geothermal storage is relevant to stirlings

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teraniageoff
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Joined: Thu Sep 28, 2006 12:42 am
First Name: Geoff
Last Name: Moxham

geothermal storage is relevant to stirlings

Post by teraniageoff »

Hi from down underOur group is called the Climate change action networkwe are planning on storing the heat from a tracked 3m dish in hot rocks.Estimated reservoir for household energy after one weeks rainy weather is 1 cu metre of dolerite/blue metal/basalt , held in a kiln like store with 6inces of durablanket. we believe this is the solution that sidesteps NiMH/Pb acid messy footprints.Collection is using 316 SS tube coil and op temp of 800 deg C superheated steam, vented to the bank so no pressure certificates are needed. separate load coil to Stirling.seriously wanting to collaborate internationally on an "Africar" type solution of a 3 kW linear alternatored Stirling.Our sane scientist is Alan Roberts MSc, who has written a program to design such stirlings, says we have finish the dish first.currently 1/2 way.watch this space.regards geoff
stan.hornbaker
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First Name: William S.
Last Name: Hornbaker

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Post by stan.hornbaker »

Things appear to be a bit out of line, e.g. 800-C surperheated steam can not exist below ~2800 psig! A question also arises as to the viability of a program that will design a real working 3 kW output Stirling engine generator combo. Next a 3 meter dish appears to be a bit small for the proposed use. Also the cubic meter of rock with only 6" of ceramic fiber is not likely to retain sufficient thermal energy to run a 3 kW output machine for a reasonable lentgh of time. Lastly an "Africar" Stirling would be no Stirling at all.
bptdude___2569
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Last Name: McLean

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Post by bptdude___2569 »


I have read about hot rocks and energy generation from U.S. lab sites. The American western states are sitting on a massive heat dome, one of the tips is the thing making hot springs here and there, but underneath is the heat of the planet in easy reach.

But, currently they only have been using test plants for steam type recovery. From what is published, Stirling cycle would yield greater percentage of recovery, in theory.

The published government reports state the energy reserves are at leaset several times all the oil reserves in the world.

No clue why 2 and 2 is not being added together.

Is global warming and energy independance not worth overcoming startup costs to offset that this won't be as cheap per kilowatt by next year's profit profile?

The cost per kiowatt is only about 30% more at current market prices.

teraniageoff
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First Name: Geoff
Last Name: Moxham

Response to geothermal storage is relevant to stirlings

Post by teraniageoff »

Hi William an Joe,

First to reply to William.
1).The pressures for superheated steam will be locally very high but diminish with
temperature and steam movement along the pressure tube. Alan Roberts says that 8mm
ID tube with 2mm walls in 316 SS has a bursting presure of 7000psi, so we are well within
limits here.
2). The storage for a powereddown house is calculated on 2 Kwh/day, not the business-
as-usual greed based madness that is currently masquerading as civilisation.

3).6inches of ceramic fibre is the innermost hot section and we intend adding several
outer low temp low cost layers in brick, and sawdust/shavings up to 12" thick ( I still think
in Imperial,sorry for mixed terms)

4). Our whole thrust is appropriate village-tech level of production, which like the Africar
can be serviced by moderately trained locals across the planet, rather than specialists
working in 1/ 10,000ths of an inch tolerances. To say this would not be a Stirling is the
same as aying the africar is not a car. It certainly wouldn't run on an autobahn, thank
heavens. Autobahns will be the choice of the elites, if they still exist after peakoil and
climate change bite for the next 10 years. However the africar was a vehicle , and provided
a local low tech solution, servicable with a shifter and a hammer. We intend to use the 20
years of tooling up the world has seen since then, and operate with tools that US high
school teachers might call "shop". 1/1000th inch will make a lovely Stirling, and if the heat
source is free (after set up) and storable, efficiency is negotiable.


To Joe.
2 +2 is a simple sum that oil CEOs, nuke CEOs, Coal CEOs and "earth is an infinite
resouce base " clueless economists still have trouble with. And we are all colluding in this
delusion if we accept it.
I post start of a humorous 12 step program for economic rationalists below:

Regards geoff

>#1. Look at a globe of the earth. Repeat one hundred times , Spheres are finite...spheres
are finite... spheres are finite... etc
> # 2. Put a piece of cake on a plate.
> # 3. Eat the cake.
> # 4. See if you still have the cake.
>
> Economists aren't used to empirical science and will have to do the
> experiment (#2 through #4) a few times before the implications finally
> sink in.
>
> Well kids, that's the First Law (the Conservation Law). Isn't science
> fun!!!

According to the 1st Law, they do still have the 'cake', but it isn't
cake anymore. Most of it will now be shit (along with some
transiently embodied chemical energy)

What economists have to discover and fully observe as they grasp the
2nd Law is a credible process for turning shit back into cake.
Otherwise we all end up eating shit.

They need to fully detail, and prove against 2nd Law Principles, a
market system that can reliably and durably convert shit into cake at
the same rate that the shit is being produced.
OR
Concede that Nature is both the cake, and the only credible process for
renewing the cake, and that economics, as it is practised, purposefully
accelerates the conversion of nature's cake into shit whilst reducing
the only known renewal process into the dead end of a stinking global
colostomy bag.
(from roeoz )
rgmco
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Last Name: Meloy

Response to geothermal storage is relevant to stirlings

Post by rgmco »

Geoff- Re: Shit-to-cake. One of the largest sources of "free" energy avaiable to us is the methane gas in what we delicately call human waste. It will not be long before we begin to convert our waste water treatment plants into power plants. I believe this source of energy may, in fact, be "infinite", even on a sphere.

Dick
rgmco
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Last Name: Meloy

Response to geothermal storage is relevant to stirlings

Post by rgmco »

Incidentally, the problem with geothermal energy is not converting it to power, but simply getting it out of the ground. Drilling for heat is a lot like drilling for oil- you know it's there, but you aren't going to be successful on every well. Hence, the cost of developing a reliable stream of hot water from hot rocks is 1)hard to predict and 2) often very expensive. Disclaimer- I am not an oil company executive, but I used to try to finance geothermal projects!
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