EMP and Solar System Protection

Alaska Man
Alaska Man Solar Expert Posts: 252 ✭✭
Not only could an Electro Magnetic Pulse ruin your system, but I learned last night on Coast to Coast that a Solar Flare could do even worse damage. I'm not an end of the world prepper; too busy living to think about all the ways one can die. However, I did wonder if there was any way to protect the parts of the system that could be damaged by either event?

I'm thinking Controllers, Chargers and Inverters are what’s vulnerable. Panels and batteries would be okay, I think.


Any one else ever ponder this?
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Comments

  • AuricTech
    AuricTech Solar Expert Posts: 140 ✭✭
    Re: EMP and Solar System Protection
    Alaska Man wrote: »
    Not only could an Electro Magnetic Pulse ruin your system, but I learned last night on Coast to Coast that a Solar Flare could do even worse damage. I'm not an end of the world prepper; too busy living to think about all the ways one can die. However, I did wonder if there was any way to protect the parts of the system that could be damaged by either event?

    I'm thinking Controllers, Chargers and Inverters are what’s vulnerable. Panels and batteries would be okay, I think.


    Any one else ever ponder this?

    The easiest way to protect your charge controller, charger and inverter from EMP (natural or manmade) is to keep a spare in a Faraday cage.

    Fortunately, that's not as difficult as it sounds. Here are links to two improvised Faraday cages:

    Faraday garbage can

    Faraday paint can

    You don't want to ground such small Faraday cages (the ground wire itself may become an antenna). Just keep the electronics insulated from the inside of the can, and you should be all right.

    ETA: For a coronal mass ejection, you can also disconnect everything to reduce the antenna effect of your wiring, since you'll likely have a couple days notice.
  • Alaska Man
    Alaska Man Solar Expert Posts: 252 ✭✭
    Re: EMP and Solar System Protection

    Right on, Thanks.
  • PNjunction
    PNjunction Solar Expert Posts: 762 ✭✭✭
    Re: EMP and Solar System Protection

    The bypass diodes in the panel junction boxes would be shot, so you'd better keep some wire and crimpers handy for bypassing them. Not to mention that the cells themselves are basically diodes, and I wonder how much of a blast would take them out directly.

    Ok, so you fix that with jumpers, but your controller is shot. That means attaching panels directly to the battery, and just being quick on the draw to remove them when they reach about 80% SOC, otherwise you'll fry them. With your monitoring dead, perhaps even just your voltmeter, the only thing you could rely on would be FLA batteries and a hydrometer. Still, you'd only be taking them to 80% SOC or so unless you happen to be a good human-regulator. :) Given long enough with this condition, they will sulfate and die.

    With your AC inverter shot, the only thing left to run would be dc applicances directly from the battery - and assuming that some of those appliances actually survive. Even if they do, there would be no radio, tv, internet, cellphones etc for at least a very long period of time, so if your inverter makes it, what would you do with it, other than just quickly consume what you already have - say in a small freezer that somehow survived. Lighting? Most CFL's contain circuitry, and they too just might go pop.

    Heh, too many variables to prep for. Might make a good movie however. Back to candles and eating grubs. I suppose one could drain the FLA's, and use them for counterweights on the homebrew catapults. :)
  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
    Re: EMP and Solar System Protection
    PNjunction wrote: »
    The bypass diodes in the panel junction boxes would be shot, so you'd better keep some wire and crimpers handy for bypassing them. Not to mention that the cells themselves are basically diodes, and I wonder how much of a blast would take them out directly.

    Natural EMP events result in large magnetic fluxes over large areas. These induce currents in large structures, but the current induced is dependent on the area exposed. A modern solar power system is going to have a fairly small loop area exposed, and will also be designed to tolerate fairly large excursions in both current and voltage.

    The field strength numbers I have seen for a strong (Carrington-level) solar flare event range from between 1 and 10 amps per meter at the surface. This can induce huge voltages (and currents) over a 100 mile transmission line, but locally won't do as much. For reference a wireless charger for a phone will put out 40 amps per meter, and can damage RFID cards but won't damage anything more beefy (like a cellphone.)

