the " big solar flare" and PV

Re: the " big solar flare" and PV

BB. wrote: »

We have had some discussions here:

Making a PV system survivable in EMP/CME conditions?

Short answer, for Solar Flares, off grid power systems are just too small to "receive" the energy from the sun and be damaged.

Harden your system against lightning damage the best you can and have some spares available--Much more likely than an CME or EMP for the average user.

-Bill

HUH???

What would the GFCI do? My understanding an EMP pulse would be picked up by any wires attached like even the Ground wire?

Re: the " big solar flare" and PV

waynefromnscanada wrote: »

Methinks Dave is making funny ;)

It is both a funny and an urge for anyone who might be building an inverter to design it as Xantrex did. No matter if the signal to shut down an inverter comes from a GFCI or an Arc fault it is always better if the system shuts down and protects the loads. Depending on how close or how powerful the lightning strike or EMP is might make the difference. Direct experience here!

This is the only reason I have disagreed with you folks here about GFCI. We went thru this on the Xantrex forum when their first MPPTCC came out. At the time I had a client who was upset that the system shut down during a close strike. There was talk of allowing the user to decide (Telecommunications). Now after years of direct experience with a blown 1 amp fuse and a functional system after lightning I know it is a good thing! Sometimes there is not anyone home to shut down and I "know" this has helped.

Definately not saying that this will save you from EMP or Lightning. Definately saying that it is always a good thing to shut down a system during lightning. Even all wiring disconnected by over 8 feet will not help when your number is up. For people offgrid and remote, circuit protection that does something useful is a value even if it bonds earth to DC negative thru a 1 amp fuse and monitors via xanbus.

As for the funny part, I would say that Xantrex was told to advertise this and it never happened....

Re: the " big solar flare" and PV

BB. wrote: »

Here is another engineering based article about shielding against CME/EMP events.

-Bill

Good information, the best offense is a good defense. (A very good ground system)
I worked at a place once a long time ago that was completely EMP proof. Double Faraday cage with it's on internal power feed from a motor/generator and backup UPS set separated by a insulated power shaft to the generator inside the room. It was a doomsday TACAMO communications vault. It was also a good place to get some sleep while on watch.
http://en.wikipedia.org/wiki/TACAMO

Re: the " big solar flare" and PV

Transformer saturation from CME events is another reason utilities are going HVDC for long transmission interties but even with DC lines you have the problem of commutation failures from excess current.

The Pacific HVDC Intertie: We power LA.
http://www.abb.com/industries/ap/db0003db004333/2a5cad2346b4378ec125774b002a16b6.aspx

Re: the " big solar flare" and PV

Its only a brief spike from a CME that occured a few days ago. Spikes of 3-4 happen all the time. http://www.swpc.noaa.gov/rt_plots/kp_3d.html

Re: the " big solar flare" and PV

Peter_V wrote: »

Kind of depends on where you live. From the research I've done the vulnerable locations (in the USA) are the northern states and along the coastlines. Central/southern states shouldn't see much if any effect. Plenty of power company stations up the line will disconnect the impulse before it reaches those of us in the south.

I'm not worried, but If I lived in the north or along the coast, then I'd probably get a backup inverter and some batteries just in case.

i disagree with it's a matter of where you are unless it is a case of you are on the other side of the world at the time of the event and the earth itself somewhat shielded you from it. now it would be as bb said unless you are miraculously spared damages because of a failure up the line on the grid making the smaller area of utility lines present in your area not as absorptive of the event. if not this then you must be in total isolation or take a big chance that the event won't do your gt connected stuff harm. most relays and switches will normally be engaged at the time of the event unless you disconnect. will it jump it even then? it may or may not depending on the energy of the event and how much reached you. the time of day, and to a point the season, will impact how much of the event hits you. this event will not be all that very different from the south to the north or the east to the west for mainland u s a as pretty much all utility lines will be hit from the sky and has nothing to do with populations or remoteness from coasts or population centers you are as it does not originate in those areas. bb is quite correct that it could jump breakers, fuses, and switches if powerful enough, but i think you stand a better chance of possibly being spared if physically pulling the fuse or shutting the switch or breaker off if you got enough warning of the event. also spd usage will further increase the odds and remember spds can be used on a service entrance breaker box too. if the spd is at your main cb box and the breaker is opened to the inverter you stand a much better chance of that energy being directed to ground and far less likely to jump the gaps to your inverter. plus if you have an spd on the output side of the inverter before the breaker it increases the odds there too on grounding out any energy leftover that may have still jumped the gap as some of that energy was already diffused to a point in the main cb box with an spd.

to summarize this, it is true that odds are you could still be screwed, but there is not a guarantee that you are either and the more steps taken and the more isolated you're backup power setup is, the better your odds will be.

about the only way to insure against all events would be to put the stuff into one of those metal shipping containers and bury it deep in the ground with no inputs or outputs going to and from it. i don't see any reasonable person going that far though.

Re: the " big solar flare" and PV

http://earthsky.org/space/strongest-solar-radiation-storm-in-7-years-expected-january-24

Re: the " big solar flare" and PV

peter,
my point was that southern states will still be prone to a big event as i do not want anyone in southern states to feel they are protected from this. solar storms push our magnetic field that faces the sun inward toward the earth. i did acknowledge that there would not be huge differences between areas, but yes there are some differences. when it comes to texas being too far from say north dakota it isn't a big difference or the same as from the equator to the poles as the differences aren't as much as you think within the u s a, but differences they are.


the rear would appear like a teardrop with a tail that extends far out and would add a bit of insulation for those on the backside of the earth, but you are correct here that even back there it is possible to get some of that energy. i also agree the poles get hit the hardest.

the oceans will not cause coastal areas to be prone as that is like a giant ground for such an event for what hits the ocean will not be sent back out to go to coastal cities. it is another matter if we are talking of an event making its way through a coastal area to get to the ocean as you'd have to be in a faraday cage then.

Re: the " big solar flare" and PV

HMm tat one says X18 this one says X5 CME http://www.spaceweather.com/

?? that seems to be a large variation... still it happened

Re: the " big solar flare" and PV

well, it initially hit about 6am et and we're still here with no problems up until now. true, it isn't over yet, but indications are that it was overblown in it's intensity even though it was still 10x stronger than most flares on average.

http://news.yahoo.com/biggest-solar-storm-years-hits-far-good-162342753.html