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California power grid, wildfires
17

California power grid, wildfires

California power grid, wildfires

(OP)
So, among our various issues in California, we have an aging electric grid.
It may be more an economic /political issue than engineering?

https://www.wsj.com/articles/pg-e-knew-for-years-i...
https://www.nytimes.com/2019/02/28/business/energy...

Even in spite of massive intentional blackouts, it seems that one or more of our recent/current fires were caused by power lines.

Of course, people don't like wide cleared areas along power lines, but maybe that would be a big starting point.

Thoughts?

Jay Maechtlen
http://www.laserpubs.com/techcomm

RE: California power grid, wildfires

Some people don't like a lot of things that would be beneficial to them. It is more political than economic. California is still wealthy, although many of its citizens and cities are not.

RE: California power grid, wildfires

Everyone complains when taxes get raised and everyone complains when the government doesn't have the funding to do things it should do.

RE: California power grid, wildfires

Quote:

government doesn't have the funding

And yet, the power companies are more than happy to charge us millipennies per mile for delivery of the same electricity that they now withhold from us, because those micropennies went into profit, rather than actual maintenance.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: California power grid, wildfires

But otherwise stock prices wouldn't go up as quickly (/s)

RE: California power grid, wildfires

Saw this quote somewhere:
It costs about $3 million per mile to convert underground electric distribution lines from overhead, while the cost to build a mile of new overhead line is less than a third of that, at approximately $800,000 per mile, according to a section on PG&E’s website called Facts About Undergrounding Power Lines.

California has 25,526 miles of higher voltage transmission lines, and 239,557 miles of distribution lines, two-thirds of which are overhead, according to CPUC. Less than 100 miles per year are transitioned underground, meaning it would take more than 1,000 years to underground all the lines at the current rate.

RE: California power grid, wildfires

2

Quote (RVAmeche)

Everyone complains when taxes get raised and everyone complains when the government doesn't have the funding to do things it should do.

This conversation always reminds of this scene.

Edit: Probably should add something slightly more beneficial to the conversation. This summer they applied a wrap and coating to the bottom 8' of wooden H-frames in my neighborhood (Colorado Rockies). I'm not sure if that will actually help since flames can get a lot higher than 8'. I wonder the cost difference steel monopoles vs putting lines underground? Especially since all of the lines burnt down last year were replaced with more wooden H-frames...

RE: California power grid, wildfires

Quote:

Less than 100 miles per year are transitioned underground
so barely $300 million was spent, but they consistently made "available" to stockholders over $1 billion per year, except for the massive loss allocated for the fire from last year.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: California power grid, wildfires

That's capitalism, American style.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: California power grid, wildfires

It is not going to be easy to put transmission lines underground in the rock of the hills and sharp valleys where the most difficult fires start.

And no, California would not allow the necessary clear-to-rock and continuous application of vegetation killing chemicals over a minimum 300 feet on each side of the transmission lines necessary to ensure that a line drop could not deflect in a high wind far enough to reach flammable material; nor would they appreciate the sudden runoff of mud into local streams and rivers nor mudslides onto roads where there was no longer plant material to retain the soil.

If they did, then every millionaire homeowner in LA on those angle-of-repose fire target hills would have cleared them to dirt as a fire-break a long time ago, and then watched their properties subside with the next heavy rain and head into the surround canyons.

RE: California power grid, wildfires

One of the reasons why we chose to live down on flat land far from any untended brush or forest land.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: California power grid, wildfires

Replacing the bare overhead conductors with insulated ones should reduce the wild fires at the same time not costing a fortune to do the work. Why is that not an option!

RE: California power grid, wildfires

The metals in the cables do not deteriorate in sunlight, but insulation does, unless you use the outrageously expensive stuff. Even then, something like Kynar is only expected to last 30 years. In any case, sufficiently thick Kynar to prevent arc-through would add 40% to the weight of the existing cables, which means that EVERYTHING needs to increased, tower strength, connections, cranes, transport trucks, etc. Note the latter means that additional truck trips are required to carry the heavier cables, per mile, so construction cost per mile is more expensive

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: California power grid, wildfires

Quote (RRaghunath)

Replacing the bare overhead conductors with insulated ones should reduce the wild fires at the same time not costing a fortune to do the work. Why is that not an option!
Full insulation would be similar to an underground cable. Too heavy, and cannot support itself. Covered conductor is sometimes used to prevent outages caused by wildlife, but when it falls, there is no fault and it remains energized on the ground with the utility unaware. Accidental encounters are unavoidable.

