Posted by Winston on January 12, 2012, 7:49 pm
danny burstein wrote:
> Just got this offer from Amazon and it sounds like
> a decent match for what I'm planning.
> We want to set up an outdoor LED fixture (ok, it'll
> be a menorah/candelabra) using a total of about 20
> watts of LED lighting.
> It'll be on a timer, so only be lit for 2 or so hours
> after sunset. Hence 40 watt-hours/day.
> Assuming they're telling the truth and this panel would
> provide 50 watts in direct sun, that would (rule of thumb)
> get us about 200 watt-hours on sunny days, and maybe
> a quarter of that on a typical foggy/misty one.
> Even if they're optimistic and doubling the real number,
> we'd still do ok.
> So... attached to a 500 watt-hr battery, that would
> get us through a week, or even two, of drizzle...
> Anyway, the price looks good, at $19.00. Throw in a decent
> controller gets us into the $00 range. Batteries would
> be extra, of course.
You will want to include security costs, too.
A motion-sensing webcam to post pictures of
the guys who walked off with your panel,
battery and controller.
Then you get to trench for a 24 V power line anyway.
Unless the display is in the middle of an island,
photovoltaics will be a waste of money IMHO.
--Winston
Posted by Jim Wilkins on January 12, 2012, 11:58 pm
> Anyway, the price looks good, at $19.00. Throw in a decent
> controller gets us into the $00 range. Batteries would
> be extra, of course.
> >
> Thoughts?
http://www.harborfreight.com/interests/solar-power/two-pack-solar-spotlight-set-95745.html
I don't have that one, but the other HF solar lights I own work reasonably
well. They are screwed together and were pretty easy to disassemble and
customize. You might as well order spare AA NiCads as the ones they come
with may fail soon.
jsw
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> a decent match for what I'm planning.
> We want to set up an outdoor LED fixture (ok, it'll
> be a menorah/candelabra) using a total of about 20
> watts of LED lighting.
> It'll be on a timer, so only be lit for 2 or so hours
> after sunset. Hence 40 watt-hours/day.
> Assuming they're telling the truth and this panel would
> provide 50 watts in direct sun, that would (rule of thumb)
> get us about 200 watt-hours on sunny days, and maybe
> a quarter of that on a typical foggy/misty one.
> Even if they're optimistic and doubling the real number,
> we'd still do ok.
> So... attached to a 500 watt-hr battery, that would
> get us through a week, or even two, of drizzle...
> Anyway, the price looks good, at $19.00. Throw in a decent
> controller gets us into the $00 range. Batteries would
> be extra, of course.