used seems to be Alaska, across the tundra, where the ground rods have to be driven thoroughly down below the permafrost.
I think it takes some time before they determine the true cause of a given fire. In the past they have changed their view on what started a given fire. Best to give them time to investigate properly.
I was at a bbq with a guy who is the SES ("state emergency service") today. His pager was going off - they were looking for SES personnel willing to do 5 day firefighting tours interstate