RE: California power grid, wildfires

One report claimed that one of the fires (not recent, but in last 10 years) started when the loop on an insulator from which the insulator hangs wore through or fatigued, dropping the insulator, the jumper connection, and the related transmission lines. This is similar to the Silver Bridge collapse.

I would expect that as that line fell it would hit the tower, causing a short and a massive arc; if it was insulated it would not immediately arc, but wear against the tower, unnoticed, until the insulation failed and it did short. There would be no indication of failure seen by the grid until either type of arc event.

State officials complained that the insulator failure would have been detected by a person climbing the tower, which is one thing that is done. But I think the transmission line has to be shut down to allow that, where helicopter surveys can happen with the lines still live.

Similarly there can be problems with the splices; failure inside the splice is difficult to inspect.

Perhaps there's an opportunity for building robots that operate like sloths, hanging from the lines and crawling along them with cameras and thermal sensors. They could climb the insulators and check the supports and provide high-magnification images of the splices. Helicopter surveys aren't close enough to see in detail and people climbing towers is likely to result in people getting killed.

RE: California power grid, wildfires

7
To answer Jay's initial post:
This is a failure of government.

PG&E has been offered (guaranteed) no competition, their customers have essentially no choice, and PG&E's profits and maintenance records have been explicitly approved by government regulators and politicians for decades.
And now California government (politicians) - many who receive generous campaign money - are assigning evil to this opportunistic firm. What do you expect? Do you blame a snake for eating mice? Of course not, that is what snakes do. The government has been tenderly nurturing this snake.

Capitalism is not on display here. Capitalism involves free choice, clear rules (regulation), and competition. None of these 3 existed, nor will exist, for PG&E.

When there is a single utility, this is a very similar situation as government-provided services.
Except one benefit for government: campaign cash. Public-owned utilities cannot directly provide campaign contributions. PG&E, however, provides millions of political dollars every year. This is why PG&E has existed all these years, despite historically poor customer service and significantly higher rates than adjacent government utilities like SMUD, and miserable maintenance records. The government loves the free money, even though they hate where it comes from.

If you think capitalism is the problem, buy a government-developed and marketed smart phone and car. Smart phones and cars have free markets, and 99% of us participate freely in these markets.

Tying this back to engineering and our profession:
I have worked for both private firms and public entities. Both have similar problems. However, getting rid of unmotivated and low quality employees in the public sector is nearly impossible. And these people are cancer to the moral of the department and the profession, but most government engineering departments keep these bottom feeders alive. The engineering community will excel when engineers have to compete; something that rarely happens in government.

RE: California power grid, wildfires

We are having a bad wildfire season in Australia as well, so can't send firefighters to help you this time.

RE: California power grid, wildfires

Short term fix may be to use eminent domain to widen the power line easements where falling trees cannot touch the high voltage lines.

RE: California power grid, wildfires

The sad part of all this is that it's going to be the customers, taxpayers, and small businesses paying the price for all of this nonsense. I know many in manufacturing are losing contracts for work they cannot deliver, and a few major companies that are viewing this as the proverbial final straw prior to relocating elsewhere.

RE: California power grid, wildfires

Probably the answer lies in micro and mini grids and avoiding the transmission lines through forests.
I know, easier said than done. But can we allow this destruction our limited forest wealth!!

RE: California power grid, wildfires

Quote (RRaghunath)

Probably the answer lies in micro and mini grids...
Probably not as hard today as it would have once been. Base load generation plants are slowly going away in lieu of smaller renewable sources and gas turbine generating stations so very high power transmission over great distances has a little less need today (however in California it looks like they'll be importing power from outside for the foreseeable future).

Brad Waybright

It's all okay as long as it's okay.

RE: California power grid, wildfires

There have been enough failures over the last 20 yrs that a statistical analysis should be completed that helps to focus on the 2 or 3 most likely failure modes for all such failures. The repair and upgrade procedures that should be adopted should focus on those 2 or 3 modes. Perhaps there are modern monitoring or detection devices that can detect the onset of failures, alert the dispatcher to allow shutdown of the offending wires and dispatch repair crews.

