Sun Inspired: How To Build A Solar Backpack Even before the economy tanked, interest was growing in the do-it-yourself movement. Here, a look at how to make your own solar backpack — something that anyone with a portable electronic device like an iPod could use.

Sun Inspired: How To Build A Solar Backpack

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Even before the economy tanked, interest was growing in the do-it-yourself movement. The DIY ethic embraces the notion of recycling and repurposing objects, snatching things headed for landfill and making them useful again. So today we're going to learn how to make something that anyone with an iPod would find useful. And our guide is Jon Kalish.

(Soundbite of music)

JON KALISH: I'm walking to the subway stop near my loft in Manhattan listening to my favorite podcast.

Mr. MIKE O'CONNOR (GeezerCast): Hello again, Mike O'Connor, another GeezerCast for you.

KALISH: When all of a sudden, the battery in my iPod conks out. This is annoying, so I detoured to an electronics store in Brooklyn called Digital Fix, where they sell a knapsack equipped with a solar charging system that would've kept my iPod playing.

(Soundbite of music)

KALISH: When I get there, owner David Auerbach shows me the backpack, which has three solar panels and can charge iPods or cell phones. It's nice, but a bit pricey.

Mr. DAVID AUERBACH (Owner, Digital Fix): This one is $200 and it doesn't sell well.

KALISH: Do you have a sense of how many of these you've sold?

Mr. AUERBACH: Under 10, and we've had it for two years, so not a big seller.

KALISH: I wonder if you can make one of these yourself.

Mr. AUERBACH: You definitely could. You can make anything, you know.

KALISH: He got that right.

(Soundbite of music)

KALISH: I've done quite a bit of do-it-yourself furniture making, much to the consternation of my wife. But when it comes to electricity and electronic circuits, I'm in over my head. So to make a DIY version of the solar backpack, I went to see a couple of old friends who know how to wire and solder. This is Tekserve, a store in Manhattan that repairs Macintosh computers. Mike Edl and Dick Demenus work here. Think of them as the click and clack of DIY.

Mr. DICK DEMENUS (Tekserve): We are very methodical. We're going to engineer this, not just throw it together.

KALISH: Demenus and Edl decide that for the sake of simplicity and to keep costs down, a single solar panel will go on our backpack. It will be attached to a USB cable, which is how you connect iPods and many cell phones to computers. Dick Demenus.

Mr. DEMENUS: The first thing I did is to measure what an iPod typically requires to get charged. So I measured the current - that gave me one parameter - and I know the voltage is five volts. So, now I'm looking for a solar cell that will meet those requirements.

KALISH: You can order just such a solar cell from Jameco, an electronics supplier popular with do-it-yourselfers.

(Soundbite of phone dialing)

KALISH: One of my key objectives here is to make sure that I don't spend more than the $200 for the store-bought version of the solar backpack.

(Soundbite of phone ringing)

YVETTE: Good afternoon. Thank you for calling Jameco. This is Yvette. How can help you?

KALISH: I tell the saleswoman which solar cell I need. It's about the size of a 4x6 photo print.

YVETTE: I do have it in stock. It's priced at 26.15.

KALISH: That's not bad. This is the most expensive part of the project. I also ordered a voltage regulator, which looks like a peppercorn with three short wires coming out of it.

YVETTE: They are 35 cents. Anything else for you?

KALISH: The only other part I need is a capacitor, which sells for less than a dollar each. At this point, Demenus and Edl need to find a way to run the wires from the solar panel inside the backpack, where my iPod or cell phone will be carried while charging. So, with an Exacto knife, they prepare to poke a tiny hole in the backpack. It's a serious business, revealing the creative tension that has made these two do-it-yourselfers professional tinkerers.

Mr. DEMENUS: The good thing about using this thin wire is you could poke a very small hole through your backpack and get this wire through. The wire's like angel hair pasta.

Mr. MIKE EDL (Tekserve): It's more like linguini.

Mr. DEMENUS: Definitely not. The wires together are more like linguini, but each one is like angel hair. It's like…

Mr. EDL: No, no, either spaghettini or spaghetti.

Mr. DEMENUS: I just bought some angel hair pasta yesterday. It looks just like this.

KALISH: Whatever. The point is that now that the wires are inside the backpack, they'll be soldered onto the capacitor and a cable with a female USB plug on the end that will be connected to my iPod. Demenus has encased the solar cell in plastic laminate and surrounded the perimeter with duct tape. He initially resolves to sew through the tape into the backpack, but that proves to be an arduous task.

Mr. DEMENUS: This is going to take forever.

Mr. EDL: This is work.

Mr. DEMENUS: Maybe sewing wasn't the best idea.

Mr. EDL: I agree.

Mr. DEMENUS: Now you agree?

Mr. EDL: Yes, now that I see how difficult it is.

Mr. DEMENUS: This is going to take me hours to sew this.

Mr. EDL: Yeah. Gluing would probably be better.

KALISH: My ears perk up when Mike Edl suggests using glue because I tend to go ape at every opportunity to use Gorilla Glue. I asked Demenus if some form of super glue would be right for the job.

Mr. DEMENUS: No. No. No. No. No. No, no. No, no, no, no, no, no. No.

KALISH: It turns out that super glue hardens to the consistency of glass and would be inappropriate for the soft backpack. Demenus considers using rivets or bolts, but eventually decides to simply staple the solar panel to the backpack.

Mr. DEMENUS: Here we go.

(Soundbite of stapling)

KALISH: The total cost of the solar backpack was about $40. So in this case we are saving some money. But Dick Demenus points out that do-it-yourself projects also provide something that money can't buy.

Mr. DEMENUS: When you do something yourself, there's a joy of accomplishment. And the little things you learn along the way, that's building a knowledge base that you can use for other things. Like, here you have to solder. That's a skill that if you master it you've got it for the rest of your life. And solving these little mechanical problems makes you think about the properties of materials. And it gives you confidence in future if, like, something breaks, hey, maybe I can fix it.

(Soundbite of music)

KALISH: So, now during my forays around Manhattan, I'll be charging my iPod off the grid, at least when the sun is shining. For NPR NEWS, I'm Jon Kalish.

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