Re: Storing the summer heat

From: Michael Moroney (moroney_at_world.std.spaamtrap.com)
Date: 11/22/04 

Date: Mon, 22 Nov 2004 17:22:40 +0000 (UTC)

The Ghost In The Machine <ewill@sirius.athghost7038suus.net> writes:

>In sci.physics, habshi
><habshi@anony.com>
> wrote
>on Sun, 21 Nov 2004 01:42:03 GMT
><419ff198.1014588@news.clara.net>:
>> What is wrong with the idea of storing summer heat
>> underground?

>So let's assume SimplePlanet has 180 days hot weather (30 C),
>and 180 days freezing cold weather (-10C). Dig an underground
>thermos vault 10m x 10m x 10m and fill it with 1,000 metric tonnes
>of 30C water. Total usable heat storage capacity would be 10^10 cal
>or 41.80 teraJoules, since we want 20 degrees C water at least
>to come out.

>The walls here would be 600 m^2 total. This means K for this vessel
>would be on the order of 10^-5 * 10000 / 10^9 = 10^-10, and
>assuming the Simpletons didn't touch this nice heat vesicle,
>the temperature of the water just before summer starts again
>would be

>-10 + 40 * exp(-180 * 86400 * 10^-10) = 29.938

Out of curiosity, what would the necessary R value be for the theoretical
insulation needed to insulate this heat storage unit? 

-- 
-Mike