Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!wuarchive!mit-eddie!ll-xn!killoran
From: killoran@XN.LL.MIT.EDU (Mike Killoran)
Newsgroups: sci.electronics
Subject: How practical is solar for remote application?
Message-ID: <1790@xn.LL.MIT.EDU>
Date: 9 Apr 90 20:49:43 GMT
References: <1990Apr4.030429.15518@ux1.cso.uiuc.edu> <55134@bu.edu.bu.edu>
Reply-To: killoran@xn.UUCP (Mike I. Killoran)
Organization: MIT Lincoln Laboratory, Lexington, MA
Lines: 17

Greetings,

I have an application which will use about 7Watts at 5Volts.  I would like
to have this in operation 24 hours a day for as long as possible unattended.
My thinking up to this point has been to use batteries, replacing these as
needed.  However, solar might become an interesting alternative depending
on the difficulty.  Since this has to operate at night, I assume the solar
array will have to produce enough energy to power both the device during 
the day and charge batteries at the same time which will discharge into the
device at night.  How do I figure the best batteries and the size of an array
needed for this application taking into account inefficiencies of solar
cells, batteries, etc.?  This will be in a HIGH sunlight area.

Sorry if this is asking for a simple answer to a complex problem, but at this
point I am just trying to see if this idea will pan out.  Thanks,

Mike Killoran