    Nuclear EMP events can hit 150 amps per meter which means even a small loop is going to pick up a lot of current/voltage. That means a connected solar power system is going to be at risk, but a disconnected one will tend to survive.
  • PNjunction
    PNjunction Solar Expert Posts: 762 ✭✭✭
    Re: EMP and Solar System Protection
    ..That means a connected solar power system is going to be at risk, but a disconnected one will tend to survive.

    Sure, but other than short-term local outages, what major infrastructure will be left for your solar system to interface with? With no radio, tv, cellphones needing to be charged, I suppose that will save some energy. We're looking at some major general mayhem for long term, and unless you are willing to protect it, your solar system makes an inviting target and beacon for those doing without.

    In my case, I'll just be getting out of Dodge and solar will be the last thing on my mind. Or stick around, and be the only one on my block prepared with my lead-acid catapult! :)
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: EMP and Solar System Protection

    shame on C2C guest for the mis-information. Solar EMP is "low grade", and need thousands of feet of wire to have an effect. But if a man-made event happens. then that EMP can cause mayhem for thousands of miles, just inches of wire exposed.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • Alaska Man
    Alaska Man Solar Expert Posts: 252 ✭✭
    Re: EMP and Solar System Protection

    The last Solar EMP flare was in the late 1800's and took out the telegraph lines at the time. I guess that's where your reference to thousands of miles of wire comes in?
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: EMP and Solar System Protection
    Alaska Man wrote: »
    The last Solar EMP flare was in the late 1800's and took out the telegraph lines at the time. I guess that's where your reference to thousands of miles of wire comes in?

    I said FEET, not miles :) And it zapped RR tracks too.

    But solar emp is very slow, and needs long wires to cause effects
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: EMP and Solar System Protection

    As Mike says--It is the frequency (EM field wave length) vs the wave length of the "antenna" receiving the power.

    Solar flares will (as I understand) only affect "wire loops" on the order of miles in length... Something as small as an off grid solar power system is just not large enough to efficiently receive the EM energy.

    Having spares is always a good idea in remote areas where you rely on the off grid power system.

    EMP (nuclear electro magnetic pulses), at least the ones we can do anything about, are also relatively low frequency--And the farther away, the more the high frequency energy is attenuated.

    Making a PV system survivable in EMP/CME conditions?

    We have a few threads here about CME and EMP:

    Solar Flares/Sun spots

    EMP
    EMP
    HAM with some EMP

    From my post in the Ham Radio thread:

    This guy wrote something that I pretty much agree with (with my limited education):
    To answer the specific question of the OP, it depends upon the application. Military electronic hardware, save for acceptable commercial-off-the-shelf (COTS) components, area built to specific interface standards like MIL-STD-464 (Electromagnetic Effects Requirements for Systems), MIL-STD-461 (Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment), and MIL-STD-2169 (Classified) (High Altitude Electromagnetic Pulse Environment). The latter is probably most pertinent to the question, and for obvious reasons unavailable to the public at large. However, the ugly truth about high altitude EMP is that no amount of shielding, save being buried deep under hundreds of feet of rock or dirt, is really adequate to protect sensitive microelectronics. By their nature, the electronics are delicate and sensitive to small levels of excess voltage, and it is nearly impossible to make a practicable sensor, communication system, or avionics control that has to interface with the outside world and yet is adequately isolated against large pulses.

    High altitude EMP (HEMP) devices produce three distinct regimes of pulse, referred to as E1, E2, and E3. Microelectronics are most sensitive to E1, which is due to interaction of x-ray and gamma ray radiation with the rarified upper atmosphere and the geomagnetic field resulting an a nearly coherent, widely distributed pulse, sort of like a very large free electron maser. In more dense atmosphere where the the rays are rapidly absorbed and don't have much length to deflect, this pulse is serious attenuated, and the amount of damage done but the physical effects of the blast (shock and thermal wave) would likely make E1 effects moot. E2 is more like static electricity, and can typically be shielded by using a protected ground or faraday cage type shielding. E3 is energy that is stored in the Earth's magnetic field (similar to that which comes from coronal discharges and solar flares) and will cause longer term disruption and very high voltage spikes in large arrays like power grids; again, not much of a threat to microelectronics.



