Friday, May 11, 2007

Solar water heater plans from Mother Earth News

When we lived in Rarotonga for a short time in 2003, everybody used solar water heaters. They were mounted on the roof. Even though Rarotonga is a tropical island, it's cloudy and rainy a lot so we took many cool showers.

I think I solar water heater would work well in Los Angeles. John Park, a contributor to MAKE just sent me a link to an article from a 1984 issue of Mother Earth News about making a solar powered water heater. Here's the first paragraph:

For the do-it-yourselfer searching for an inexpensive, easy-to-build solar water-heating system, the integral passive solar water heater (IPSWH, pronounced ipswah ) is a dream come true. All you need to get going on this down-to-earth water warmer is a discarded electric water heater tank rescued from the local dump, a homemade plywood box to house it in, a can of flat black paint, a sheet or two of used window glass or clear plastic, a few common plumbing fittings and some pipe and insulation. Combine all that with some spare hours of satisfying sawing, hammering and wrench-turning, and you'll have an ongoing supply of hot water provided virtually free from that friendly furnace in the sky.

It sure is ugly, but maybe it doesn't look as bad when it's up on the roof.


Wednesday, May 9, 2007

Making a solar powered gadget recharger

I'll be the first to admit that I don't know what I'm doing here, and I'm probably going to fry the circuitry of hundreds of dollars worth of gadgets before I learn anything. But I think it'll be worth it. I bought a couple of these solar-powered AA battery chargers when my family and I moved to Rarotonga in 2003. They worked quite well.

I recently came across the chargers in storage and decided to see if I could use it to recharge my iPod, digital camera, and cell phone. It figured it would come in handy as a device charger when I cut the power to my guest house.

All of these can be powered using USB, or though an appropriate Zip-linq USB cable. I had a spare female USB extension cord laying around, so I clipped off the male end, stripped the wires, and soldered the red wire to the positive side of the solar charger and the black wire to ground (I found out what the different colored wires were for here).

It's been very hot and sunny here in Los Angeles this week, so it was a good time to test this device out. I plugged my iPod Nano into it, and for a brief instant, the recharge icon flashed, but then it went dark. I do know that power is being transmitted through the wires, though, because when I plugged a USB-powered LED lamp into the charger, it lit right up.

My next step is to buy some good rechargeable batteries (the ones I have are spent) and charge them with the charger. Then, I'll see if the stored charge in the AA's will charge the iPod. I'm not sure if they will, because the batteries are connected in parallel, not series.

Also, I wonder about the potential for damage to my devices. I don't mind sacrificing some of my stuff in the name of learning, but there's no reason to kill my iPod if it can be easily avoided. I'm thinking of incorporating Limor Fried's Minty Boost circuitry into my charger to protect my devices.

If you have any ideas or advice, I'm all ears.

Tuesday, May 8, 2007

Solar powered lamp

This portable LED lamp looks interesting. I've asked for an evaluation unit. You can set the solar panel outside, and then bring it indoors and plug it into the lamp at night. Link

Unplugging my guest house

Living in Southern California, we're blessed with sunny skies for much of the year. I am curious to learn about new technologies that I can use to make useful energy from the sunlight that hits my property. To do this, I'm going to convert my guesthouse (a separate, 400 square foot house with bedroom, office, kitchen, and bathroom with shower) into a solar- and human-powered test lab.

The purpose of this blog is to document the process.