Overview of booths in the World Bank Development Marketplace exhibition hall

Teams of inventors and entrepreneurs from around the world were in Washington recently to showcase innovative solutions to problems in the fields of water, sanitation and energy.

Judges at the World Bank's annual Development Marketplace narrowed the field from 2500 applicants down to 118 finalists from 55 countries. At stake were grants for up to $200,000 to jump-start their projects.

The spacious lobby of World Bank headquarters is crowded with booths where exhibitors are showing off their projects. Some are expensive-looking, professional jobs. Others show more enthusiasm than fancy graphics. But all feature ideas that, in some way, promise to change people's lives.

Carl Erikson exhibits ISAAC Solar Icemaker with Rural Milk Collection Center representatives from Kenya

You've probably heard of solar heating and solar cooking. Carl Erickson wants to bring solar ice-making to Kenya. At present, many small dairy farmers lose much potential income to milk that has spoiled. To prevent that, they can boil the milk, but that robs it of taste and nutrients. Erickson's technology is based on ammonia absorption, a century-old refrigeration technique. "And if they had ice, they'll be able to chill these products so that they can have more time to market it to the urban areas, so that they'll be able to sell it," Erickson says.

A few steps away, another technology is on display, this one perhaps a little more familiar to many of you.

Kristine Pearson of the Freeplay Foundation

If you normally listen to a Freeplay radio - the one that you crank up - you have listened to a cousin of this device, called Weza. It's a small box that sits on the floor with a pedal that you pump with your foot.

"It's a portable energy source that offers reliable, dependable power anytime, anywhere," says Kristine Pearson of the Freeplay Foundation. "It charges a wide range of communication and other low-energy devices such as cell phones, LED lights. It can even jump-start a motor car and pump a tire."

Pearson says the foot-powered generator can also be used to power medical devices, which could improve health care in rural areas. The Foundation will train and support 50 Weza "pioneers" in Rwanda, who will set up micro-businesses, essentially selling power to their neighbors.

Kyrghyz innovator Nurian Moldosherip with Habitat for Humanity's Natalie Grant

Both the Weza generator and the solar powered icemaker were among the winners at this year's World Bank Development Marketplace, as was a proposal by Habitat for Humanity for affordable housing in Kyrgyzstan. They want to marry efficient, under-floor electric heating with a traditional but now abandoned construction technique using cane reeds as a sustainable source of insulation. "With this technology the cost of the house is 40 percent cheaper just to build, and then the cost of the energy to heat the home is 75 percent cheaper," says Habitat for Humanity's Natalie Grant, who adds that some Kyrgyz families spend up to half their income on heating.

In China, the plan is to use shellfish to purify polluted waters. The challenge, explains David Aldridge of Cambridge Environmental Consultants, is persuading local residents to leave the mussels in the water. "One of our problems is that the Chinese, like many Americans, like to eat mussels," he says. "So what we need to do is to make the Chinese value our mussels more as alive than mussels on a dinner plate."

David Aldridge with the Chinese mussel proposal display

His solution is to seed the mussels so they will produce pearls, creating a new industry that also cleans up the water. "So we have a commercial product that the Chinese communities can sell and therefore they propagate the mussels for us," Aldridge says. "They get money; we get clean water, and everybody wins."

The Chinese partner in that proposal, the Kunming Institute of Zoology, couldn't be in Washington as their representative was not issued a visa.

Thirty of the projects won World Bank funding, including the ones we've mentioned so far. But even among the others, there was excitement and innovation.

In Haiti, there was a proposal to install wind-powered water pumps in a rural village of 5,000 residents, with the windmills and water tanks on hinged poles that can be easily lowered in the event of a hurricane.

Johannes Siregar invented floating toilets for Indonesia's coastal area houses

There were water projects in Uzbekistan and the Gaza Strip that remove salt from brackish water using inexpensive, solar-powered devices made from local materials.

Or my personal favorite: engineering student Johannes Siregar and his floating toilets, which he says have the potential "to solve a big problem in [his] country [Indonesia]." Many Indonesians in coastal areas live on houses built right on top of the water, and they don't have proper toilet facilities, so untreated human waste is dumped right into the water. The floating toilets would include septic tanks and filtration material, all from locally-available sources. Why floating? Simply because there is no land available to build on.

TV reporter interviews participant at the World Bank Development Marketplace in Washington, DC

World Bank President Paul Wolfowitz told the competitors that even those who didn't win funding had gained a lot. "I think… that everyone who's here is a winner. You were outstanding just to get here," Wolfowitz said. "I hope, even if you don't leave here with an award, you'll leave here with a new network of contacts, with a new wealth of knowledge and ideas. And hopefully, the interactions that have taken place here between participants will generate even more innovative ideas."