[Stoves] The PROTOS Plant Oil Cooker

[David G. LeVine]

At 03:35 PM 5/3/2007, you wrote:
>Low voltage LED solar lanterns. No heat,  no fumes,  no fiery deaths 
>for children or burned down houses. A small 4/6 Amp sealed battery, 
>a white automotive LED light assembly, and a very small solar panel 
>can be bought and assembled together for less money than one would 
>spend on kerosene lighting for a year.

Just in support, a small white LED runs around 20 mA, a 6 AH battery 
can supply 20 mA for 300 hours, however it is generally agreed that 
limiting the discharge to 60 hours will enhance battery life.  Still, 
that is about 5 nights easily.  There are much bigger LEDs, 5 Watts 
is common.  They put out a lot of light and a typical automotive 
battery will support one for 80 hours, however to enhance battery 
life, 16 hours is the recommended discharge level.  For the small 
light, charge times on a 1,000 MA solar array is 0.2 times the on 
time, excluding losses.  For the big (high output) light, it runs 
closer to 1:1.

I recently bought a LED flashlight with a "shake up" generator for a 
buck, I bet the housing and magnetics were a good part of that 
cost.  If the flashlight can be sold for $1.00 (US), a lantern should 
be no more expensive but solar cells are about $6.00(US) /watt or 
$30.00(US).  The solar cells are the killer, a bicycle powered 
generator might work.


David G. LeVine
Nashua, NH  03060