lightning and PV systems

[buddog]

I expressed my interest in a PV system here in an earlier post. Since then I have found a local fellow here with nice system. He was kind enough to take time from his busy schedule to show and explain the system to me. 2200W PV another 750W wind, battery storage and propane generator back up. He is off grid. Told me he got hit by lightning last year and had alot of damage. I doubt this is a common problem maybe Bob can shed some light on this. Seems a lighting rod would be a bad thing here unless it was closse by on a seperate structure. Any thoughts?

[Bob Boyce]

Lightning is a very real danger in solar power, as well as any type of electrical installation.

Bob

[12volt dan]

Was he properly grounded? I've been hit (through the windmill) but sustained little damage

I chalk that up to luck mostly but I can't emphasise properly grounding a system including the batteries and I like the idea of a seperate ground for them. Just to avoid any link to any other high point. It could backfeed from say the windmill ground to the batteries and fry them if they're on a common grnd

Just my 2 cents

[buddog]

Yeah Dan it should have been well grounded, 2 ground rods driven down 8 feet and connected with heavy copper cable. Panels were mounted on a heavy angle iron frame supported by steel pipe, this could have been a factor also. We get some really big storms here in the midwest. Could have been a fluke. I only brought this up to see if anybody has a good idea for protection, due to the substantual investment in money, time and effort. I was thinking of a steel pipe say 20 to 30 feet tall with a lightning rod, near but not to close. Lightning does some strange things around here. I had a wall mounted telephone blown to bits by a strike but only scorched the wall. Sure was exciting at 3AM though.

[12volt dan]

I'll bet heh heh heh

My hit came down the windmill feed skipped the batteries,set off the circut breaker on the inverter and fried the power supply for the laptop without harming it (laptop)

On the bright side I found out that the laptop would work fine on 12volt directly from the batteries instead of buying a new power supply at 15 volts. I call it timex now. It's relegated to a car diagnostic tool but it worked fine (and still does) for 3 years till the modem quit. Now I have a new Dell that wants 19 volts. I haven't tried 12v on this one yet

[Bob Boyce]

When I cut the pad for my house out of the side of the slope leading back to the top of the ridge, I had to carve into rock quite a bit. For this reason, grounding may be more difficult for me. I have some minor fill on top of the rock to allow levelling ect, but not a lot.

I would love to ground the heck out of my system. Will drive ground rods at the metal shop building, at each corner. They may end up being short because solid granite is only down a couple of feet back there.

When I dug out front for the septic tank and underground LP tank, I had to dig a trench 6' deep into the granite, so I placed my array pole centered between the two. I will drive at least one grounding rod at the array. I may end up having to lay out buried radial wires in all directions terminating in a circle of shorter ground rods in order to get a decent lightning ground.

Bob

[buddog]

I have that rock problem on my place too. Sandstone. When I grounded the box in my pole barn I had a heck of a time driving down 4 feet, I like that radial design you have.

[12volt dan]

[Bob Boyce]

[Bob Boyce]