Energy source found in tap water... but it's all a matter of scale
Life is like a sewer - you get out of it what you put into it
- Tom Lehrer
Are the column inches devoted to headlines in conventional publications always so misleading?
Scientists find new way to make electricity, Cdn researchers find new source of electricity, Electricity Discovery Pumps Up The Power, Energy source found in tap water, Response gives profs a charge, Lightbulb moment leads to clean energy source Can water run your mobile?
I'm not going to list all the publications involved (if you want, you can hit this google link
for more headlines on this topic), but the reprints all stem from an original article in the Journal of Micromechanics and Engineering
about generating electricity "electrokinetically" from pushing water through microtubes.
Most of the glassy eye'd, enthusiastic transcriptions of what must have been a carefully worded press release by a PR agency manage to miss what Nature magazine nailed - that a conventional water driven turbine was far more efficient than the current electrokinetic process...
. The new process is currently less than 1% efficient where a hydroelectric turbine can be 80-95% efficient - so we aren't going to see any change in how dams are built any time soon. (more about that in a minute, after I get done ranting)
No... instead almost universally, the articles mention that in the experiment, water was Squeezed through a syringe
and powered a lightbulb
a VERY SMALL light bulb. A very, very, very, very small lightbulb.
The howler headline?
Energy source found in tap water
In a world where tap water is subsidized heavily (as in supplied free), sure. But it would be much more efficient to power your house with small turbines under each tap and garden hose!
The second howler in this headline? Electrokinetics is not an "energy source", OK? At best, it's an "Energy storage mechanism". A battery. You can quibble about where energy actually comes from but in the case of this experiment, it came from a syringe. (Again... nature mag got it right.)
The three laws of thermodynamics (paraphrased)
You can't win
You can't break even
You can't even get out of the game
Water that gets pumped uphill to your tap can't possibly generate more energy on the way down than on the way up.
Another howler headline: "Can water run your mobile?"
Fuel cells may be appearing in consumer devices in the next couple years. A fuel cell generates water as a byproduct of the energy retrieval process (it's still a battery, you have to pump energy in to get energy out). It's highly unlikely that highly pressurized water will be used to power your mobile - but highly pressurized hydrogen gas is a distinct possibility.
So, anyway, in short, electrokinetic electricity generation is a new idea, but it is, at best, a far more inefficient means of storing and retrieving electricity, especially in bulk, than most other known means. Sensationalism over science does everyone a disservice. Years from now 1000s of people will think that electricity from water is a suppressed technology, just like cold fusion
Now... having roundly debunked some of the more absurd statements made about this discovery, I'd like to place emphasis on the original context by which the scientists announced it. I was going to talk about really tiny machines - and about teflon, and a few other things - but I'm runninglate, and I'd rather you just read Dr. Richard Feynman's 1959 speech on There's plenty of Room at the bottom
The world functions differently at the cellular or molecular scale. Electrokinetic energy might actually make sense as a means to power devices much smaller than your mobile. How small? Chips the size of what Dust, Inc.
is working on. Or smaller.
More later. Maybe.