Somewhat OT: Solar panels on shop roof

[neilho]

I have a standing seam roof. No way in hell I’d clamp all that crap to it. The roof metal is very thin and only lasts because of the coating. I’m not buying the idea that clamping to the seams doesn’t damage the coating.

You might change your mind if you saw the clamping mechanism. It's a large setscrew with a radiused tip pressing into a matching recess. The aluminum version provides the proper electrical relationship to the standing seam material, be it galvanized or galvalume. Grease is helpful, too.

I've installed a few of these clamps, inspected a 10 year old installation that hadn't been properly torqued. There was damage to the top of the seam where the clamp had shifted (high wind loading) but I didn't see any rust or damage to the coating from the clamping. It was old-style hot dip galvanized, dunno what your coating is.

Around here (central VT) it's the preferred installation. The PUC (the state regulator here) prefers roof mount systems, 12/12 standing seam is the traditional roof and pitch, which just happens to be the recommended solar angle here. No roofing penetrations is a huge plus. I agree, it's not ideal, but damn close.

Unirac S-5 is the setscrew version (and the oldest) but SnapnRack is a newer version that clamps to the seam without distorting it. You might like that better.

 

[Pete Deal]

You might change your mind if you saw the clamping mechanism. It's a large setscrew with a radiused tip pressing into a matching recess. The aluminum version provides the proper electrical relationship to the standing seam material, be it galvanized or galvalume. Grease is helpful, too.

I've installed a few of these clamps, inspected a 10 year old installation that hadn't been properly torqued. There was damage to the top of the seam where the clamp had shifted (high wind loading) but I didn't see any rust or damage to the coating from the clamping. It was old-style hot dip galvanized, dunno what your coating is.

Around here (central VT) it's the preferred installation. The PUC (the state regulator here) prefers roof mount systems, 12/12 standing seam is the traditional roof and pitch, which just happens to be the recommended solar angle here. No roofing penetrations is a huge plus. I agree, it's not ideal, but damn close.

Unirac S-5 is the setscrew version (and the oldest) but SnapnRack is a newer version that clamps to the seam without distorting it. You might like that better.

Well not likely. There's nothing going to convince me that putting all that crap my roof, any roof, is a good idea. The roof and foundation are the most important parts of the house. Having a bunch of monkeys running all over it installing a bunch of soon obsolete electronics isn't a good idea. In my case It also doesn't help that I think the whole solar panel thing is just a government funded boondogle. If it was good you wouldn't need me to help you pay for it.

 

[gustafson]

Well not likely. There's nothing going to convince me that putting all that crap my roof, any roof, is a good idea. The roof and foundation are the most important parts of the house. Having a bunch of monkeys running all over it installing a bunch of soon obsolete electronics isn't a good idea. In my case It also doesn't help that I think the whole solar panel thing is just a government funded boondogle. If it was good you wouldn't need me to help you pay for it.

Face it you are not going to be convinced no matter what

On topic, do your roof first, My garage is going to need a roof so I am investigating solar installs.

 

[neilho]

Well not likely. There's nothing going to convince me that putting all that crap my roof, any roof, is a good idea.

You don't have to. You can build a carport like Doug suggested or do a groundmount install. Easier to clear snow, too.

The roof and foundation are the most important parts of the house. Having a bunch of monkeys running all over it installing a bunch of soon obsolete electronics isn't a good idea.

Guaranteed output for 20 years. It'll outlast the electronic thing you typed your answer on by at least 5x.

In my case It also doesn't help that I think the whole solar panel thing is just a government funded boondogle.

Think some more. Has to do with government priorities. We pay for war/military/peacekeeping (however you want to think of it) because the government, voted in by us, voted it in. That's quite a bit more money than solar tax credits. Also roads, bloviators in Congress bailing out their buddies on Wall Street. Just some for-instances.

If it was good you wouldn't need me to help you pay for it.

Works the other way too. Nobody's forcing you to take the money and there's no guarantee that it's available to you anyway. Running the numbers, your numbers, is the only way to know if it's "good" for you.

My electricity costs 23 cents /kWh after the first 100kWh/month. $30/month service fee. Typical monthly bill is over $100. Bought 6kW of used panels and an inverter for $2K, it'll pay for itself in 2 years. No tax credits available for used equipment, BTW, and I don't make enough money to take the tax credit.

Maybe best to figure out if it works for you and if not, live and let live?

 

[hanermo]

My (large) 10 kW PV system installed on my roof is half paid for, about 1 yr, and when/if the subvention is approved is free.
1.5$ / KW, worst case, 0.8$ cost with subvention -- 15 kW peak 3-phase inverter.
The electrical savings are about 4000€/r.
Electricity is much more expensive due to the ukraine stuff.

Next week I hope to install 6 new diffusers with 2 x 8 kW heat pumps, and this should reduce my past 3000 €/yr heating oil bill to somewhere near 200 €/yr.
The oil savings are about 3-4000€/yr.
Oil is much more expensive due to the ukraine stuff.

More than the savings, I pump about 4x the power I use into the electric grid, reducing loads, reducing need for local transformers, reducing grid usage, for trivial compensation. About 0.02 $/kW.
It´s a win-win.
The power company takes most of the profit, but I also get about 7000 € in savings per yr, about my total net cost.

 

[DouglasJRizzo]

A friend has just done this on his shop roof. Put the new roof in, then the panels on top. Made a difference in his electric bill, for sure.

 

[Bill D]

Saw this today. Lots of irrigation canals in the central valley. But they run scoop loaders in them every winter to clean them out.
Bill D

California to install solar panels over canals to fight drought, a first in the U.S.

California will be the first state in the nation to install solar panel canopies over canals to combat drought and climate change.

www.cbsnews.com