This group has come up with a process for building new coral reefs. It involves wire-mesh frameworks, low-voltage currents creating mineral accretion, and the transplant of broken pieces of coral.
I have no idea if this really works, or how it compares to the proven tactic of creating artificial reefs by sinking ships. But given the importance of coral reef ecosystems (they're the rainforests of the oceans), and given how close to collapse they are, everywhere around the world, creating some more tools in a restoration toolbox seems like a good idea to me.
Apparently, the idea could also be used to create buildings made from coral then pulled out and placed on dry land.
Wolf Hilbertz has been working on this idea for at least a decade. I saw him give a presentation at least that long ago where he showed how to make building material by electrical deposition.
Bruce Sterling mentions the technique in _Islands in the Net_.
Posted by: gmoke on April 6, 2004 6:34 PM
Yes, certainly these folks aren't the first to think it could be done - but they are the first I've come across who are actually *doing* it.
I'll have to go take a look at Wolf Hilbertz's work.
This is indeed an effective way of rebuilding reefs, from what I've read. However, it is not a reasonable building technology. It is more energy-intensive to make than concrete (which is not a green building material to start with), and takes a hell of a lot longer to form. Time to accrete a 1.5 kg mass, 1 liter volume "flower pot": 5 years. With higher current, accretion time could be as short as 8 months, but "The flower pot made at this higher current density would be expected to be nearly 100% Mg(OH)2" (which may be less strong than CaCO3) -- http://www.stanford.edu/~erlee/seament/sm_reslt.htm
It's also cost-prohibitive: Again according to Eric Lee at Stanford, it accretes .046kg/kWhr, which, assuming electricity costs $.05/kWhr, means that it would cost $2.40/lb to make. Concrete costs $.03/lb. He thinks that 1kg/kWhr is theoretically attainable, which would be $.11/lb. -- http://www.stanford.edu/~erlee/seament/sm_preq2.htm
worldchanging was founded on the idea that real solutions already exist for building the future we want. it's just a matter of grabbing hold and getting moving.
This group has come up with a process for building new coral reefs. It involves wire-mesh frameworks, low-voltage currents creating mineral accretion, and the transplant of broken pieces of coral.
