This has been reposted from the Mercy Corps blog.

On my first day in Zimbabwe, I went to visit some farm families in the town of Murejwa. People are poor there, and Mercy Corps is working with them to find ways to boost their incomes.

In this video, I'm with Fred and Beauty Jokonya, who live and farm on a half-acre on the outskirts of town. The star of this show, however, is a piece of basic technology: the treadle pump. As you'll see, this pump has made the farm and its owners a lot more productive.

I mention in the video that Fred and Beauty are looking after many of their grandchildren. What I don't mention in the video but want to note here is that the kids are AIDS orphans. In recent years, about 20 percent of Zimbabwe's adults have been struggling with HIV/AIDS and as a result there is a whole generation of kids being raised by their grandparents.

The use of sawdust stoves is making lives easier for small-scale farmers throughout the timber regions of Tanzania and Zambia, says an article in The Times of Zambia. These special stoves are a cheap, easy to use, sustainable alternative to using charcoal and are in many ways more effective.

According to the article, the sawdust stoves work well in this region because they run without electricity. Given that less than 20 percent of the population has access to electricity, it is necessary to have a non-electric source of energy like charcoal or sawdust.

Where sawdust stoves take a strong advantage over charcoal, however, is in its health and environmental impacts. A recent report on the health and environmental effects of cooking stoves describes how the charcoal trade is accelerating deforestation in the region, and the health problems caused by charcoal stoves, which includes, respiratory issues, eye irritation and carbon monoxide poisoning.

In contrast, the sawdust being used for these stoves is timber waste, so it provides a free and uniquely sustainable form of energy that would remain unused otherwise. According to the video below, the stove pays for itself in saved charcoal costs within two to four months. The stoves themselves are cheap and easy to make, which makes them accessible to those with very low incomes. In the video, cafe owner Roze Mgina explains the benefits of her sawdust stove:

I cook everything, rice, beans, donuts, using just one stove. If you put a bit of firewood in the vent, it gets hotter and cooks things quicker. When I use charcoal it gives me a headache if I stay a long time in the kitchen. With this one I don’t get headaches anymore because it doesn’t produce any smoke.

The Kisangani Smith Group, based out of Tanzania, won an Ashden Award for Sustainable Energy in 2008 for training blacksmiths to make and sell these sawdust stoves. The group has sold more than 3,500 stoves in Tanzania and elsewhere, and continues to provide jobs and training to aspiring blacksmiths.

Have you heard of "appropriate technology?" It's a movement that helps the world’s poorest people with affordable, simple and practical inventions that address every day problems.

Some examples include:

• The Q-Drum, a circular drum that allows women and children to transport water by pulling a rope attached to the jug as it rolls on the ground, instead of carrying it on their heads.
• The Lifestraw, a portable, filtered drinking straw that allows water to be safely sipped from rivers, lakes and ponds.
• The Solar Home Lighting System, which allows children to study at night using solar-powered screens instead of electricity.

"We need to see the poor as customers rather than charity recipients," says Paul Polak, one of the notables in the appropriate technology movement. "We need a revolution in how multinationals design, price and market their products. There is a huge virgin market out there!"

Explore photos and videos of more inventions at Design for the Other 90%, the website for an exhibit currently touring U.S. museums.