[extropy-chat] FWD [PvT] Re: Anti-hurricane engineering

[Hara Ra]

I was musing about the problem today:

1) If the air bubbles are put into the water, I have totally ignored the 
fact that 100 meters of water is about 10 atm pressure, and when air is 
compressed this much it becomes hot (think diesel engines compression 
ratio). The energy to compress the air is not avoidable, and once the air 
enters the water there is no means to keep the air hot.   I don't want to 
to the math, but compressing 1 M^3 of air to 100atm (10 liters) takes 
vastly more energy than lifting 1 M^3 of water by 1M.

2) However, if the device floated on the sea, so we don't have to go to the 
pressures of the abyssal depth, how about simply putting the pump at the 
bottom of a 100m tube. Now the efficiency is around 90%.

3) If we distribute pumps every 100 meters, it takes 100 pumps per Km^2, 
with 270 wh per pump. That's an average of 2.7 watts if it takes 100 hours 
to run the pump. This is about the power of your typical solar panel for 
keeping the charge on a car battery. Produced en masse (100 million units 
for 1 MKm^2) the per unit cost should be under $30.00 - a $3 billion cost. 
Just use a simple thermostat, and no battery, no signalling, and the upper 
part is an inflated tube and the tube in the water is 3 mil plastic.

4) This design would not be a navigational hazard, but I am sure some 
delicate species will have a hard time. (Maybe they will constipate 
sharks). Such devices are not expected to last more than a season, they 
will foul with mussels and the like.

5) The sea is a very large place, and hurricanes go lots of places, so 
there would have to be a delivery system capable of dropping these within a 
week, and some kind of recovery process at the end of the year.

6) The conservative approach is just to build stronger buildings.

>--- Hara Ra <harara at sbcglobal.net> wrote:
> > Not quite.... The cold water is denser than the warm
> > and must be lifted<snip> This is a
> > negligible heat load but a significant ($2.7 million
> > at $100 /Mwh) power cost for the lifting alone.

>So...would another way to accurately state the problem
>be, this might become practical if energy became a
>lot cheaper than it currently is?
>
>(Although, merely $2.7 million is less than some
>insurance companies pay in claims for a hurricane's
>damage, so this might be worth it to them to stop or
>seriously reduce a hurricane if the non-energy costs
>are not significantly more than that.)
>_______________________________________________
>extropy-chat mailing list
>extropy-chat at lists.extropy.org
>http://lists.extropy.org/mailman/listinfo/extropy-chat

==================================
=   Hara Ra (aka Gregory Yob)    =
=     harara at sbcglobal.net       =
=   Alcor North Cryomanagement   =
=   Alcor Advisor to Board       =
=       831 429 8637             =
==================================