California has exported its power generation requirements, which in turn leads to the dependence on the long distance transmission system. In particular the increase in solar generation leads to the "duck curve" and an increased reliance on northwest hydropower, so I don't see any sort term decrease in reliance on the long distance transmission system. Overseas the newer tranmsmission lines are UHVDC with all sorts of solid state corrective devices ( sorry , I am not an EE), and perhaps an upgrade or modernization of the california transmission system would emlate the recent overseas advances.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

RE: California power grid, wildfires

Transmission lines are one thing, but distribution lines should be underground. Where I live, all new urban/suburban developments in the last 60 years have had underground power. I know that is impractical for rural areas, and prohibitively expensive for existing built-up areas, but it should be the goal. Where wildfires/bushfires are a recurring thing, building in those areas is always going to be hazardous, especially where so called conservationists get in the way of clearing undergrowth by proactive burnoffs.

RE: California power grid, wildfires

Where I live, virtually 100% of all distribution lines for power, TV, Tel, etc are underground, and it's been that way since they laid the first brick in town. Irvine, CA is a planner city, from the ground up as it were. During the 1970 census they estimate that there were 1,500 people living in what would someday be the city of Irvine. Officially the city was founded in 1971 with a master plan. 10 years later, when they conducted the 1980, which was the same year we moved to Irvine from Michigan, the city had a population of about 60,000. By 1990 that number was 109,000, and 141,000 by 2000. The 2010 census showed a population of 212,000. They now estimate that the population is 276,000.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: California power grid, wildfires

3
When the PG&E San Bruno Gas Line exploded, people were not just pointing the finger at PG&E, they were also blaming the California Public Utilities Commission. The California PUC was a plumb political appointment riddled with industry insiders and party cronies. People had been complaining about the Cal PUC for decades. Some changes were made to the Cal PUC after the San Bruno Gas Explosion, to at least show a semblance of a course correction but these days in a one party state the media doesn't bash the state for its failures.
There isn't any way to look at PG&Es current problem and not lump the California PUCs decades of favorable treatment into the mix. PG&E was a prized stock for retirees because it paid dividends. It was also the choice of institutional investors. More particularly, it was/is important to CalPERS, the money black hole known as the California Public Employees' Retirement System, which is guaranteed by California taxpayers,

RE: California power grid, wildfires

hokie66…

Quote (We are having a bad wildfire season in Australia as well, so can't send firefighters to help you this time.)


Can you at least run an extension cord over here? smile

I live in Fresno, in the San Joaquin Valley and far from the forests. I haven't experienced any of these "scheduled" power outages (yet). However, one cousin lives in the Oakland Hills (San Francisco area, East Bay) and one nephew lives near Auburn, uphill from Sacramento. Both of them have experienced a couple of these power outages so far.

Fred

==========
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

RE: California power grid, wildfires

Sorry, but we have enough problems of our own with reliability of supply. Queensland, where I live, is expected to supply power to the southern states which have shut down base load power stations, and are finding that relying on renewable energy is not all it's cracked up to be.

RE: California power grid, wildfires

That's always been the problem; no energy source is as easy to turn on/off as fossil fuel. The only other comparable alternative is nuclear, but it's got its own set of side effects.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: California power grid, wildfires

Quote (IRstuff)


...no energy source is as easy to turn on/off as fossil fuel.

That might be true in the case of natural gas-powered turbines or even diesel-powered generators, but in the case of coal fired plants, I suspect that the 'ease' of turning them ON and OFF leaves a lot to be desired.

However, isn't it true that Australia, in conjunction with renewable sources, is experimenting with the 'storage' of electrical power, both directly, using batteries, and indirectly, using other storage schemes, such as mechanical and physical (i.e. gravity assisted)?

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: California power grid, wildfires

Nevertheless, it's still a matter of hours, rather than the next diurnal cycle, but none of them are necessarily stopped cold; I would expect something like going from 40% of capacity to 75% of capacity would be relatively quick.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: California power grid, wildfires

JohnBaker,

I think "experimenting" is the correct term. Yes, batteries are being tried. A big Tesla one in South Australia, but that only provides power for a short time. Pumped storage hydro makes good use of excess capacity wind/solar when available, but sparsity of appropriate sites is limiting. Nuclear should be an option, but it is not palatable politically, yet. The base load capacity in the southern states, primarily coal, is aged and inefficient, and needs replacement.