    So, from my point of view, the solar flares produced relatively low frequency changes in magnetic fields... Probably would take structures on the size of miles or 10's of miles to capture the energy (1/4 wave length or larger?).

    Here is a wiki entry for geomagnetic storms:
    Electric grid When magnetic fields move about in the vicinity of a conductor such as a wire, a geomagnetically induced current is produced in the conductor. This happens on a grand scale during geomagnetic storms (the same mechanism also influences telephone and telegraph lines, see above) on all long transmission lines. Power companies which operate long transmission lines (many kilometers in length) are thus subject to damage by this effect. Notably, this chiefly includes operators in China, North America, and Australia; the European grid consists mainly of shorter transmission cables, which are less vulnerable to damage.[12]

    The (nearly direct) currents induced in these lines from geomagnetic storms are harmful to electrical transmission equipment, especially generators and transformers — induces core saturation, constraining their performance (as well as tripping various safety devices), and causes coils and cores to heat up. This heat can disable or destroy them, even inducing a chain reaction that can blow transformers throughout a system.[13][14][15] This is precisely what happened on March 13, 1989: in Québec, as well as across parts of the northeastern U.S., the electrical supply was cut off to over 6 million people for 9 hours due to a huge geomagnetic storm. Some areas of Sweden were similarly affected.
    According to a study by Metatech corporationI][URL="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed"]citation needed[/URL][/I, a storm with a strength comparative to that of 1921, 130 million people would be left without power and 350 transformers would be broken, with a cost totaling 2 trillion dollarsI]not specific enough to [URL="http://en.wikipedia.org/wiki/Wikipedia:Verifiability"]verify[/URL][/I.

    By receiving geomagnetic storm alerts and warnings (e.g. by the Space Weather prediction Center; via Space Weather satellites as SOHO or ACE), power companies can (and often do) minimize damage to power transmission equipment, by momentarily disconnecting transformers or by inducing temporary blackouts. Preventative measures also exist, including digging transmission cables into the soil, placing lightning rods on transmission wires, reducing the operating voltages of transformers, and using cables that are shorter than 10 kmI][URL="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed"]citation needed[/URL][/I.

    I do not believe that an off-grid solar array, backup generators, inverter, etc., would be susceptible to a solar flare event.




    For grid tied systems--there may be a risk of damage from surges on power company transmission lines entering the home electrical system (guess on my part).

    An easier way to search our forum... Use Google and the "site:forum.solar-electric.com" tag to limit searches to our forum (or type in the web address of other sites you are interested in). For example:

    • EMP site:forum.solar-electric.com

    Short search terms here work much better with Google than the forum search tool.

    -Bill

    Updated the "site:" tag to reflect our new URL: site:forum.solar-electric.com

    So--My two cents. Don't worry about Solar Flares--Except at the point your home (and telephone/cable/etc.) where the electric utility power enters your home.

    For off grid homes, the risks are from nearby/direct lightning strikes. And if you do a good job of protecting against lightning (surge protectors, grounding, lightning rods, proper grounding conductors for lightning), then there is no reason to do any more "protection".
    BB. wrote: »
    A couple threads about Lightning:

    Off Grid Grounding Technique?
    Another Question, this time about Lightning

    Note, the above are discussions, not a do A, B, and C--and you will be "safe". There probably is no such thing with lightning. Several different techniques are discussed--and a few of those posters even have experience with lightning. :cool:

    And our host's consolidated FAQ page:

    www.windsun.com
    Lightning Protection for PV Systems

    From other past posts here, Windsun (admin/owner of NAWS), he said that most of lighting induced failures he saw were in the Inverters' AC output section.

    Towards the end of this thread is a very nice discussion of proper generator grounding.

