In Part 1 of this post, I introduced you to (probably re-introduced you) to Dr. Emmett Brown, that slightly wacky scientist of Back To The Future fame. I referenced several articles, and in this one I’ll continue with those and others, like this one from Clean Technica, which opens like this:
"Researchers at MIT, led by professors Franz-Josef Ulm, Admir Masic, and Yang-Shao Horn, have discovered that mixing cement, carbon black, and water in certain proportions results in concrete that doubles as a supercapacitor that is able to store electrical energy. I like how Professor Masic wraps it up.
“You have these at least two millennia old materials (carbon black and cement) that, when you combine them in a specific manner, you come up with a conductive nanocomposite, and that’s when things get really interesting.”, he says."
So, great. We have our ‘conductive nano composite’ – our own ‘flux capacitor’. Now what?
Well, the best place to start is to remember that we’re literally talking about something foundational. The foundation of a home, the foundation of a wind turbine, the foundation of a highway. If all of these things which were formerly structural are now sources of energy storage, well, that changes things.
Charging your car just by driving on the road
Doc Brown may have famously said, “Roads, where we going we don’t need roads”. But we still do, and we need electric cars to be easily charged. How about if that was done by … just driving? This has been attempted in the past (see this article about Sweden’s first swipe at it), but these required installing electrical rails in the road. Forget that – with supercapacitors, the job can be much easier.
The researchers propose an intriguing concept: integrating this technology within a concrete road could potentially facilitate on-the-go charging for electric vehicles, akin to the principles employed in wireless phone chargers. With this application, the road surface would become a battery while solar panels or windmills provide continuous power.
Don’t get too excited yet, though. There is more project work (development projects!) needed to get this to scale. The scientists have only produced a button-sized version of the material. Can’t drive too far on a button.
Also adding more carbon black does increase the power storage capacity of the material, it also decreases concrete strength. There will be research needed to find the ‘sweet spot’ – probably between 3 and 10 percent carbon black that retains enough of the strength of the material while providing the supercapacitor properties. No good having your car charged but falling through a carbon black hole.
Same deal for home foundations. It’s great if your home can store energy down there, but not so good if it falls over.
When capacitors fail they go with a bang. Old style televisions were notorious for this kind of failure, the loud bang which preceded the magic smoke was usually caused by capacitors suffering catastrophic dielectric failure, and releasing all their stored energy in a fraction of a second.
What concerns me is, if a TV capacitor explodes, abruptly releasing a few joules of energy, you spill your beer and curse a bit. But if a 10KWh household super capacitor goes, that’s 36 million joules of energy – equivalent to 8.6Kg of TNT, enough to turn your house into a sizeable crater.
10KW (10,000 watt hours) x 3600 seconds in an hour = 36,000,000 joules of energy 36,000,000 joules / 4,184 joules / gram = 8,604g = 8.6Kg of TNT
Even more interesting, brittle materials like concrete are vulnerable to mechanical shock. So that 8.6Kg of TNT equivalent, enough to utterly destroy a normal house, could trigger a chain reaction of adjacent dielectric failures, resulting in thousands or even millions of houses abruptly releasing their stored energy. And that’s not even considering the energy storage requirements of even greater concentrations of energy, like high-rise apartments and office buildings.
The failure of 115 adjacent household storage super capacitors holding 10KWh could release a kiloton of force – think the Beirut explosion in 2020. Worse, each additional household energy storage system recruited into the chain reaction and explosion would increase the risk to the next house.
I’m thinking, that would not be a good day to visit town.
Of course, all this risk could be mitigated by using expensive spring or rubber loaded mounts and shock resistant supports, to minimise the risk of the house foundation capacitor detonating because of an adjacent explosion. I’m sure no building contractor would be tempted to cut corners and use cheap, substandard shock protection components, right?
See an example of a capacitor blowing up in slow motion here (and imagine this scaled up by Doc Brown levels of magnitude).
This type of advocacy for ‘what could go wrong’ is so needed, and it’s best to consider this NOW, not after the first 10,000 kM of roadway and 300,000 homes are built.
So: more project work to do, but this is quite certainly a breakthrough that will lead us Back to a green Future.
