Fixes looks at solutions to social problems and why they work.

People often write to Fixes telling us of cool new devices made for the poor: the sOccket soccer ball that stores energy as children kick it; the neoprene LifeWrap that hospitals can use to save women hemorrhaging in childbirth; adjustable eyeglasses.

We love devices — but we don’t like to write about them. It’s cheating. The technology is the easy part of solving problems. There are zillions of cool ideas. Plenty of college students have come up with a great new technology for the poor.

The bigger challenge comes from the questions around any new device: How do you build a market for a technology focused on people with no money? How do you physically get it to where it needs to be? How do poor people acquire it? How can it be adopted on a wide scale? How do you make it last?

If you look at the market for solar lighting in Africa, you’ll be excused for thinking that you’re looking at the mobile phone market some 15 years ago. Both are leapfrog technologies — neither land lines nor the electrical grid is going to reach much of the continent, so let’s just skip that generation of technology and move to the next one. Like cellphones, solar lamps are getting cheaper, smaller, better. Both are life-changing, indispensable. And the market is enormous. Today, about 1.5 million people in Africa use solar lamps. That’s a huge number — but it’s less than 1 percent of the potential market. A fifth of the world’s population lives without electricity. Another large group of people do have access to electricity, but need an alternative because it is too expensive and power outages are daily events.



People without electric light usually rely on kerosene, a terrible alternative. It gives poor light — really, not enough to study by — produces noxious fumes, and is a major hazard for burns and fires. Indoor air pollution kills 2 million people each year and kerosene is a major source. Kerosene itself is also expensive; the very poor typically spend 10 percent of their income or more on kerosene. Its users pay 600 times more per unit of light than people who use electrical-powered incandescent lamps.

The unsolved problem for lighting Africa isn’t designing a great lamp. Great lamps are out there. It’s designing a great business model. Here are three different ways it can work.

~~~

The bottle bulb may be the coolest idea I’ve ever seen.

You take a one-liter plastic soda or water bottle, fill it with a mixture of water and bleach, cap it and seal it. Then cut a bottle-shaped hole in your tin roof and stick the bottle in it, cap up, with part of it above and part below the roof. Seal the hole so the roof doesn’t leak. The water inside the bottle refracts and disperses sunlight. You now have the equivalent of a 50- or 60-watt bulb that will never cost you a dime, burn your toddler or set your house on fire.

The bottle bulb was invented in 2002 by Alfredo Moser, a mechanic in Sao Paulo, Brazil, to light his workshop when his neighborhood was suffering through a long cut in electrical power. Soon, many houses in his neighborhood had the same bottles poking through their roofs as Moser did in his workshop. (Although many people credit M.I.T.’s design lab with inventing the bottle bulb, M.I.T. says it isn’t true.)

Though it was born in Brazil, the bottle bulb’s coming out party is being staged in the Philippines. A tiny Filipino organization, the My Shelter Foundation, has put the bottle bulb in tens of thousands of houses in the last year and is aiming for a million homes this year. The project, called Isang Litrong Liwanag — A Liter of Light — is the perfect grassroots campaign. It starts with community activities — on November 30, for example, 10,000 cyclists delivered bottle bulbs to 17 communities around Metro Manila. But after a few demonstration projects in each community, the only thing that needs to be delivered is the how-to information. This is a technology program where word of mouth and social media really can do most of the work.

This model — make it yourself, for no money, from garbage — solves a lot of problems at once. Affordable, even for the destitute? Easy to distribute, even to remote places? Scalable? Sustainable? All check. (And since it employs old plastic bottles, it’s doubly eco-friendly.) The only challenge is to spread information. That’s not a trivial challenge, but it’s a lot easier than all the others.

The bulb has no way to store energy, so it only works during the day. That’s fine for Moser’s workshop. And it’s more useful for houses than you might think. There are hundreds of millions of families in rural areas or crowded city slums who have no light in the daytime. People who build their own shacks put in tiny windows — really, a hole protected by a makeshift shutter — if they have them at all. So people conduct their lives outside.

But this is obviously far from a complete solution to providing off-the-grid light. Not everyone wants to have a bunch of plastic bottles stuck in their ceiling. And people do, after all, like to see after the sun goes down.

~~~

Higher up on the quality chain are experiments like SociaLite. In 2006, Toby Cumberbatch, a professor of electrical engineering at the Cooper Union in New York, challenged his first-semester students to create a lamp for use in the middle of nowhere, one that cost less than $10 and could go for two days between recharges.

What they came up with was a very simple lamp with a housing made largely of local materials — a hair relaxer tub, an orange drink container and three bicycle spokes. It can be dropped and banged around. It can go 40 hours between charges on the high setting, 400 hours at the low setting.

