Bill Gates has a lot to say about toilets, so much in fact that his foundation has a “reinvent the toilet” initiative.

If we can develop safe, affordable ways to get rid of human waste, we can prevent many of those deaths and help more children grow up healthy.

Western toilets aren’t the answer, because they require a massive infrastructure of sewer lines and treatment plants that just isn’t feasible in many poor countries. So a few years ago our foundation put out a call for new solution.

One idea is to reinvent the toilet, which I’ve written about before.

In developed countries, what we do is build energy- and chemical-intensive factories to purify surface or groundwater into clean drinkable water, use more energy to transport it a short distance in pipes, defecate in it, transport it a short distance again (usually by gravity but sometimes with more energy-intensive pumping), then build another energy- and chemical-intensive factory to remove most of the fecal matter from it, before we dump it back into a river and the process begins again with the next town downstream. This system was not designed all at once, but evolved piece by piece over the course of a hundred years or so. If we were starting from scratch, it is highly likely we could come up with a better system. We don’t try because of all the money and effort we have sunk into the existing system. If somebody develops a truly better way of dealing with waste, turning it into useful energy, water, and fertilizer, without violating powerful social taboos about how to deal with waste, that will be a game changer. The concept is that developing countries using such a technology could “leapfrog” developed countries and never have to build the centralized infrastructure, much as they have with cell phones.