In many places, the simplest needs – clean water, efficient sanitation, sterile medical equipment – can be the most difficult to meet. Take a look at three start-ups that have embraced practical designs that cater to people without reliable access to electricity and other infrastructure, offering smart yet low-tech solutions to high-stakes problems.

Sanergy 

Based in Nairobi, Kenya, Sanergy is tackling sanitation issues in developing nations with a multistep approach: building a network of clean toilets, finding local entrepreneurs to manage them, collecting the waste, and converting it to fertilizer that can then be sold.

“In the slums, it’s common for people to pay 3 to 5 shillings [about 3 to 5 cents, in U.S. dollars] per toilet use – even for pit latrines,” says David Auerbach, a Sanergy cofounder who graduated from the Sloan School of Management at the Massachusetts Institute of Technology. The entrepreneurs who operate Sanergy’s toilets (under the brand name Fresh Life) will continue to charge a fee, but toilet users will enjoy a more hygienic experience. Unlike pit latrines, Fresh Life toilets will be emptied daily, and offer toilet paper and hand-washing facilities.

Cleanliness wasn’t the only requirement for the Fresh Life toilet. The design team knew it had to be inexpensive and compact. (“Space comes at a premium in a slum,” Auerbach notes.) In 2010, Sanergy installed two prototype toilets, which cost less than $200 each to construct, in Nairobi’s Mukuru slum. The company has trained people to work as Fresh Life franchisees, and Auerbach expected that by the start of this year, it would be building 60 toilets in Nairobi to serve 5,000 residents.

Sanergy received the grand prize in MIT’s $100K Business Plan Competition last year, along with the $5,000 Audience Choice Award. It also won the $12,500 grand prize in the University of Washington’s Global Social Entrepreneurship Competition as well as that competition’s prize for social impact, worth $1,000. To be eligible for that award, Sanergy’s founders met with the Rotary clubs of Nairobi Parklands and Cambridge, Mass., USA, which led to an unexpected benefit: Anju Paunrana, a member of the Nairobi Parklands club, works in her family’s mining business – which has a cement division. “We’ve been able to buy cement at wholesale prices, even though we’re quite a small operation,” Auerbach says.

Though he’s happy about the awards, Auerbach knows that the people who use the Fresh Life toilets will decide whether Sanergy succeeds. So the company is also working on a better way to clean out pit latrines, which can be up to 13 feet deep; waste is often scooped out with shovels and buckets, an unpleasant task. Sanergy is testing a bicycle-powered pump that would suck the waste out of the latrine. “Our goal is to take people who operate pit latrines and convert them into Sanergy toilet operators,” Auerbach says. “But in the meantime, we need to show them the value of what we’re doing. And part of that is if you have a cleaner latrine, you’ll have more customers.”

Solarclave

In rural areas, sterilizing medical instruments can be difficult, because an autoclave requires a reliable source of electricity. “They’re so energy intensive that it’s not practical to run them on a generator,” says Anna Young, research and development officer for International Laboratories of Innovations in International Health at MIT.

Two years ago, Young joined forces with electrical engineer Ted Liao at MIT to design Solarclave, a solar-powered autoclave. It’s essentially a modified 4-liter pressure cooker insulated with fiberglass and covered by a bucket. Dozens of small mirrors angle toward the base of the vessel, which is painted black to help it absorb heat. After 30 to 60 minutes, the Solarclave reaches 121 degrees Celsius, the sterilization temperature recommended by the U.S. Centers for Disease Control and Prevention. From there, the Solarclave can sterilize instruments in 20 minutes.

If a mirror breaks, health-clinic workers can make a replacement by covering a piece of glass with Mylar from the inside of chip bags. It won’t be as efficient as a mirror, but it will work, Young says. The ability to carry out their own repairs, however MacGyver-like, makes workers more comfortable with Solarclave, she says, which is essential in places where mechanical problems often doom high-tech devices: “One screw falls off, and everyone is afraid to touch it. It becomes part of an equipment graveyard.”

PotaVida

The sun can also help purify the most basic necessity: water. All you need for solar water disinfection, known as SODIS, is a transparent bottle made of PET plastic (the material used for most disposable beverage containers). Fill the bottle with water, leave it in direct sunlight for at least six hours, and the one-two punch of UVA rays and heat will destroy harmful bacteria. Studies show that when used to purify drinking water, this process can significantly reduce the occurrence of diarrhea. That will have a profound effect: Diarrhea results in more than two million deaths each year.

Solar disinfection is not new – researchers discovered its effectiveness about 30 years ago. But if it’s so easy, why isn’t it more widespread? “The problem is, it’s so simple, people don’t think it’s going to work,” says Charlie Matlack, a doctoral student in electrical engineering at the University of Washington. Matlack is also president of PotaVida, a start-up that aims to increase the use of this process.

He designed an inexpensive device, the PotaVida, that attaches to bottles. The small solar-powered circuit measures how much light comes through the bottle, and has an LED indicator to monitor the disinfection process. “It’s like using the guts that you would find in a solar-powered calculator,” he says.

Matlack and his team are still refining PotaVida’s design so people will know how to – and want to – use the device. A team member brought a mechanical mock-up to Nicaragua last summer and found that local residents had questions of their own. “People want to know, ‘Does it make me look rich, do people want to steal it, does it fit in culturally?’” Matlack says.

But he notes: “It’s critical to not get too focused on a technological feature that you think will solve the problem.”