Turning toilets green

The amount of water flushed down our toilets is considerable – in fact, it’s the second biggest use of water in the home behind showering.

There must be a way to harness all this moving water, right? Well actually, the technology does seem to be there to turn toilets into a kind of home hydropower system.

Will toilet tech bring electricity-generating flushes?

Back in 2014, research was published on a device using a transducer to convert the motion of water into electrical energy – with its suggested application in ‘home water flushing’ particularly capturing the imagination.

So, will we soon be charging up our smartphones or even doing a wash on the electricity generated by the day’s toilet flushes? Not quite. At that point, proof of concept was based on the ability of water movement to light an LED, and the researchers did point out that this was technology in its infancy, with potential gains dependent on factors like flow speed and the structure of the device. Unfortunately, infancy hasn’t turned to technological maturity yet, as there clearly remain a distinct lack of power outlets on our cisterns.

It’s not the only flush power technology that has been mooted, though. There’s also the Benkatina turbine, a hydroelectric turbine made to fit inside pipes and deals with variable water flow. Sounds promising in pursuit of powering up those WCs, but unfortunately here again, there hasn’t been much public progress with the technology since five or so years ago.

Super sewage offers other green options

We’re yet to see early progress in this area turn to toilet flush hydropower becoming the norm – but there are plenty of examples where the potential of human waste as an energy source is being tapped. The authorities of Portland, Oregon are selling sewage effluent as a viable fuel, while in Colorado, eight million tonnes of human waste is being converted into biomethane to be used in vehicles such as buses.

Please click here for the full Energy Saving Trust article.