Subject: Solar Ovens

From: [email-masked] (Ray C. Cole)
Date: Sun, 02 Jul 1995 22:15:07 GMT

I expect to go to Indonesia in the near future with the Earth Watch
organization. I will be on one of three teams building about 100 solar
ovens and introducing these to the residents of Lombok island, off of
Bali. In theory, this should make an impact on the number of trees
being burned to make charcoal as the current source of energy.

Is there anyone in this group that has had experience in such projects
in the past. I am trying to get as prepared as possible prior to
departure in mid-July.

I would appreciate an early reply.

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From: [email-masked] (Nick Pine)
Date: 4 Jul 1995 09:59:29 -0400

Horacio Gasquet  <[email-masked]> wrote:

>There is also a need in the third world for water treatment.  There are 
>efforts to use solar to distil water.

There's a need here too. About 90% of the land in Pennsylvania is unsuitable
for a conventional septic system, and sand-mound-compatible sites are scarce 
too. I read about an interesting system for sewage disposal for a group of
26 houses in a new development, that got around regulatory problems by
building a large greenhouse and growing reeds, which _evaporated_ all the
influent from the houses. This "evapotranspiration system" was designed by
a local PE. Since the greenhouse had an impervious rubber floor, the PA
Dept of Env. Resources didn't have much to say about permissible effluent
limits, in the form of Biological Oxygen Demand (BOD), suspended solids
or nitrogen as ammonia... But it seems to me that this is a great waste
of solar energy, compared to a closed system that is capable of recovering
most of the heat (some 1000 Btu/pound) that is used to evaporate the water,
eg by heating incoming water, and recycling the distilled water. 

Does anyone know of a system for solar water distillation like that?

Nick

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From: Tu and Bob Myers <[email-masked]>
Date: Wed, 5 Jul 1995 11:14:50 -0400

Try:  Back Home (Magazine)
      Backwoods Home (Magazine)
      Home Power (Magazine)
      Mother Earth News (Magazine)
      Kansas Wind Power (Company)
      Lake Michigan Wind and Sun (Company)

There were articles on solar distillation in the Caribbean (sp?) in one 
or more of the magazines.  I believe one of the two companies sells/sold 
commercially built versions of the distiller described below, in 3 or 
four sizes.
 
Solar Distiller Description

Basicly the distiller is a flat table 4' by '4' (4' by 8') with walls.  
The walls are about 6" high in front and about 12" in back, and slanting 
on the sides.  The distiller is covered with glass pane(s).  There is a 
fresh water collection trough on the front wall about 1" below the 
glass.  It has a hose leading to a fresh water container.

Operation

The table/distiller is filled about half height with salt water.  The sun 
heats the water which evaporates and collects on the glass (which is 
colder than the air and water in the distiller).  Because the glass is 
slanted from the front of the distiller, the condensed water moves to the 
front of the glass/collector and falls into the unsalted water collector, 
thence to the fresh water container.

At, or after, sunset the distiller is drained to get rid of the salty 
water which is saltier because of the water that was removed.  Rinsing 
with new (less) salty water helps.  Then the distiller is refilled with a 
new charge of salty water for the next day.

I don't remember the average daily output.

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From: A Salem <[email-masked]>
Date: Fri, 07 Jul 95 12:47:35 GMT

> I don't remember the average daily output.
Does anyone have a copy of any of the above named articles or know the address
of the above magazines/companies?

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From: [email-masked] (Alan Crabtree)
Date: Fri, 07 Jul 1995 23:26:05 -0700

> of the above magazines/companies?

Home Power magazine has archives at the URL below and has had several
articles on solar cooking (and possibly distillation) in the past. There
is also contact info for them.

ftp://sunsite.unc.edu/pub/academic/environment/alternative-energy/energy-resources/homepower-magazine/

-- 
Alan Crabtree  ([email-masked])
Visit The Gorby Files
Newton, Snohomish County (WA), renewable energy and Gorby!
http://www.halcyon.com/alancrab/gorby.files.html