World's Largest Solar Plant Sets Itself on Fire - Page 1
Forum section: electronics / general

author: TerraHertz
author_rank: Super Contributor
timestamp: May 22, 2016, 01:01:08 am
content: From the "Nothing can possibly go wrong" department:http://www.popularmechanics.com/technology/infrastructure/a20972/worlds-largest-solar-plant-sets-itself-on-fire/World's Largest Solar Plant Sets Itself on FireImproperly aligned mirrors redirected the sun's rays at the wrong spot.Oh, and from last year:https://wattsupwiththat.com/2015/03/02/test-at-tonopah-solar-project-ignites-hundreds-of-birds-in-mid-air/

author: SeanB
author_rank: Super Contributor
timestamp: May 22, 2016, 05:31:34 pm
content: Oops, not exactly easy to turn off the sun if you want to stop it either with a failed mirror bank.

author: coppice
author_rank: Super Contributor
timestamp: May 22, 2016, 05:51:09 pm
content: That seems like lousy design. With the ever present possibility of a mirror fault pumping energy onto any part of the faces of the towers, you'd think they would make those faces extremely heat resistant.

author: ruffy91
author_rank: Regular Contributor
timestamp: May 22, 2016, 06:04:25 pm
content: Just make the face reflecting. The mirrors are focused on the tower so if you reflect the rays they are out of focus and won't hurt anyone.

author: lemmegraphdat
author_rank: Frequent Contributor
timestamp: May 22, 2016, 11:17:36 pm
content: More green jackassery.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 22, 2016, 11:33:43 pm
content: QuoteIMO this is still preferable to fossil fuel jackassery, eg. Deep water horizon.QuoteI don't know what really happened but this purports to be from a primary source.

author: ZeroStatic
author_rank: Contributor
timestamp: May 24, 2016, 12:35:45 am
content: Nobody bothers anymore counting how many animals have been killed by fossil fuel mining and burning to produce power, let's all just point out the small failures of the new technology.

author: djacobow
author_rank: Super Contributor
timestamp: May 25, 2016, 04:54:22 pm
content: Quote from: TerraHertz on May 22, 2016, 01:01:08 amJust for the record, these news items refer to two separate plants. Ivanpah, a project of BrightSource Energy, is the one that had the fire. The one with the large alleged bird kill, Tonopah, was built by SolarReserve. There have been bird kills at Ivanpah, too, but that plant has been operating longer and there is more data. The numbers, if I remember correctly, are not any higher than for wind projects, or for tall buildings for that matter. Here's another article on the topic:http://breakingenergy.com/2014/08/27/a-solar-bird-death-story-ignites-controversy/#commentsAlso, the operators say that they have not seen any avian mortality since they updates their standby algorithms:http://social.csptoday.com/technology/crescent-dunes-curbs-avian-risk-after-standby-algorithm-change(disclosure: I used to work for BrightSource)

author: zapta
author_rank: Super Contributor
timestamp: May 25, 2016, 05:39:21 pm
content: Quote from: ruffy91 on May 22, 2016, 06:04:25 pmA few smoke grenades around the tower should buy you repair time until sunset.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 25, 2016, 06:06:41 pm
content: The damage pictures don't look that bad. So a niche headline - but nothing serious.That's the principle problem with a large power station - there is a lot of energy to do har, when something goes wrong. It's similar with dams, wind turbines, natural gas plants, oil wells and nuclear power. The relatively low power density of the renewables also have a good side.I won't expect a little smoke do much against a high light power. The smoke gets hot and will rise by thermal effects. Also wind can make this a rather short time solution, especially further up in the tower.

author: Red Squirrel
author_rank: Super Contributor
timestamp: May 25, 2016, 08:39:43 pm
content: I still think this is a neat concept. As for birds, fossil fuel still kills WAY more wildlife. They could try to find ways to stop/reduce birds from going there.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 25, 2016, 09:41:07 pm
content: "Plant personnel had fire out by the time firefighters arrived"I can see it now -- "Go on Jim, climb the tower. We'll have the mirrors pointed somewhere else by the time you get up there."All humor aside, there is a lot of sunshine being redirected here. And light goes a long ways in the atmosphere. The safety software and hardware on an installation of this size really matters. To those at the plant site. To neighbors. To airplanes flying in the area. Maybe even to the International Space Station.

