pseudo_mccoy
Well-known member
(I'm not familiar with cross-post etiquette, so I hope this is alright)
I'd like to expand on an idea I brought up in william_k's thread, “Stealing Solar Panels.” As I mentioned over there, I made a lockable aluminum/polycarbonate lid for my portable solar panels. I did this for two reasons.
1) I have trust issues. However, it seems my paranoia may not be shared by the community on this one. It seems everyone in the other thread thinks no thief would have the gall or ability to unbolt and remove a solar panel from a vehicle. That's a fine view to take on the subject. It just doesn't suit me. Or at least it didn't suit me back when I made the thing. If I could go back, I'm not sure I'd do it again. All the same, I'm writing this in the event that someone could perhaps use/improve the design.
2) I wanted to be able to open the lid, take out the panels, set them in the sun, and park in the shade. Great for boondocking, right? Not so great for where I'm at currently, though. For urban environments, I wanted to be able to secure the panels to my van. Lastly, I wanted to be able to remove everything (super stealth mode ftw!). The whole thing is mounted to rain gutters, so I should be able to manage that, except I'd have to undo some red loctite to do so. I've never done that. Is it hard?
Ok, so I needed a lid that can both swing up as well as lock down. I used u-bolts and bike locks to make this happen. As you can see in the pictures below, the lid is held to the safari rack by two u-bolts on the forward facing side. The rear facing side has the bike locks.
Bob brought up a good point when he mentioned that the lid could cause heat to build up and degrade the panels' output. I checked with my good buddy, google, and of course he's right. Here's what I came up with:
“...heat is probably not going to break a panel. However, the loss of efficiency for a specific panel can be found using something called a temperature coefficient or "Pmax." (http://www.civicsolar.com/resource/how-h...ficiency). This is supposedly provided by the manufacturer.
I'm terrible at math, but the article I linked gives an easy example for one of their panels. It says that for every degree (Celsius) the temperature increases, the panels' efficiency decreases by about half a percent. I won't really understand what that means until I run the numbers for myself.”
Another bad thing about this design is that the polycarbonate (lexan) sheet itself reduces the panel's efficiency by something like 20%. I'm hoping that this is OK because the panels are 120 watts but I have only 70 ah of batteries. Here's my reasoning: Let's say the heat and lexan together account for a 30% efficiency loss. That means up to 84 watts are still reaching my little battery bank, right? Since we're supposed to have a roughly 1:1 ratio between panel and battery, I think I'm in the clear.
I took these pictures this morning on my way to the library. Ever since I landed in the pacific northwest, I've been worried about the constant cloud cover, so when the sun miraculously made an appearance, I pulled over immediately to try (for the first time) to reposition my panels and catch all the rays I could. Unfortunately, I could tell this drew some attention. One guy in a car pulled up right beside me and openly stared at me. I waved. He waved, then left. It was encouraging to know folks are concerned about a scruffy dude trying to pull a solar panel off a van : ) This might support those who think a thief could not get away with it, but who knows if anyone would actually take action. Also, I think several vehicle dwellers made a pass to check me out. I wasn't aware the area was in use by fellow dwellers. Had I known, I would have picked a different spot to work.
Overall, I was a little disappointed at how long it took me to jimmy the thing open and pull out the panels. By the time I managed to get them mostly off, the sun was gone. But that was ok because I took the opportunity to clean/service the apparatus, which it needed.
I'd like to expand on an idea I brought up in william_k's thread, “Stealing Solar Panels.” As I mentioned over there, I made a lockable aluminum/polycarbonate lid for my portable solar panels. I did this for two reasons.
1) I have trust issues. However, it seems my paranoia may not be shared by the community on this one. It seems everyone in the other thread thinks no thief would have the gall or ability to unbolt and remove a solar panel from a vehicle. That's a fine view to take on the subject. It just doesn't suit me. Or at least it didn't suit me back when I made the thing. If I could go back, I'm not sure I'd do it again. All the same, I'm writing this in the event that someone could perhaps use/improve the design.
2) I wanted to be able to open the lid, take out the panels, set them in the sun, and park in the shade. Great for boondocking, right? Not so great for where I'm at currently, though. For urban environments, I wanted to be able to secure the panels to my van. Lastly, I wanted to be able to remove everything (super stealth mode ftw!). The whole thing is mounted to rain gutters, so I should be able to manage that, except I'd have to undo some red loctite to do so. I've never done that. Is it hard?
Ok, so I needed a lid that can both swing up as well as lock down. I used u-bolts and bike locks to make this happen. As you can see in the pictures below, the lid is held to the safari rack by two u-bolts on the forward facing side. The rear facing side has the bike locks.
Bob brought up a good point when he mentioned that the lid could cause heat to build up and degrade the panels' output. I checked with my good buddy, google, and of course he's right. Here's what I came up with:
“...heat is probably not going to break a panel. However, the loss of efficiency for a specific panel can be found using something called a temperature coefficient or "Pmax." (http://www.civicsolar.com/resource/how-h...ficiency). This is supposedly provided by the manufacturer.
I'm terrible at math, but the article I linked gives an easy example for one of their panels. It says that for every degree (Celsius) the temperature increases, the panels' efficiency decreases by about half a percent. I won't really understand what that means until I run the numbers for myself.”
Another bad thing about this design is that the polycarbonate (lexan) sheet itself reduces the panel's efficiency by something like 20%. I'm hoping that this is OK because the panels are 120 watts but I have only 70 ah of batteries. Here's my reasoning: Let's say the heat and lexan together account for a 30% efficiency loss. That means up to 84 watts are still reaching my little battery bank, right? Since we're supposed to have a roughly 1:1 ratio between panel and battery, I think I'm in the clear.
I took these pictures this morning on my way to the library. Ever since I landed in the pacific northwest, I've been worried about the constant cloud cover, so when the sun miraculously made an appearance, I pulled over immediately to try (for the first time) to reposition my panels and catch all the rays I could. Unfortunately, I could tell this drew some attention. One guy in a car pulled up right beside me and openly stared at me. I waved. He waved, then left. It was encouraging to know folks are concerned about a scruffy dude trying to pull a solar panel off a van : ) This might support those who think a thief could not get away with it, but who knows if anyone would actually take action. Also, I think several vehicle dwellers made a pass to check me out. I wasn't aware the area was in use by fellow dwellers. Had I known, I would have picked a different spot to work.
Overall, I was a little disappointed at how long it took me to jimmy the thing open and pull out the panels. By the time I managed to get them mostly off, the sun was gone. But that was ok because I took the opportunity to clean/service the apparatus, which it needed.
