Nissan Leaf 48v Off-Grid Solar Project

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Fukuokian said:
I needed to make custom solar mounting brackets for my Japanese tile roof. You might be able to buy them if your roof allows it, but in my case the rise between my roof decking and the space between the tiles is too small. Here's an example of some of the ones you can buy:

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Also, they're expensive (at least here). ($13-16 usd each) I need 20 so I put on my Macgyver hat and bought a bunch of these standard 90deg brackets (bottom of this picture below) and figured out how to bend them without an expensive brake press.

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The top metal strapping is the template I made by pulling off a tile and bending it to the dimensions I need. Then I made a bulky, poorly designed bender (🫣 which I'm not too proud of, but it worked for bending the 4 brackets I needed for my orginal 2 solar panels.)

Here's my new and improved diy brake press build... 🥳

1st, I repurposed a bench press adjustable safety catcher.

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Then off to the hardware store for < $6 usd in metal parts and screws. Using some scrap wood I built this guillotine looking contraption. The flat metal is sandwiched and bolted between two pieces of scrap angle iron I had. I ran the side pieces of wood through a table saw to make cuts to act as guides. I made the bottom piece of wood with two 45degree cuts on the table saw and fitted the 90degree metal piece and screwed it in.


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I added two guides and a spacer to hold the bracket for the first bend.

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Then a 5Ton bottle jack does all the work.

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I can turn the bracket around and do the second bend from the opposite side.
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Really a great idea! 😊 And maybe simpler than my method with angle brackets and screws and nuts.

Is it possible for you to make a video of this process?
 
kje said:
Really a great idea! 😊 And maybe simpler than my method with angle brackets and screws and nuts.

Is it possible for you to make a video of this process?
Click to expand...
Actually, I would have preferred using your method; however, I couldn't find the correct size that would work with my tiles/roof.

Sorry, I did all the bending already, and have the bottle-jack somewhere else now. But, I'll toss in a few more pictures:

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kje said:
It's also possible to use treated lumber (wood/plank/barge) as mounting rails for solar panels on the roof like I did.

I made a thread about it for some time ago:
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Hi kje,

I initially looked into using pressure treated wood, but found it isn't often used on roofs in Japan. It is used for ground based panels where it can be monitored more closely.

It won't meet various codes/regulations (for wind, fire and earthquake) in many regions of Japan.

Wood will expand and contract with humidity and can warp. Fasteners can loosten for the same reason.

If the pressure treated wood uses copper azole, it is reactive with aluminum used for solar panel frames. It requires some barrier between the two.

I really wanted to use wood because it is so much cheaper, lighter and easier to work with. I even considered switching to ground-mounted panels, but I don't want to give up the space, or have longer cable runs.
 
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Hey folks - since the general topic (metal vs wood) came up it reminded me I used pressure treated 2x4s for part of the mounting of a couple of panels on my pergola. Here's what it looks like after 8 yrs (we live in Zone 4 weather). Not bad shape / not seeing structural issues but of course the 2x4s are well protected by the panels.
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Not pushing any particular solution, just sharing that on my roof I went aluminum rails. I have cement tiles... so between tile 50yr est life and metal rails (?yrs life) and 30yrs? panel life - I'm hoping never to go up there again.
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I notice @Korishan went metal for his ground array as well :)
 
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OffGridInTheCity said:
I notice @Korishan went metal for his ground array as well :)
Click to expand...
Yeah, mine was made from basically "scrap" metal. Good thing is that I didn't pay for any of it, just had to buy the nuts/bolts to put everything together.
 
Brackets & rails painting time!

If anyone is in Japan, this paint is really good for metal... (from Handsman - may need to use some thinner... it's really thick. )

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Needs one more coat and some touchups.. (y)
 
*** Check out this post by Korishan *** I decided it will be a good idea to add a H2 sensor to trigger the temperature controlled vent fans.

Working on the battery box...

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Cut two holes in the box... one down low, and the other high up, kitty-corner. The upper one will have a temperature controlled fan.
It should provide good cross-ventilation.

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But foam tape around the vent, basically to hold the silicon sealant in place while it dries.
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I used aluminum tape to seal the insulation, then a ring of brown duct tape to protect the aluminum when the vents are inserted.
The walls are 4.5cm thick, so I had to MacGyver the mounts by cutting the 3 tabs and bending them so they can screw into the aluminum
wall panel. Not pretty (from the inside) but functional. I'll appy some foam sealer in the gaps later on.
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Cleaned the floor, and used pre-primered/sealed plywood layed upside-down and made cutouts for the corner drains.
I figure the primered side will do more good facing down in case there's ever any condensation.

The plywood will help distribute the weight of the batteries. I also added extra spacers/supports under the box. You can see
three of them under the front of the door. (There's around 20 of them in total.)

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I wired up a 12v car halogen bulb to discharge any of the modules that are too high a voltage, so they can all be paralleled together before making the final battery configuration. (7 stacks of 20 modules) It's an easy/cheap way to do it, if you don't have a charger/discharger; but it would take way to long if the voltages are too far apart.

The first 91 modules (from 2 leaf batteries) have already been paralleled together, and have stayed within .01v of each other after sitting for more than a year. However, I need to verify the last 49 modules are close enough before parallel balancing everything.
 
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