author: Red Squirrel
author_rank: Super Contributor
timestamp: May 26, 2016, 01:56:51 am
content: Imagine something like that weaponized. You could basically give it a 3D coordinate and it would do all the calculations to focus all the mirrors at that one spot. Could probably take down a plane like that.It could work with radar too, you tell it to aim at a point on the radar and it figures out where it is, and follows it.I am now on a list. Probably get arrested next time I try to buy anything reflective.

author: zapta
author_rank: Super Contributor
timestamp: May 26, 2016, 02:52:16 am
content: Quote from: Red Squirrel on May 26, 2016, 01:56:51 amHopefully the enemy is not smart enough to attack at night.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 26, 2016, 04:01:13 am
content: I would be more concerned about a blinding/burning attack on an airliner. Terrorist subverts the aiming software. Probably somewhere between hard and impossible to achieve burning, but since focus isn't as critical for blinding I hope their firewalls and other software protection is good.

author: Ian.M
author_rank: Super Contributor
timestamp: May 26, 2016, 04:31:42 am
content: The mirror flatness, mounts and aiming mechanisms only have to be accurate enough for the reflected beams to hit the heat collector reliably. At any significant range (relative to the installation size) the combination of dispersion of individual beams and statistical uncertainty of the aiming point for each mirror will make it near impossible to achieve any dangerous concentration of light, let alone track a moving target. Also, the shading effect means the effective array area is vastly reduced at low angles so there is little risk to distant stationary or near-stationary terrestrial targets.

author: boffin
author_rank: Unknown
timestamp: May 26, 2016, 06:30:50 am
content: Quote from: CatalinaWOW on May 26, 2016, 04:01:13 amThe interesting thing is that it's only a few miles from the proposed new Las Vegas (Ivanpah) airport site.

author: wagon
author_rank: Frequent Contributor
timestamp: May 26, 2016, 07:08:15 am
content: Quote from: zapta on May 25, 2016, 05:39:21 pmFixed for you.

author: Red Squirrel
author_rank: Super Contributor
timestamp: May 30, 2016, 04:56:50 am
content: Quote from: zapta on May 26, 2016, 02:52:16 amThere's always the reflection of the moon!Actually, I'd almost be curious to see how bright you could get a spot using the moon and something like this. I wonder if there would be any significant energy like for PV panels. I don't imagine so though, the actual energy would already have been absorbed by the moon. I think?Now I'm curious to bring some solar panels outside next time the moon is super bright, and play with mirrors. Maybe you need lunar panels for that.I smell a potential indigogo campaign.

author: zapta
author_rank: Super Contributor
timestamp: May 30, 2016, 05:30:43 am
content: Quote from: Red Squirrel on May 30, 2016, 04:56:50 am"The full Moon is about 1,000,000 times fainter than the Sun"https://en.wikipedia.org/wiki/Moonlight

author: babysitter
author_rank: Frequent Contributor
timestamp: May 30, 2016, 08:54:49 am
content: https://translate.google.de/translate?hl=de&sl=de&tl=en&u=http%3A%2F%2Fwww.josella-simone-playton.com%2Fsolarpow.htmlcomes to mind...

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: May 31, 2016, 08:42:40 am
content: Quote from: Red Squirrel on May 30, 2016, 04:56:50 amI can't remember the exact proof at the moment and I'm a bit busy to go looking for it but I'm pretty sure you can't heat a surface with a magnifying glass hotter than the surface of the thing radiating the energy. Something to do with thermodynamics and entropy.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 31, 2016, 05:03:52 pm
content: Quote from: DenzilPenberthy on May 31, 2016, 08:42:40 amThat would be true if the moon was the source of the energy. The obvious evidence that this analysis doesn't apply in this case is the normal operation of the solar energy system. The mirrors are never hotter than something like 60-70C, but were able to cause a fire when a small section of them were misaimed.The million to one losses in reflection off the surface of the moon are the real issue.