RE: California power grid, wildfires

Nuke plants do not like to be ramped up and down either. Our local utility has quite a bit on nuclear power but uses pumped storage to smooth out the demand load.

----------------------------------------

The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

RE: California power grid, wildfires

Yes, nuclear with pumped storage is the ideal solution, IMHO.

RE: California power grid, wildfires

Nuclear power is too expensive compared to everything else. EIA releases a yearly report on the levelized cost of energy for all the different forms of generation. Nuclear power doesn't make any sense if you have access cheap natural gas or have good sites for wind and solar generation. Nuclear plants are being shutdown because they can't compete in unregulated regions in the U.S. Watts Bar 1 and 2 were the last two units built in the last 24 years and those are in regulated markets. The way that natural gas and renewables in the U.S. is going, no one should be talking about nuclear power until we run out of natural gas or start taxing anything that emits CO2. People keep trumping nuclear power because it doesn't emit CO2 and it seems like something that is easy to wrap your head around. It is just a coal plant that uses uranium instead of coal. It is almost twice as expensive as wind and solar in locations with good capacity factors.

https://www.eia.gov/outlooks/aeo/pdf/electricity_g...

RE: California power grid, wildfires

Nuclear is indeed too expensive at the moment, and probably will be for years to come. Thus, the need for more coal fired generation. There should be a mix. Speaking for Australia, which has plenty of coal, and exports a lot of it, coal is the most economical. If Japan, China, and India can use our relatively clean coal, why not us?

RE: California power grid, wildfires

Perhaps they should talk to those guys at the Navy research labs who have applied for a patent on a compact nuclear FUSION reactor:

https://www.thedrive.com/the-war-zone/30256/scient...

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: California power grid, wildfires

Yeah well, we'll see. Who remembers when fission was going to be "too cheap to meter"?

The problem with sloppy work is that the supply FAR EXCEEDS the demand

RE: California power grid, wildfires

Quote (SnTMan)


Who remembers when fission was going to be "too cheap to meter"?

I do. The below item is an excerpt from something I posted a couple of years ago:

One of the problems was that companies like GE and Westinghouse got into the nuclear power plant business but treated the reactors as just another source of heat, a replacement for the firebox in a coal/oil-fired power plant. They did not start with a bottom-up approach but rather tried to adapt existing technologies wherever the could get away with it. Also, in the early days, the public was sold on the idea that nuclear power would be so cheap that they might not even have a need for meters on people's houses. In other words, it was way oversold in terms of what it was capable of doing and for what the economics was going to be. It never lived up to its hype.

And then there was a very short period of time where the magic of so-called fast breeder-reactors caught the imagination of the industry, where not only would the production of electricity be dirt cheap, but that they would also be producing, virtually for free, the nuclear fuel, in the form a trans-mutated Plutonium created in the core of the Uranium-fueled reactor, that would then be used to fuel the next reactor built, a sort of nuclear perpetual-motion. BTW, this idea did NOT go well as the ONLY commercial fast breeder-reactor ever put into service, Fermi I near Detroit, had a near total melt-down of the core in 1966 (the term 'China Syndrome' was coined after this accident occurred). While there was no release of radiation as a result of this incident, the potential for disaster was much greater then in the case of a water-cooled reactor, like Three-Mile Island, since Fermi I used a closed-loop liquid-sodium based heat exchange system which if it had been breached, would have been a potential bomb in and of itself, surrounded by hundreds of pounds of enriched Uranium and deadly Plutonium.

They managed to repair the damage and the reactor was put back on-line in 1970 but was shut-down two years later and officially decommissioned in 1975, however the reactor was never completely dismantled and remains radioactive with its containment vessel sealed until some future date. In 1988, Fermi II, a light-water reactor, built adjacent to the then shut-down Fermi I plant, went on-line utilizing the original steam turbine/generating facilities.

BTW, back in 1962, when I was 15 years old, me and my family got a chance to visit the soon-to-be-completed Fermi I plant. My cousin was an electrical engineer working there while the plant was being built and he arranged for us to get a private tour of the facility, including being able to go right inside the containment vessel. I have to say, at that age and based on all the stories being told about how nuclear power was going to bring prosperity to the nation, it was a pretty cool experience.


And on that tour of the Fermi I plant, they had already opened the visitor center and they literally had a display making the claim that it was possible that sometime in the future, there would be no need for electric meters, that people would just pay a minimal monthly flat-rate for their electricity, generated by nuclear power plants like Fermi I, fast-breeder reactors.

