A few years ago I wrote disparagingly about Bill Gate’s Reinvent the toilet challenge, after it declared a hydrogen fuel cell toilet the best innovation to bring toilets to the 2.4 billion people without one. I haven’t come back to the competition since, but there have been further rounds and the Gates’ have invested millions in alternative toilets of one kind or another since. I thought I’d better check in again, and there are now some really good ideas on the list. I was also pleased to see that there are a variety of local challenges and trials in various locations, as there isn’t going to be a one size fits all solution.
2.4 billion people without a toilet is a huge challenge, especially since we can’t roll out flushing toilets everywhere. There isn’t enough water, and the sewers and treatment plants would be prohibitively expensive. If climate change brings more drought, those lucky enough to have a flushing toilet today might start to wonder why such a wasteful technology became so commonplace.
I’ve featured a bunch of waterless toilets before, and there are quite a few in the Gates programme that I could mention. I’m going to go with this one because it’s from Cranfield University, which is practically local. It’s called the Nano Membrane Toilet, and here’s how it works:
I have a few questions about this still. The challenge was to build something that doesn’t need a water, sewage or electrical connection. Is it powered by the poo? Because I see an incineration process in there, and that must be energy intensive. I don’t suppose paper can go through the archimedes screw, and if it got jammed it would be a nightmare to unblock.
On the plus side, I love the simplicity of closing the lid, and all those cogs flip round underneath to clean it. If it does work self-contained, then you could deliver it and stick it in an appropriate room like a piece of furniture – no plumbing or installation required. If I ever live the middle class dream and install a downstairs toilet in my house, I’d like one of these.