piezo effects of solar panels and lightning?

Beau Schwabe

So I was fortunate to come across 1250 Watts of solar panels recently ( free to me ), but when looking for their current market value and a grid tie inverter to accompany them, I stumbled across a phrase that mentioned "piezo effects of lightning" and how a particular grid tie inverter had built in protection against high piezo electric voltages that could be produced by lightning. .... Most likely hog wash, just to gain a bogus selling point.

Anyway, we have a storm rolling through right now, so I thought I would just connect my scope... The highest voltage that I have observed is about 5V, and that was from a pretty large lightning strike. Nothing in the way of piezo effect though, this reading was simply from the amount of light that the solar panels picked up. The shock wave from the lightning that /might/ causing any piezo effect is not perceivable on the scope.

Has anyone else heard of this? I mean I guess in some cases it might be plausible, but not to the point it would cause any noticeable problem, especially with a load.

kwinn

I suspect you are right about the hogwash, although there can be spikes high voltage spikes (KV range) on the power lines that are of such a short duration (picoseconds) that they are extremely difficult to see with a scope. As far as any “piezo effect” from lightning, the only effects I can think of would be from the light, the sound from the thunder clap, and the emp from the high current pulse. Can't see any of those causing much of a spike unless the lightning hit the actual panel. In that case any built in protection would be toast.

jmg

Beau Schwabe (Parallax) wrote: »

..I stumbled across a phrase that mentioned "piezo effects of lightning" and how a particular grid tie inverter had built in protection against high piezo electric voltages that could be produced by lightning.

Has anyone else heard of this?

I would suspect some English -> Chinese -> English translation got into the mix here.

If you remove some words, it makes more sense :

["how a particular grid tie inverter had built in protection against high voltages that could be produced by lightning."]

I recall a washing machine solenoid that fell victim to lightning. On removal, the fine winding wire had nicely fused between the terminal and coil, which shows some of the induced energies involved. It must have flashed over, to avoid the inductance.

Of course, a direct strike is much more spectacular, but a lot rarer.

It is good advice when leaving remote locations like holiday homes, to unplug appliances.

LoopyByteloose

Wouldn't the piezoelectric effect not be from the electricity of the lightning, but the shock-wave of the thunder hitting the panel that is on the roof?

Or is it possible for a spike from a lightning strike on the mains to travel into the panel and crack the panel due to a piezoelectric pulse?

But, it would be easier to just say, "No warranty implied for damage due to any acts of nature, including thunderclap or directly lightning strikes." But then they wouldn't be able to sell you a 'snake oil' add-on product.

Reminds me of why cowboys never pee on a fence post. A lightning strick 25 miles away might be traveling down the barbed wire at that very moment.. But that is 'pee-so-electric'.

Tor

A reasonably close lightening strike can induce enough current into cables to fry your system. In a particularly lightning-prone area we've had three of our boards fried due to lightning strikes. There are only two such sites (among our customers) anywhere in the world that this keeps happening though, but it's all about how close the strike is. Fortunately only the differential transceivers burn out most of the time (although they would be totally fried) so it's usually possible to repair the boards.
One time I visited a particular customer there was a terrible thunderstorm (had to wait inside the airplane for 1.5 hours before they would let us out) and not only was the board fried when I arrived there, their brand-new $20K control unit was all gone too. That wasn't our tech, but what they had in common was signal cables connected to the system. The only way to protect the electronics under such circumstances is to completely disconnect everything and keep the cables and boards separate. Protection circuits are mostly too slow.

Of course the ultimate one wasn't due to lightning, but a solar flare in 1859 where enough current was induced into telegraph wires to bring down communication lines both in America and Europe.

-Tor

bill190

Having never heard of this before, I consulted the all knowing google and found something interesting. That is energy harvesting and "piezoceramic solar panels" which apparently create electricity from ambient sounds/vibrations as well as light.

So maybe that grid tie feature is for those types of panels? Or for such a problem which might exist in the future, but not common now?

Anyway google the words...

piezoceramic solar panels

or...

piezo ceramic solar panels

prof_braino

Loopy Byteloose wrote: »

Reminds me of why cowboys never pee on a fence post. A lightning strick 25 miles away might be traveling down the barbed wire at that very moment.. But that is 'pee-so-electric'.

I knew it had something to do with barbed wire, I hadn't heard about the lightning. That's for the info. Ouch!

LoopyByteloose

bill190 wrote: »

Having never heard of this before, I consulted the all knowing google and found something interesting. That is energy harvesting and "piezoceramic solar panels" which apparently create electricity from ambient sounds/vibrations as well as light.

So maybe that grid tie feature is for those types of panels? Or for such a problem which might exist in the future, but not common now?

Anyway google the words...

piezoceramic solar panels

or...

piezo ceramic solar panels

Now that you mentioned piezoceramic, I seem to recall an idea of having solar panels along freeways provide lighting and harvest electricity both from the sun and noise.

revalea75

Thanks for share this information.