Lisa Margonelli reports on efforts to turn soil into energy:
In sub-Saharan Africa 500 million people have no access to electricity, but nearly a quarter of them have cellphones. Charging these phones is tough: some people walk miles to commercial charging stands that cost 50 cents or a dollar to top up the battery, a significant part of a family’s income. Solar panels for the purpose can cost $20 or more and they have a local reputation for being hard to repair.
What these people need is a very cheap, very simple, very tiny trickle charger to keep their phones going. And that is how Aviva Presser Aiden, a Ph.D. engineer who is now a student at Harvard Medical School, became interested in generating electricity from dirt.
They've had some success:
Now their cells are producing 75 to 400 microwatts of power— enough to charge a small cell phone in about a week. (This may sound impractical but if the phone is plugged in most of the time it will rarely require a full charge.)
The Dish 