highway sign lighting using solar

[MrDEB]

I am involved with the Knights of Columbus, a catholic men's organization that are purchasing 3 billboard signs for our PRO-LIFE campaigne. Going to erect at the three entrances to Salmon, Idaho.
Signs are 8ft x 16 ft. Would like to light them up but using solar power for electricity.
Ideas I have are to use high wattage LEDs powered using PWM to save on electricity consumption.
Second idea is to have a headlight sensor that when a vehicle approaches the sign light up for a short period.
Just starting to research this project seeing how the quote I got from a company in Florida is $12000 with $975 shipping.
Just starting research but trolling for ideas.

 

[alec_t]

Not wanting to rain on your parade but have you considered the safety implications of this? Even a non-illuminated billboard is a distraction for motorists who should be concentrating on driving. A billboard which suddenly lit up would be much more distracting. You wouldn't want accident victims on your conscience.

 

[Reloadron]

If you go the PWM route consider dimming proportional to daylight. Something else to consider is state laws regarding signs that turn on based on headlights as in you don't want to freak out drivers and get a lawsuit. Were you thinking along the lines of LED floods to illuminate the sign? It's a large sign so I am unsure how practical verse cost LEDs would be?

<EDIT> Alec beat me with the safety aspect. by two min. </EDIT>

Ron

 

[k7elp60]

Mr Deb,
You may want to contact Young Electric Sign Co.(Salt Lake City),as they have a number of solar powered signs North of Las Vegas on I-15.

 

[audioguru]

Can anybody see LEDs in sunlight? Or will the sign light only at night from a battery charged by solar energy?
Why dim the LEDs? PWM dims them so that their average current (and average brightness) are less.

 

[atferrari]

A real concern

A billboard which suddenly lit up would be much more distracting.

I agree on that.

 

[OlPhart]

I suspect LED is illumination, not image source. Unfortunately, solar power in -> illumination out isn't an easy call. There're a bunch of factors involved, good luck solving it; I've been working on one project >1yr between NiCd issues & solar panel size: it's being tough. <<<)))

I think it was mentioned... headlight sense causes soft up of brightness, timeout causes soft off...

 

[colin55]

The sign can illuminate slowly, so I don't see what all the fuss is about.

You need to know the illumination-level to make illumination worthwhile.

Our solar powered night-signs are powered by simple 4ft fluorescent tubes. But they are not very bright.

 

[MrDEB]

This project is in the circulfile as the LEDs are $12.95 each x 8 plus the solar pannel and battery = $12000 per sign