Which brings to mind something that actually did happen in California. When a protracted drought hit the state about 10-12 years ago, they started to threaten people in places like L.A. that they could be fined for over-watering their lawns or rinsing their driveway with a hose. Anyway, someone noted that the people living in the Sacramento area didn't even have water meters, they simply paid a flat rate based on the size of their house and yard. In other words, there was no incentive to stop excessive water usage, not like there was in most of the rest of the state, particularity Southern California. It took awhile, but that situation was eventually corrected.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: California power grid, wildfires

According to the recent article in the Nov 2019 POWER magazine, none of the existing 674 nuclear reactors on planet earth were built based on economic justification, and all were constructed using some form of military , scientific, or national objective as the primary rationale. The local laws or regulations were deliberately adjusted to ensure adequate remuneration for the clients and fabricators. Once a country is invested in nuclear plants, then it remains necessary to retain nuclear expertise for the indefinite future until the waste products are permanently dipsosed of, and this could imply artificially enhancing the career prospects for nuclear technicians for centuries ( a so called nuclear priesthood).This may explain HPC ( and Vogtle), since it was reported that it will take a minimum of 120 yrs to retire Windscale ( and hanford). The genie simply refuses to go back into the bottle.

The design code for reactors includes fatigue provisions, but the installed base of reactors are not designed for fast load changes or fast startups. The ASME boiler design code (ASME section I ) however does not even contain a single instance of the word "fatigue", and large coal fired boilers and HRSGs designed only to section I might not have specifically been designed for fatigue damage unless the mfr added his own provisions for fatigue , using either asme sect VIII div 2 or EN- 12952-3 fatigue guidelines.

The large number of HRSG's designed in the bubble period 1999-2009 were designed for the highest possible efficiency at full base load due to the high cost of natural gas during that period, and were not designed for fast startups nor 2 shift cycling operations.The fracking revolution in the US reduced the price of fuel gas by a factor of 5 after 2009, and the increasing use of renewable power ( wind , solar PV) forces combined cycle plants to 2 shift cycle and also places a large economic bonus on plants that can start up quickly . This new design objective implies fatigue damage plays the primary role in the design of the HRSG and related plant systems, to allow fast startups.

The newest frame gas turbines can allegedly turn down to 15% MCR load to allow spinning reserve operation. The installed base of older combined cycle plants could theoretically be retrofit with modifications to also allow spinning reserve operation, which in turn permits fast load increases as the components remain in a hot standby mode.However, such modificaitons do not seem to be pursued and these older plants are losing economic relevance.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

RE: California power grid, wildfires

We want taxpayers' money to be used to prevent fires, not to put them out。

RE: California power grid, wildfires

"We want taxpayers' money to be used to prevent fires, not to put them out"

We're now re-learning the lesson that the very prevention of forest fires leads to the disasters we have now. We learned this lesson 20 yrs ago, but apparently forgot it. Had we allowed the random fires that naturally start to run their courses, there would have never been the thick buildup of brush and undergrowth that sustain today's fires to the point where all the trees completely burn.

And DON'T build in the f***ing forest!

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: California power grid, wildfires

"And DON'T build in the f***ing forest!"

Our house is in the forest, surrounded by trees. But forests in Nova Scotia are typically so damp that they're less likely to catch fire. It's not impossible, but it's not a huge concern either.

Last night we had a wind storm (gusts ~110 kmh), and there are now hundreds of power outages. Many outages would have been caused by swaying trees contacting the medium voltage lines. No reports of forest fires.

Acknowledge that the situation in dryer climates is different.

RE: California power grid, wildfires

In California, we've been in drought conditions, off and on, for a decade. The intermittent rain pattern, I think, makes the situation worse, since it naturally selects faster-growing plants that might be less robust against fire. And, large parts of California are borderline desert to start with.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: California power grid, wildfires

And much of that has a fire based ecology anyway. Nature wants to burn in much of California, that's how the ground is cleared and seeds released for the next generation of plants. It needs to burn, but many small fires will accomplish that better than infrequent conflagrations.

RE: California power grid, wildfires

Sure, but Smokey Bear signs are still abound.