    -Bill

    Things like "not grounding" a Faraday cage probably does not make sense (or matter). A "proper" Faraday cage/shield--If you are inside, there is no way you can tell with test equipment what is going on outside of the cage--Grounded or not, etc...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nsaspook
    nsaspook Solar Expert Posts: 396 ✭✭✭
    Re: EMP and Solar System Protection

    A Faraday cage/shield is great for electric fields or EM radiation waves but they offer little protection from low frequency magnetic fields that happen in a solar flare. For this you need something like Mu-metal or Permalloy shielding plates to bend the field lines around what you are protecting. A soft steel shipping container works pretty well to shield low frequency magnetic fields and then you can build a proper Faraday cage inside it. ;)

    http://fas.org/nuke/intro/nuke/emp/toc.htm
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: EMP and Solar System Protection

    fyi, if you are in a steel shipping container, you are already in a faraday cage, but it will affect the magnetic waves as well due to the use of the steel.

    as was said, do things proper with grounding and use spds with lightning in mind and odds are you will survive a solar flare upwards of a carrington type deal. disconnecting things increases your odds of survivability, but if disconnecting with switches, fuses, and circuit breakers you have to keep in mind high voltages can jump past these and even through insulation at times depending on the voltage involved. you should know that flares aren't rare as they occur often. it is the large ones that are damaging to electrical infrastructure that are rare.
  • Steve961
    Steve961 Solar Expert Posts: 93 ✭✭✭✭
    Re: EMP and Solar System Protection
    niel wrote: »
    if you are in a steel shipping container, you are already in a faraday cage

    I'm not so sure about this. I've always heard that cell phones will not work in a Faraday cage. I tested this once by having myself fully locked into a shipping container and yet I was still able to make and receive phone calls while inside. How could this be? The vast majority of shipping containers have wooden floors supported by steel joists at 12" intervals or so. Could this be their weak spot?
  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
    Re: EMP and Solar System Protection
    Steve961 wrote: »
    I'm not so sure about this. I've always heard that cell phones will not work in a Faraday cage. I tested this once by having myself fully locked into a shipping container and yet I was still able to make and receive phone calls while inside. How could this be?

    Seams in the doors. If the seam is significantly larger than the wavelength of interest, you can radiate through it. All you need is a narrow seam.
  • Steve961
    Steve961 Solar Expert Posts: 93 ✭✭✭✭
    Re: EMP and Solar System Protection
    Seams in the doors. If the seam is significantly larger than the wavelength of interest, you can radiate through it. All you need is a narrow seam.

    So, with these seams, will a shipping container still function as a Faraday cage?
  • nsaspook
    nsaspook Solar Expert Posts: 396 ✭✭✭
    Re: EMP and Solar System Protection
    Steve961 wrote: »
    So, with these seams, will a shipping container still function as a Faraday cage?

    It depends on the required frequency range. For DC and long wavelengths it's effective in shunting magnetic fields as a bulk effect but at shorter wavelengths the higher resistance of steel increases the skin depth and reduces shielding at a given frequency over a good conductor along with other material effects that reduce it's effectiveness IRT a shipping container.

    http://www.ets-lindgren.com/pdf/emctd_1293_weibler.pdf
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: EMP and Solar System Protection

    Seams will radiate (and receive) at ~1/4 wave length:

    1 MHz = 246 feet
    10 MHz = 24.6 feet
    100 MHz = 2.46 feet
    1,000 MHz = 0.246 feet = ~3 inches

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
    Re: EMP and Solar System Protection
    Steve961 wrote: »
    So, with these seams, will a shipping container still function as a Faraday cage?

    At low frequencies, yes. If you seal the seams (conductive spring gaskets and the like) it will be a "true" Faraday cage, and work at most frequencies; in fact that's how they make anechoic chambers for RF testing.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: EMP and Solar System Protection

    Technically, an anechoic chamber is one that has "no echos".

    http://en.wikipedia.org/wiki/Anechoic_chamber

    You can have a Faraday Cage that is simple copper screening (or solid metal of some sorts) with well gasketed doors that blocks RF energy from outside (or inside getting out).

