DIY Solar Panels

September 8, 2009 by James Munns 74 Comments

solar

Reader [unangst] pointed out to us an article in the U.K.’s Daily Mail, where a teenager from Nepal had managed to create a 9v, 18W solar panel using human hair rather than the usual semiconductors (usually crystalline-silicon). The complex silicon in solar panels are what keep the prices out of reach of developing nations, and while there are a number of new technologies that are helping bring down the cost, [Karki] managed to make his solar panel for only £23 (roughly $38). He also claims that when mass produced the price could drop substantially down to under $10 a panel, which would shatter the $1/watt sweet spot.

The melanin in hair acts as an organic-semiconductor, and while the hair does not have the longevity that silicon panels have (months rather than years), these panels can be made cheaply and serviced with little to no complex knowledge. Using melanin as an organic semiconductor seems to be a newer idea, because information seems hard to come by, but we managed to find a research paper from 2007 that explored the energy absorption attributes of melanin, as well as some good background info for the science types.

Research Paper (Warning: PDF)

So, Hack a Day readers, which one of you is going to make your home-brew solar panels first? Let us know when you do.

Thanks [unangst].

[digg=http://digg.com/environment/Teenager_Makes_DIY_Solar_Panels_from_Hair_Hack_a_Day]

I-Swarm Robot Update

August 31, 2009 by Mike Szczys 9 Comments

I-Swarm_Micro_Robot_On_Thumb

Back in October we reported on the I-Swarm robotics project. [Travis] sent us some more information. These tiny robots are programmed optically and are able to respond to programming commands via an infrared signal. Locomotion is facilitated with piezoelectric actuators and the power to the units provided through a solar cell. It is not clear that this project is still ongoing as the I-Swarm web page lists a project termination date of 6/31/2008. That being said, the video embedded after the break was posted two days ago showing swarm movement and detailing the programming, testing, and hardware specifics. Continue reading “I-Swarm Robot Update” →

Energy Efficient Fridge Hack

August 27, 2009 by James Munns 39 Comments

Green_Freezer

We’ve already covered a pipe bomb mini-fridge this week, but inventor [Tom Chalko] provides us with today’s fridge hack. He noticed that chest-style (laying down, see above) freezers were more energy efficient when compared to normal stand up refrigerators at the same size, despite the colder temperatures involved. This is largely due to the fact that these chest-style freezers keep cold air in like water in a bowl, even if the lid is open. He has written a very thorough report on his findings (pdf), as well as a detailed walk through of the manageable task of converting a chest-style freezer into a chest-style fridge. In the end, his fridge only used 103 Wh of electricity on the first day to reach and maintain between 4° and 7° C (39° to 45° F), and he noted that 30% of that was just getting it up to temperature. After that, the fridge only turned on for roughly 90 seconds an hour, making it a very quiet fridge as well.

Strobit Wireless Widget Project

July 11, 2009 by Caleb Kraft 10 Comments

Strobit looks like it could be a project to keep an eye on. The entire project is open source, including the hardware. The aim is to build a low cost, low power, wireless enable arduino powered widget. This seems like it could really cut down on the development time of many projects we’ve seen here. Development is still ongoing but it looks like they’ve already implemented some mesh networking similar to the zigbee systems.

[via hackaday flickr pool]

Radish – Eco Friendly Google Calendar

April 17, 2009 by Caleb Kraft 26 Comments

[youtube=http://www.youtube.com/watch?v=VyHaImmmkGs]

[Aaron] a google employee came up with an idea that would be good for the environment, as well as fun. The Radish is a solar powered display, updated from a google calendar, with extremely low power consumption. They are building this to be an indicator of the conference room schedule. When we first read this, we wondered just how much greener it could possibly be than printing a few sheets of paper. Then we read that they were going through six reams per day. wow. The Radish gets its power through a solar panel, and preserves it through some creative power saving modes and the fact that it has an LCD that only requires power to update. Would this be a good place for some E paper? Data is transferred using IEEE 802.15.4, which is slow, but also more efficient in terms of power than normal WiFi. The system is so efficient, it can run for 3-4 days in low light conditions after a charge . Another cool fact is that [Aaron] got to design and build this on company time. Google allows people to spend 20% of their time on innovative new projects of their choice.

correction: the LCD goes into an extremely low power “sleep mode” when not being updated, and retains the last image loaded.

Solar Cells From Donuts And Tea

March 19, 2009 by Caleb Kraft 41 Comments

[youtube=http://www.youtube.com/watch?v=bVwzJEhMmD8]

It sounds unbelievable, but it is true. You can harvest most of what you need for a simple solar cell from powdered donuts and tea. Powdered donuts have nanoparticles of titanium dioxide which is a “high band gap semi conductor”. This means that it can be used to make solar cells. The tea is simply used to dye the material so it can pick up the visible spectrum. The process is a bit too involved to be something you would just toss together in the field, but it’s cute nonetheless.

Solar Batteries

February 16, 2009 by Eliot 51 Comments

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[Knut Karlsen] put together a prototype set of solar rechargeable batteries. He always seemed to have batteries laying around on his worktable and figured they might as well be charging. The flexible solar cells were given to him by researchers at the IFE and are rated at 1.8V. He used superglue to secure them to the C cells. A silver conductive pen plus flat wires from a Canon lens connect the solar cells to the battery terminals. The batteries just trickle charge for now, but he’s going to try to build cells with built in charge controllers in the future.