# From NASA scientist solar panels and an EMP



## budgetprepp-n (Apr 7, 2013)

A while a go I did a post on solar panels and a EMP trying to figure out what would happen to solar panels 
in use and in storage. SideKahr turned me on to a video made by a NASA scientist that does testing on EMPs.
He also gave me his email address (thank you Sidekahr) so I figured what the heck I sent him an email and asked.
What would happen to a solar panel in use and what would happen to a panel in storage?

Wow I got a response from him this what he sent back.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Hello budgetprepp-n

There is quite a bit of misinformation out there about EMPs. The question of solar panel susceptibility comes up almost daily, and the short answer is that no one has (to my knowledge) conducted EMP susceptibility tests on solar panels. That said, I have looked at this problem a bit, and I think I can provide a reasonable assessment.

Solar panels are basically an array of polycrystalline photovoltaic cells (used to convert light into electricity). Around each cell (or panel) is a bypass diode (typically Schottky-based). The diode is used to provide current paths around cells that are either under driven (in the shade) or defective. In addition, blocking diodes are used between the panels and the battery. These prevent the battery from discharging at night when there is no current flowing into them.

The PV cells themselves are designed to handle relatively high currents and may well survive an EMP. The bypass diodes, however, are not designed to handle large reverse currents or excessive high energy pulses and would very likely suffer damage. The array as a whole might continue to generate some current, but it would be far less efficient because the cells (or panels) without diodes would act to impede the flow of current. Worse yet would be if the blocking diodes fail. If even one blocking diode fails in a shorted condition, the battery would discharge it at night, making the system fairly useless. Likewise, if the blocking diodes fail open, no current could flow from the panel into the batteries, making the system completely useless.

If the panel is not hooked up, the only risk would be the radiated pulse (not the conducted that might find a way in on power lines). Chances of survival are certainly greater because the loop for current to flow to the batteries (through the diodes) is broken. That said, there are still small loops around each cell (or panel) that could introduce damage. It's hard to say for certain that they would be free of damage without testing, but I do think it's much less likely. If the panel is stored in a Faraday cage of some sort, of course that would greatly reduce the chance of damage because the radiated fields would be far lower.

Hope that helps,

Arthur

Oh, I failed to mention that in many systems, the bypass and blocking diodes are readily accessible. A very reasonable preparation would be to have spare diodes on hand in case of failure.

Arthur

And there you have it,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Wonder why if it comes up daily why no one has tested a panel to see?
I'm thinking of asking if I sent a small panel and low cost 30 amp controller if he would like to test it? ZAP!
this is the guy. Seems like a nice enough fellow.






By the way really nice 12 volt in line diodes are easy to find at the junk yard in older Fords


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## Auntie (Oct 4, 2014)

Great info. Thanks so much for sharing it.


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## A Watchman (Sep 14, 2015)

Good post.


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## SGT E (Feb 25, 2015)

I got hundreds of diodes from Signal diodes to 12 volt to 600 volt rectifier or "BLOCKING" diodes...Lots of ham radio operators do! As well as resistors...capacitors...transistors and tons of other junk in piles in every nook and corner.


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## 8301 (Nov 29, 2014)

Thanks BudgetPrepp-n

By chance I suspected that I had a blown diode in one of my larger panels the other day and popped the back cover off the box. The box is filled with silicone so I went on a solar site I visit occasionally to see if it was realistic to even try to dig out the silicone to gain access to the diode. Several people on the site had with much effort dug the diodes out but as often as not they then had to solder wires back they had damaged while messing in the silicone and only about half the time had they been successful in restoring the panel back to 100%. 

Still, I keep spare diodes and pray I never need to try to replace them.


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## cdell (Feb 27, 2014)

It seems like a reasonable prep would be lots and lots of electrical components. Diodes, capacitors, resistors.


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## Ronaldinyo (May 12, 2016)

I've been here less than a month & Sidekahr seems to be a respectable and honorable man! 

I know this wouldn't work for a solar panel...but I've heard that storing things in an unplugged microwave oven is one of the best ways to keep them from EMP damage.


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## A Watchman (Sep 14, 2015)

Ronaldinyo said:


> I've been here less than a month & Sidekahr seems to be a respectable and honorable man!


Someone check sideKahr's IP, I think he has set up a secondary account again.


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## budgetprepp-n (Apr 7, 2013)

Ronaldinyo said:


> I've been here less than a month & Sidekahr seems to be a respectable and honorable man!
> 
> I know this wouldn't work for a solar panel...but I've heard that storing things in an unplugged microwave oven is one of the best ways to keep them from EMP damage.


 yea,, He seems like a straight shooter but I would never say it where he could hear me.
His head would get to big for the posts


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## sideKahr (Oct 15, 2014)

budgetprepp-n said:


> A while a go I did a post on solar panels and a EMP trying to figure out what would happen to solar panels
> in use and in storage....Wonder why if it comes up daily why no one has tested a panel to see?


budgetprepp-n, my guess on why no one has tested photovoltaics is because there are so many varying construction methods by a lot of different manufacturers. Since the testing must be performed at multiple frequencies to be reliable, the task would become monumental.

Thank you for your work on this topic, bp-n. It's valuable information.


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## PaulS (Mar 11, 2013)

I have been gone a while and now you are getting misleading information from a NASA scientist about EMP resistant solar cells.
First, I believe he is talking about Solar EMP and not an HEMP. The two are very different. The solar panels are not likely to suffer much damage if they are not connected to the grid during a solar EMP. That is consistent with what I have learned about solar EMPs and the way they affect the grid. However... If the bomb that was dropped on Hiroshima was detonated at 150 miles directly above Omaha Nebraska every so9lid state device from Mexico City in the south to the Northwest territory in Canada to the north and from Boston in the east to Vancouver Island in the west would be useless unless they were shielded.

Everybody knows that an LED is a diode that makes light when you put a little power through it. If you connect that LED to a volt meter and point it at the sun it will make about 1/2 volt - almost the same voltage as a single photo cell from a solar panel. Each cell on that big solar panel is just a diode - a big diode but still a diode. It can handle a reverse voltage of about 200 volts like most other diodes and it has about a 1/2 volt drop across it when it is forward biased. The E1 pulse of a "standard" HEMP produces 50,000 volts per meter. Your 4 x 2 foot panel is going to be hit by just a bit over 65000 volts length wise. divide that by the 30 diodes that go from top to bottom and you have over 2000 volts across each diode. It doesn't matter whether the polarity is forward or reversed those diodes are going to be toast.

I am of the mind that it doesn't matter anyway because after an HEMP we will have three days of reasonably normal life followed by decades of getting to learn how to survive in the dark ages. No water, no fuel, no industry, no stores, no modern conveniences and none of the necessities that we believe we need to survive. There will be plagues, famine, death and on top of that we will get to witness the burning of every nuclear power plant in the USA because the motors that run the cooling pumps for the storage of used fuel rods are electric and the power plants can't run without the rest of the grid so with no power the water evaporates and the cooling pools begin to burn radioactive waste spreading nuclear fallout ever eastward. It won't be too bad in Washington state but the further east you go the more radiation and contamination you will have.

OK, enough doom and gloom! I will post the best inexpensive way to protect yourself and your electronics from an HEMP in another thread.
Have a great day!


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