    An anechoic chamber has material on the inside that absorbs RF frequency so that it does not reflect all around the chamber--Makes it easier to tell were the RF leaks from equipment are coming from and / or to better measure antenna performance/patterns and such.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: EMP and Solar System Protection

    the faraday cage does not need to be solid metal everywhere. the shipping container will offer significant resistance to any infiltration at the frequencies of interest for this subject as we don't need to shield against microwave frequencies unless you want to shield against nuclear emps. just be sure good contact between sections is maintained and also with the doors and you've got a faraday cage. ground it of course as you want it at ground potential.

    bill's frequency list for lengths will vary as to the size of the conductors too as thicker and/or wider conductors will effectively lower the resonant frequency for the same length employed.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: EMP and Solar System Protection

    steve,
    the frequencies used by cell phones are fairly high up around 800-900mhz and by the spacings indicated by bill's calculations indicate it to be close to 3 inches and will be a bit larger in reality. this spacing on the container would certainly pass these frequencies nearly uninterrupted through any metal spacings greater or equal to the resonant point, but i'm also sure the container was not at ground potential either. in any case it will offer resistance even at cell phone frequencies though not eliminating it as it's path is not unimpeded everywhere. the lower frequencies will be greatly reduced if not eliminated and that's where most of the energy will be for the emp.

    the magnetic lines of force will be attracted to the steel and concentrated in and around the outside of it and depends on many factors as to what degree this occurs. thickness, length, and material used are the most common factors. if you've ever made a few nails into an electromagnet by winding wire around it that would be the proof of the tendency of the steel to be of magnetic ability. there are materials better at this for various frequencies, but for all intents and purposes it will work.
  • nsaspook
    nsaspook Solar Expert Posts: 396 ✭✭✭
    Re: EMP and Solar System Protection

    If you don't have space for a shipping container a simple metal trash can offers some protection if the devices inside are insulated from the skin by paper or non-conductive foam but it must be sealed correctly as the video shows.

    Attachment not found.

    DDP video.
    https://www.youtube.com/watch?v=y3S2KDuVxaU
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: EMP and Solar System Protection

    From the NOAA

    Space Weather Message Code: WARK06
    Serial Number: 246
    Issue Time: 2014 Sep 12 1535 UTC

    WARNING: Geomagnetic K-Index of 6 expected
    Valid From: 2014 Sep 12 1545 UTC
    Valid To: 2014 Sep 13 0900 UTC
    Warning Condition: Onset
    NOAA Scale: G2 - Moderate
    Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
    Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
    Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
    Radio - HF (high frequency) radio propagation can fade at higher latitudes.
    Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.


    We shall see what the impacts to various systems is on Saturday morning
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: EMP and Solar System Protection

    Oh no! It will take out my satellite Internet connection!

    But how will I tell if it's the geomagnetic event or just one of the normal, everyday system failures that plague all of our electronics from time to time? :p
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: EMP and Solar System Protection

    When the government sounds the town crier on a horse by our house? :p

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CDN_VT
    CDN_VT Solar Expert Posts: 492 ✭✭✭
    Re: EMP and Solar System Protection
    Oh no! It will take out my satellite Internet connection!

    But how will I tell if it's the geomagnetic event or just one of the normal, everyday system failures that plague all of our electronics from time to time? :p

    Look out your window , if Skytrain is moving , we could have a problem ;)
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: EMP and Solar System Protection

    it seems coot may have been taken out by it. he hasn't answered my email either.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: EMP and Solar System Protection
    niel wrote: »
    it seems coot may have been taken out by it. he hasn't answered my email either.

    Wasn't the flares that took me out but a flare-up. :p
  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    Re: EMP and Solar System Protection

    coot
    How did a tree fall on you?
    gww
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: EMP and Solar System Protection

    About two weeks ago, it was something along the lines of Pine Beetle infestation and a "widow maker" + Saw and not fast enough to get his leg out of the way when the butt end rolled his way. At this point, no broken bones but pretty beaten up and very sore.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    Re: EMP and Solar System Protection

    I hope I have better luck, big dead tree, uncles yard. I am glad it wasn't worse and I wish him good luck.
    gww