author: babysitter
author_rank: Frequent Contributor
timestamp: May 31, 2016, 10:11:02 pm
content: Quote from: DenzilPenberthy on May 31, 2016, 08:42:40 amhttps://what-if.xkcd.com/145/

author: MotorMagic
author_rank: Newbie
timestamp: June 08, 2016, 02:45:46 am
content: I like the idea of making the portions of the tower which need to be insulated, reflective. Might make the towers look even more badass then they already do.Quote from: lemmegraphdat on May 22, 2016, 11:17:36 pmI prefer a small cable fire to fly ash and cancer.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: June 08, 2016, 03:44:57 am
content: Quote from: babysitter on May 31, 2016, 10:11:02 pmMost of the arguments in this link are true, but the main point in the link is NOT applicable. The vast majority of "Moonlight" is not light generated by the moon, it is light from the sun reflected from the moon. So the limiting temperature based on thermodynamic arguments is the 6000 degree temperature of the surface of the sun. If the moons surface were a flat reflector (or even better a slightly concave reflector), you could start fires by this "moonlight". The reality is that the moons surface is a roughly lambertian reflector, and scatters the light reflected over an entire hemisphere, or a solid angle of pi steradians. A magnifying mirror on the earth can only collect the portion of this light equal to the solid angle subtended by the lens divided by pi. That solid angle is roughly the area of the lens divided by the square of the distance from the earth to the moon, so the attenuation is enormous.

author: djacobow
author_rank: Super Contributor
timestamp: June 08, 2016, 06:04:07 pm
content: Quote from: CatalinaWOW on June 08, 2016, 03:44:57 amSo just to clarify because I'm a bit thick: you are saying that itistheoretically possible to start a fire with moonlight, but that the efficiency of the system is so low that it is practically impossible?Just for the record, the mirror array around a single tower at Ivanpah is about 2,600,000 m^2.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: June 09, 2016, 04:12:31 am
content: Quote from: djacobow on June 08, 2016, 06:04:07 pmAfter further thought, I do believe it is very nearly impossible, if not flatly impossible. I still reject the thermodynamic argument, which applies when objects are thermally radiating. The simple counterexamples are the burning mirrors, solar energy plants, and solar furnaces which quite handily heat things to large fractions of solar temperature with no comparable rise in mirror temperature. The temperature of the reflector is irrelevant.The limiting factor involves another principle which is mentioned in the link. A thought experiment will show the problem. Imaging a large spherical mirror (half of a hemisphere and radius substantially larger than the moon). In this case spherical describes the shape, the mirror is actually a segment of a sphere. This mirror could, in principle return all of the energy reflected from a point on the moon. With a suitable adjustment in shape it could deliver it to any other point between it and the moon, perhaps on the surface of the earth. But that mirror cannot also reflect energy from other points on the moons surface to that same spot, so the power density delivered is the power density delivered at the moons surface by the sun, less losses from reflection. The moon absorbs about 90% of sunlight, reflecting about 10%. That 90% absorbed raises the temperature of the moon to only about 125 deg C, well below ignition temperature for most materials. The temperature of the moons surface is limited by thermal conduction to the interior. If you could better thermally isolate your moon reflection point, and choose a material with a very low ignition point, it is remotely conceivable that you could achieve ignition with this nine times lower energy flux. But anything smaller than this impossibly big mirror with a carefully contrived ignition target will fail.

author: Artlav
author_rank: Frequent Contributor
timestamp: June 12, 2016, 09:49:54 pm
content: Heh, in the Niven's classic story Ringworld there are sunflower plants with a mirror instead of seeds.And, they reflectively aim sunlight towards any moving things.Imagine flying over an indefinite field of them.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: June 13, 2016, 12:19:47 am
content: One of my favorite fiction stories (might even be called science fiction) involves a city which feels the home soccer team has been unfairly treated by a particular set of referees. A silvered program with appropriate instructions is issued to the crowd and the problem is solved. Technically feasible, practical details get in the way. Flatness of a mirrored program. Ability of each individual to aim his program and so on, but there is plenty of energy falling on a stadium.

author: bitslice
author_rank: Frequent Contributor
timestamp: June 13, 2016, 12:34:30 am
content: Quote from: ZeroStatic on May 24, 2016, 12:35:45 amThere is definitely no dinosaurs left, I looked.

author: mtdoc
author_rank: Super Contributor
timestamp: June 13, 2016, 05:19:30 am
content: Quote from: djacobow on June 08, 2016, 06:04:07 pmI've seen measurable wattage from a solar PV array during a full moon. So theoretically that power could be used to start a fire.

author: BillyD
author_rank: Regular Contributor
timestamp: June 13, 2016, 07:06:52 am
content: Quote from: CatalinaWOW on June 13, 2016, 12:19:47 amYes I can clearly remember reading that story too as a teenager! I think it was a book of short stories titled 'Science Stories For Boys' or somesuch, and the front cover had a picture of a guy operating an exoskeleton robot, good reading at the time!