The simple invention that could save the world

Flushed: This toilet, designed by Cranfield University, also works to “block odours”.

Is focus the key to success? Yesterday was World Toilet Day — and it was no laughing matter. Bill Gates has spent seven years and £155 million reinventing loos. They may save thousands of lives.

Earlier this month, Microsoft founder Bill Gates stood in front of a crowd at a conference in China holding a jar of human faeces. “I have to say, a decade ago I never imagined that I’d know so much about poop,” he joked. But he does — he knows so much that his wife, Melinda, has to tell him to stop talking about it at the dinner table.

Yesterday, on World Toilet Day, he reminded everyone why: because lavatories save lives.

According to the World Health Organisation, 4.5 billion people (around six in 10 of the world’s population) do not have access to “safely managed sanitation”.

In wealthy countries, most people take clean toilets for granted. In developing countries, rural areas and fast-growing megacities often do not have sewage systems or treatment plants. According to Gates, it would cost “many billions of dollars” to go back and build sewers in just one Indian city.

This does not just make slums dirty and unpleasant. It also spreads diseases like cholera and typhoid. Diarrhoea alone kills almost 500,000 children under five each year, according to the UN.

So in 2011, Gates launched the “Reinvent the Toilet Challenge”, calling for safe, clean toilets that did not rely on sewers. In the seven years since, his foundation has donated more than £155 million to companies and universities that are researching solutions.

Twenty new “reinvented toilets” were unveiled at the conference in China. Gates described them as “the most significant advances in sanitation in nearly 200 years.”

Most are able to turn urine into clean drinking water, and can dry and burn faeces to produce electricity. The self-contained systems will also help to save water in areas where it is scarce.

There are still a few problems ahead. Firstly, scale: can the products be made cheap enough for the poor communities that need them most? Then there are the taboos around toilets; many poor governments simply do not want to invest in cleaning up poop.

Bill Gates has always said that “focus” is the secret to success, whether you are working on toilets or computers. Is he right?

On a roll

Yes, say some. The author Malcolm Gladwell argues that it takes 10,000 hours to become an expert at something. That means few distractions and years of practice and attention. If you want to save the world, choose one small but important problem and obsess over it until you have a solution.

This is bad advice, argue others. The best ideas come from the people who can see the whole picture — who have a broad range of knowledge and can make connections between things more easily. For proof, look no further than Leonardo da Vinci: an artist, scientist, inventor, writer and architect.

You Decide

  1. Should all homes have waterless toilets?
  2. Would you rather be the best at one thing, or quite good at lots of things?


  1. List five other simple problems that could be solved to help save the world. (Hint: “climate change” is not simple!)
  2. Have a go at designing your own waterless toilet! Draw a diagram which explains how it works.

Some People Say...

“If your culture doesn’t like geeks, you are in real trouble.”

Bill Gates

What do you think?

Q & A

What do we know?
A WaterAid report for World Toilet Day found that one in five primary schools and one in eight secondary schools do not have any toilets. Around 4.5 billion people do not have clean and safe sanitation, while 2.5 billion do not have toilets. Around 800,000 are forced to defecate out in the open. This can cause environmental as well as health problems.
What do we not know?
Whether Bill Gates can actually solve the problem. Part of the challenge was to create a toilet that costs less than five cents per use, but this has not yet been achieved. Even if it was, it is not known whether the poorest communities will decide it is worth the money. On the flip side, the environmental benefits may mean that the toilets eventually become popular in wealthy countries too.

Word Watch

Bill Gates
The co-founder of Microsoft is the second richest person in the world (after Jeff Bezos). He has been at the top of the list, or near it, since 1995. He has given at least £39 billion to charity.
500,000 children
According to data from 2016. This accounts for around 8% of deaths among children under five worldwide.
The Bill and Melinda Gates Foundation was created in 2000. It focuses on five key areas: finding solutions to health problems; developing the world’s poorest communities; economic growth; US education; and promoting “policies that will help advance our work.”
Save water
In the US, toilets account for around 30% of a household’s water consumption. This is not sustainable in many poor countries. Instead, many of the reinvented toilets help to produce water by cleansing urine. (It could even be used for drinking!)
10,000 hours
Gladwell wrote about this in the book Outliers, but the figure actually comes from a 1993 study about learning musical instruments. Whether it is true is up for debate; see Become An Expert for more.