Dear Solar Guy,

        One thing I'm surprised about is why we don't see more solar water
heaters installed on roofs of houses.  I thought solar water heating was
considered economical.   

J.B. in Wink.

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Dear J. B.,

        Yes, I would agree.  Solar water heating has a reasonable pay-back
against electric water heating and is marginal against natural gas.  The
economics also improve the further one is located away from the coast.  So
why don't more houses have solar water heaters?  There are a number of
reasons, but none of them very good.  Some home-owners are concerned about
the aesthetics, but a collector can be screened pretty well, but why hide
it and instead advertise it?  Improper roof orientation is sometimes
expressed.  But a former colleague coined Will Rogers by saying he's
"never seen a roof he couldn't put a solar collector on", and have it perform
satisfactorily.  Note although south facing is best, little performance is
lost if within 30 or 40 degrees of south and little, and although a tilt
of latitude plus 10 degrees is best there is little performance penalty if
with 10 or 15 degrees of that.  Some claim solar water heating is
unreliable, but since either electric or natural gas back-up is part of
the system, it should be just as reliable as conventional.  In fact one gets a
longer supply of hot water because of the greater total storage volume.
Lastly, while the payback is not as short as we would like, it is still
reasonable.  Maybe we should start with a campaign to get our members to
install a solar water heaters ?  Wouldn't that be revolutionary!     

The Solar Guy.