Getting power to rural African villages is a goal of dozens of activists, designers and organizations. For example, Light Up Malawi is working to get the entire country connected to renewable energy; EGG Energy has created a battery swapping program so villagers are never more than a bike ride away from a full charge; and sOccket is a concept for an energy-generating soccer ball that can be played with all day, then plugged in to light up a room at night. Getting power to those without is a big quality-of-life booster, and that's why even retired professor Robert Lange is adding his effort to the cause.

Boston.com reports that nearly 200 solar panels have been installed on roofs in the past two years in the two villages on Tumbatu, a tiny islet a mile off the coast of the main Zanzibar island in Tanzania, thanks to Lange and a small nonprofit he runs from his apartment in Cambridge, Massachusetts.

His nonprofit trades villagers their wood stove for solar panels. For every one solar panel given to the community, the villagers have to install four new fuel-efficient cooking stoves. While it sounds like a trade-off, it really is a double win for the villagers. Smoke and emissions from wood burning stoves are rough on the environment and the lungs of the people living near them. The villagers are therefore getting a healthier way to make their meals, and a new source of renewable energy for charging small devices like radios, cell phones and lamps. It's a great trade!

"We're trying to set up an informal carbon credit market,'' Lange says. "We're saying four stoves is worth about $130 in reduced emissions over eight or 10 years, and for 130 bucks we can buy and import a household-scale solar energy system, to give you lights, charge your cellphone, and run a radio.''

Lange's friend, Robert van Buskirk, another Harvard-trained physicist, pioneered the solar panels-for-stoves program in Eritrea in the Horn of Africa. Lange is continuing it, hoping to expand to Masai villages in northern Tanzania and southern Kenya - areas which have the worst indoor pollution he's ever seen, he states. Hopefully not only Lange's program can expand and be successful, but more people will catch on to the clever idea. It works so well, the professors state, because scientific expertise is offered without imposing ideas or making people dependent. Rather, quite the opposite - the program makes any willing villagers the owners of their own off-grid technology.