At this time in history, even "controlled" burns are dangerous; we've had a few get out of "control," simply because there's way too much fuel.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: California power grid, wildfires

A large part of the problem is that the state and the counties continue to permit building homes in areas that have a high risk of fire. If that permitting process cannot be halted, then the design standards for those homes must be made more " fire resistant" ( steel roofs, hardey board siding, steel window shutters, increased clearance to brush) and the insurance premiums jacked up to stupid status. And, most important of all, the residents should stop b##ching after each and every fire, as if they didn't know it was an accepted risk.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

RE: California power grid, wildfires

Brush clearance isn't remotely going to hack it for the big fires, particularly when those types of fires can jump 4-lane highways. There are lots of roofing materials that provide comparable fire resistance besides steel. But all of them (steel, concrete, aluminum, slate) are substantially more expensive than the typical asphalt shingle roofs; they can easily add $30k cost to a small house.

But, I've got a similar beef with those that build on flood plains and then re-build with no changes on the same plot, knowing they'll get flooded in a few years. Most such houses need to be sitting on a minimum of 6 ft stilts.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: California power grid, wildfires

Brush clearance reduces radiant heat load. It may not prevent the fire from spreading, but I look at the Paradise Hospital which was successfully defended by one guy with a small watering hose able to keep ahead of the embers.

RE: California power grid, wildfires

I believe a major factor causing the increasing damage caused by wild fire are the mandatory evacuations being so strictly enforced. If there is no one around to put out those tiny embers, fires will start.

RE: California power grid, wildfires

I don't know how slight that is - Paradise satellite photos showed the entire area was packed with fuel; there were whole neighborhoods where only small amounts of house roofs were exposed under trees, with trees covering what appeared to be 80% of the ground. Once that goes it's like being under an oven broiler.

RE: California power grid, wildfires

Ummm, it was burning at 48.6 acres PER MINUTE. Traversing at 40 meters per second. 89.5mph.

Good luck with your garden hose.

Keith Cress
kcress - http://www.flaminsystems.com

RE: California power grid, wildfires

How hard would it be to build a house that could survive a forest fire relatively undamaged and be able to house occupants? During the last fire, there was a guy who didn't leave and he was out there with a water hose and rake and he managed to get through it. Not that is a benchmark but it makes you wonder if it would be easier to force everyone to have fire proof homes than to manage the forest.

RE: California power grid, wildfires

My wife the firefighter would say that all fires are dangerous and none minor, its simply a matter of landowners and the state both taking responsibility for the necessary maintenance. My property is roughly centered in a large hilly subdivision of larger wooded lots, most well over an acre. Many of us have a significant patch of woods and every few years we bring in the fire dept and have a community burn day. Growing up on the farm in NY we participated in larger controlled burns of govt land, and burning was how the family sawmill rid itself of the slab pile annually. I don't think the extreme greenies were ever happy about it, but that's how its always been done and can be a very safe activity if folks are proactive about it.

RE: California power grid, wildfires

Dave's point about "...like being under an oven broiler" is extremely important.

Far too many people don't instinctively know about radiant heat.

---

Years ago, there was a local news item about a forest fire. One house in the path of the advancing flames was shown being covered with some sort of wet thick spray foam. Of course it survived unscathed while everything around it burned.

I'm left wondering why this isn't a regular option by now.

RE: California power grid, wildfires

Quote:

Far too many people don't instinctively know about radiant heat.

I think they do "instinctively" know, but they don't know the physical process, since pretty much everyone has felt the radiant heat from the sun, stove, light bulbs, etc. What might be surprising is the sheer intensity of even a simple brush fire

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RE: California power grid, wildfires

It's the effect of the solid angle (steradians) that is so often unexpected.

Bleves (boiling liquid expanding vapor explosions) can be dangerous for the same reason.

RE: California power grid, wildfires

You can build houses that won't burn. That's what should be done. They may look a bit different but that's just the requirement for living in that kind of space. There's a standard for making or building fireproof (from external causes) houses. I think they should should be a bit more radical than the "Fire Resistant" requirements and make them fire proof. That way everyone can shelter-in-place while not fleeing into the unknown of the roads during a catastrophe.









These three houses were the only ones in the area built with ICF tech.



This house was also ICF with the exception of the garage that in a subsequent fire burnt to the ground but it left the house undamaged. That's a wood structure against the house that couldn't even burn the house!!







Same goes for hurricanes. You can build hurricane proof houses and they all should be.