Courtesy of Toby Cumberbatch

Most revolutionary, it has no charger — instead, the whole community would share a charger. This idea is a variation on a model in use in several countries, the best known being TERI’s Lighting a Billion Lives campaign in India. It has several advantages over simply selling lamp-and-charger sets: the lamp is cheaper. Instead of paying for a charger in intermittent use, people could essentially be paying for a share of a charger in constant use — more efficient. Someone in the community could buy the solar panel (perhaps using microfinance) and start a business charging the lamps and mobile phones — the phone charging might subsidize the lamps. Perhaps most important, customers would not have to pay the full cost up front. They could pay three or four dollars up front and pay the rest in monthly installments, in the form of charging fees.

“We designed it not so much as a product as a service,” said David Berger, one of a half-dozen students in Cumberbatch’s original class who has gone to Ghana every summer to work on turning the prototype into a business. “If something happens— you drop it or something breaks — the people at the base station will give you a spare lantern while yours is being fixed. You’re paying for light, as opposed to a lantern.”

Ghanaians who can afford it can buy solar lanterns in cities and towns. But lamp distributors don’t bother with villages. “The thing seems to be that you pay for it, and if you can’t pay, not my problem,” said Cumberbatch. Berger said that in four summers in rural Ghana, he saw only two lanterns in villages.

The Cooper Union students formed a partnership with Wa Polytechnic, a university in the north of Ghana, the poorest part. Wa students assemble the lanterns, take them out to remote communities, install the solar panel and train local people to run the system. They are then supposed to visit each village once a month.

So far the project is small, in use in only four villages — fewer than 400 lanterns. But the government of Ghana is planning to roll it out in 20 villages around the country.

The SociaLite is designed to fill a crucial niche: a high quality light for use at night by the poorest people in the world. The weak point in the plan might be the creation of a large-scale delivery system. Raj Gupta, deputy chief investment officer at the Acumen Fund (an investor in D. Light), points out that Africa doesn’t have a WalMart or Amazon that provides a standard way to get goods from various manufacturers to buyers. Each company has to invent its own delivery system. SociaLite may need distributors with a greater financial incentive to actually get out to remote villages. (Of course, that will add to the price.)

The project is new and small, and may never end up taking off as a business. But it has a chance — it is an ingeniously designed system for selling a necessary but relatively expensive product to people with no money.

~~~

While these projects are tiny start-ups, the existing solar light business in Africa is enormous. Many companies make solar lights — d.light and Barefoot Power are two of the best-known. These companies are growing exponentially; Barefoot Power reached 1.5 million people by the end of last year, and is on target to reach 5 million this year. Stewart Craine of Barefoot believes the market will serve half of all unelectrified households in the world by 2020.

These commercial solar lamps vary from $10 desk lamps to five-lamp systems that sell for more than $100. The manufacturers say the lamps pay for themselves through savings on kerosene in two to six months. But this is still far too much money for many people.

“We currently don’t target the poorest people in the community, as we sell products for cash, and $25 is still hard to find at one time for many villagers,” Craine wrote in an e-mail.

Barefoot and d.light do try to reach poorer customers, both physically and financially. Joyce DeMucci of Barefoot said that the company often sells in bulk to nongovernmental groups that run camps for internally displaced people. These groups give away the lamps or subsidize their sale. The solar companies also work with local women’s groups or microfinance groups that can provide distribution and financing.

Related More From Fixes Read previous contributions to this series.

Sam Goldman, the co-founder of d.light, said that the major challenge for selling to villagers was supply chain and logistics — “how do we sustainably deliver products and provide after-sales and warranty services?” The company sometimes distributes lamps through businesses already designed to reach the rural poor — sellers of dried frozen fish, for example, or a kind of low-cost roofing, and d.light is starting to work with a multinational company that distributes products in rural Africa. In Guatemala, d.light sells its lamps in mountain villages through the microconsignment system that I wrote about last year.

These programs are small, in part because the potential market for full-price sales is so big. But the price of solar lighting is likely to drop substantially. Gaurav Gupta, who heads the energy and environment practice at the consulting firm Dalberg, makes the point that the demand for portability and energy efficiency is being driven by rich consumers, who want smaller and smaller mobile phones and better solar lights. But those improvements will end up bringing down the cost of solar lighting for the poor. If it gets cheap enough, then there just may be a simple business model that can serve almost everyone — the market.

Join Fixes on Facebook and follow updates on twitter.com/nytimesfixes.



Tina Rosenberg won a Pulitzer Prize for her book “The Haunted Land: Facing Europe’s Ghosts After Communism.” She is a former editorial writer for The Times and now a contributing writer for the paper’s Sunday magazine. Her new book is “Join the Club: How Peer Pressure Can Transform the World.”