# Protecting Solar Panels and LED Lights from EMP?



## john10001 (Mar 20, 2013)

For those who have backup solar panels for emergency lighting or off grid energy and thinking ahead for WTSHTF scenario, how are you planning on protecting against potential EMP?

Am I right in believing that an EMP will only take out all electronics not shielded at the time and those particularly sensitive to this such as the diodes in Solar Panels and LED Lights?

If so, I realise that some have backup Solar Panels buried as a backup. What about Solar Panels and LED lighting you have in use at the time? Do you think it possible to just take the hit and have a bunch of diodes to replace inside the Solar Panels after any potential EMP? E.g. solar flares, advanced weaponry for economic war etc?

I figure LED light blubs eventually will come down further in price and it will not be difficult to have a load of spare bulbs for your lighting should the ones you're using be taken out by an EMP. For those with Solar Panels though who can't afford to buy spare panels to bury I am thinking this is the alternative?

If this is the best alternative then would be interesting to know what type of diodes are used in solar panels so people taking this route can buy a bunch of them and shield them away somewhere safe along with spare LED bulbs.

Thanks for any advice on this!


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## Prepadoodle (May 28, 2013)

An EMP is a magnetic wave. Whenever magnetism moves across a conductor, it basically pushes electrons along that conductor, and it's this electron flow (current) that will sizzle your stuff. Wiring acts like an antenna, and the longer the wire, the more damage you can expect.

The individual cells contain fine wires and are connected together by thin conductive ribbons. I don't have any hard data on this, but it probably wouldn't take much current to melt some of these wires. Your bigger issue, however, might be the inverter, charge controller, or whatever else is in the system. Arrays are usually connected to the rest of the system with long, fairly heavy cables, and these are ideal antennas.

You probably won't have enough warning to disconnect your controllers, so there probably isn't much you can do to protect them. With solar now available for about 85 cents a watt, it's not that expensive to have backups, but the balance of system parts are still kind of pricey.

To answer your question though, many manufacturers use Schottky-type bypass diodes. I would contact the manufacturer and get exact replacement specs. I would avoid the newer style "active" bypass panels which use MOSFETs, which are very sensitive to stuff like this.

I would also go with a redundant modular setup. For example, rather than getting a 3,000 watt inverter, I would look at getting 6 X 500 watt ones, and rig them up so they were disconnected when not in use. I would have one on all the time for the refrigeration, for instance, and maybe one for lighting. The others would be manually switched on only when needed, and since they would be electrically isolated when off, would be more likely to survive a hit.

There are many levels of EMP. It might be impractical to protect against the worst possible case, but we are far more likely to see a weaker pulse. In any low to mid level EMP, your panels might make it through, so having some extra parts on hand isn't a bad idea.


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## PaulS (Mar 11, 2013)

The diodes themselves (even one sitting on a shelf with nothing connected to it) will be destroyed by an E-1 pulse from a nuclear detonation at high altitude (above 50 miles). The only way to protect them is to have them encased inside a copper or aluminum box that is insulated on the inside. The more laters you have the better the protection. Burying them without the "faraday cage" is of no value. 
For individual components you can place them in a "zip-loc" snack bag, wrap that in heavy duty aluminum foil, (all seams rolled not folded) Place that into another bag and wrap that in heavy duty aluminum foil, do this so you have at least 4 layers of foil and then place the individual packs together in a bag and wrap that in foil then place it in a garbage bag and place it into an aluminum pot (cheap cookware will work) and tape the cover in place with aluminum tape.

You should use the same level of security for any electronics that you want to be in workable condition after a nuclear EMP event.

Your electronics are not effected by the relatively low frequencies of the E-3 pulse that solar flares and coronal mass ejections cause but if they are connectd to the grid the high voltages can destroy them if you do not use a good surge suppressor in-line.

Keep in mind that just a 6.6 foot (2 meter) cord can carry over 100000 volts from an EMP event so panels on the roof with long wires will be effected by high voltage spikes from any EMP. The standard reverse blocking voltage of the type of diodes which are used to make electricity is only 200vdc - anything that high or higher can burn out individual diodes making your panels worthless without rebuilding them.


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