Keith Cress
kcress - http://www.flaminsystems.com

RE: California power grid, wildfires

ICF is new to me. Can houses withstand these sorts of fires repeatedly without any concern, or is it a one time deal and then you need to go in and repair stuff?

What about the cost impact vs. a 'traditional' option?

RE: California power grid, wildfires

Historically, many cities were originally built using wood siding and wood or asphalt roofs. Many of these cities had catastrophic city wide fires, and rebuilt using brick siding and slate roofs to reduce the spread of fires, espescially if near a steam locomotive track (as the unburnt cinders from the locomotive would start house fires).

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

RE: California power grid, wildfires

Quote:

Can houses withstand these sorts of fires repeatedly without any concern, or is it a one time deal and then you need to go in and repair stuff?

Repeatedly. However, you might need to repair a few things after a thorough toasting. Frequently you may need to replace some windows because the intense IR or even flame contact can crack or break them or simply overheat the multi-pane structures with gas-fills and anti-UV coatings. Note the second picture from the top. They lost windows because they had flammable plants against the house!

Keith Cress
kcress - http://www.flaminsystems.com

RE: California power grid, wildfires

Did I miss something? What is ICF tech?

RE: California power grid, wildfires

Insulated Concrete Forms.
I wouldn't want to shelter in place in a home with that much polystyrene insulation just behind the siding.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: California power grid, wildfires

Its not ordinary polystyrene. We did a basement using it. I chucked a bit on an open fire to see what happened. It just melts. The basement has a heat pump with 500 ltrs of glycol in the ground loop and the building is made out of logs and timber. I Was interested in case somehow the glycol went on fire. It shouldn't do though as it has a bit of water in it.

The concrete won't let fire through so it can't get at the interior. Takes ages for the heat flow to get the inside hot anyway from memory the bloke said it was 4 hours with the foam melting and puddling, he didn't have a clue how long before it hit its flash point or for that matter what temp.

The only weak spots are the windows and other openings and the fire getting past them aka the Grenfell cladding disaster.

I suspect the biggest danger would be running out of oxygen as the fire raged round the house using it all if you stayed in.

RE: California power grid, wildfires

Quote (Alistair)

Its not ordinary polystyrene.
This is the difference:
FIRE RESISTANCE
The flame retardant currently used in polystyrene foam insulation is HBCD. Hexabromocyclododecane (HBCD) is an additive flame retardant that promotes increased fire resistance in polystyrene foam insulation building and construction applications. This allows polystyrene foam insulation to meet the stringent fire safety requirements governed by the International Code Council and National Building Code of Canada, providing increased protection to buildings and building occupants. HBCD has also been used as a flame retardant in solid plastics such as high impact polystyrene and in carpets, upholstery and other textiles.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: California power grid, wildfires

The thing about halogenated flame retardants is that they do interfere with the ignition and self-propagation of burning in the treated material. However, they can not do much about the heat released by the plastic (caloric content) when it is engulfed in a fully developed fire. Intense radiant heat will keep the fire going, but now you will also have noxious hydrobromic acid in the smoke.

RE: California power grid, wildfires

The flash point is higher and the concrete stops the naked flame getting to them unless there is a weak spot that it can get through. It takes hours for the inside wall to get hot enough. By which point the fuel supply outside is used up.

RE: California power grid, wildfires

Great, but ICF is on the inside and the outside.

I expect Alistair's basement is safe from California wildfires no matter what.

RE: California power grid, wildfires

True but it's more to protect the upper wooden log house from the heatpump and solar inverter and battery going up.

Round the outside I have 500 meters away from the silver birch wooded land. Which sometimes does go up. There are mandatory fire breaks though for commercial wood blocks which in the last 10 years seemed to have done the job. We get up to 35 Deg C in summer and -25 in winter with most of the rain fall in oct. So August/September is the danger period. Different climate but similar risks.

You can take the foam off after the concrete is cured.If the outside layer gets burned off you don't need to replace it unless you want to get back the thermal insulation properties. We removed the internal wall foam to give more space.

RE: California power grid, wildfires

Allistair,

I don't think oxygen is an issue if you stay low. When the firefighters use their emergency foil tents, it is all about breathing in air low to the ground that is still not too hot. I think I have heard the phrase "if the fire can burn there is air to breath".

RE: California power grid, wildfires

I think I will be a coward and not personally test that theory.


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