AboutDan Fink Expertise Though my experience is mostly in the fields of electricity, magnetism, and physics, I have a broad science background. My career is in the field of alternative power sources -- solar, wind, water and battery power. But any questions about electricity, magnetism, energy conservation, power generation, electric motors, and even general physics are very welcome--especially from kids. They ask the best questions of all! I pride myself in answering science questions accurately, with ideas for SAFE, easy experiments that kids can perform by themselves--and that let them prove the answers to their own satisfaction. I think science should be fun, and available to everyone, regardless of age.
Experience I have volunteered in our local public schools for 5 years. I currently make presentations at our schools about electricity and magnetism, with a focus on solar, wind, water and other alternative power sources. I try to demonstrate at our schools how easy it is to make electricity, with simple devices using spinning magnets and coils of wire--powered by wind, water, bicycles, gerbils...etc. And of course solar panels! I am the webmaster of Otherpower.com, an alternative energy website. I have lived 10 miles from the nearest power pole for 11 years--I make all my own electricity from scratch with sun, wind and water.
Publications Otherpower.com
Wondermagnet.com
Co author of the book "Homebrew Wind Power" ISBN 978-0-9819201-0-8
My articles appear regularly in such magazines as Home Power and Back Home Education/Credentials BA Technical Journalism
Question Hello! I am in 5th grade and have to do a science fair project. I would like to power a caculator with potatoes or oranges. I have found some information but not alot wanted to know if you could help me with where to find research.
Answer Hi Grant. I confess that at age 41 I still make potato batteries. My record is a 12 volt one using 30 potatoes that was able to run a flashlight!
My standard veggie battery tips:
-the more acid in the veggie, the more power you can get, but the shorter time it will last. For example, lemons give you lots of power for a short period of time, while potatoes give you less power for a longer period of time.
-Solid copper is easy to find for one electrode; just use plain old copper house wire (romex) with the insulation removed. For the other electrode, remember that galvanized nails (the usual method) are only COATED with Zinc. It's eaten away quickly by the electrochemical reaction. Instead, go to the hobby store and buy solid Zinc strips (anyone that sells chemistry sets should have them).
-You MUST have a multimeter or volt meter to try and run a calculator, LED lights, LCD clock, etc. You can buy a decent multimeter for under $15.
- See what voltage your calculator uses. The batteries are likely in series, so see what each battery is rated in volts (printed on it, or measure it with your voltmeter) -- add those numbers together, that's your operating voltage.
- now start making veggie batteries. Connect them together in series (+ to - to + to - to + to - and so on) until the voltage measured at the far ends of the string of batteries equals what the calculator needs. Your voltage should increase with each veggie battery you add in series; if it does not, you have a bad connection or rotten potato somewhere in there.
- that should do it! If your calculator still does not run, try a couple more veggie batteries in series. If it STILL doesn't run, it likely needs more amperage than your batteries can provide. Try another calculator, digital clock, etc. that uses less power.
-See why the multimeter is essential? Otherwise you'd have no idea what voltage your batteries were making, and just guessing at how many you needed. Keep the meter, you'll use it all through middle school and high school for science projects.
