Interesting project.
Please post more pictures to show how you dealt with some issues...
Looks like sheet metal with the "sign" cut out. Very nice job...
How did you address the issue of having something behind the cutout
to defuse the light so it doesn't look like a bunch of led dots?
Ditto for the issue of being opaque enough so that it looks nice
when front illuminated by the sun?
Would also be interesting to see how you mount it all to look aesthetic
yet not be a target for vandalism, theft, weather damage etc.
Looks like a public space, probably owned by the city. What kind
of permits did this require? Did they make you buy liability
insurance in case the solar panel falls on somebody?
I helped with some mountain-top solar-powered radio repeater sites.
They had to provide proof of liability insurance even though the
site was behind locked gates on a mountain top.
The logistic and liability issues were far more hassle than the actual
installation. The wind generator was a popular target for hunters
and hikers. Fortunately, they didn't seem to want to shoot the solar
panels.
How are you going to handle the on/off of the LEDs? Low voltage
disconnect to avoid damaging the battery over a week of cloudy days?
I did some back-of-the-envelope calculations based on info provided
here, what I could glean from the data sheets and a liberal amount
of pulling guesses out of my numbers orifice ;-) Someone will
surely check my math.
I did the math for the 5630 case, but the concept scales.
Looks like the modules want 60ma at 12V. If they're what they
look like, there's gonna be a 52ish ohm resister in series with the
string of 3. About 30% of the power is in the resistor at 12V and
not providing any light.
Depending on the setting of your charge controller and the depth
of discharge you allow, the actual voltage may vary between 11
and 14V. That's 41 to 99ma...over 2:1 in brightness and may exceed
the LED power limit at 14V. How you deal with that may have
significant impact on the battery capacity you need.
At nominal 12V 60ma, you get about 180mW per led.
600 leds is 108W of power actually producing light. The other
36W is just heat.
Nominal light output is 124 lumens/watt x 108W = 13392 lumens.
Divide that by 800 and you get 16.74.
So, the light output at 12V is equivalent to about 17 60W incandescent lamps.
That puts it in terms with which we're all familiar.
And that will vary 2:1 depending on the output voltage of the battery
over the time it's being discharged.
You probably lose half of that in the medium between the LEDs and the
sign that makes it look nice both night and day. And more in the overlap
behind the metal part of the sign, depending on how the size of the
array lines up with the "sign" part of the metal sheet.
Almost all of that 144W shows up as heat. Don't forget to measure
the temperature of the modules at max voltage to see if you need
to heat sink them.
If you choose the dimmer LEDs, I think everything just about halves,
but I haven't done the calculations to prove it.
Are we having fun yet?
Post more pix please...
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