The Ever-Present Glow of LED Greenhouses

Re:The Ever-Present Glow of LED Greenhouses by Roark66 on Wednesday October 23, 2019 @06:33AM (#21333171)

The problem would be that those narrow band glass filters would also block those narrow bands in daylight needed by the plants. They would have to have those LEDs on 24/7 which means a greenhouse is no better than a basement with no daylight.

I think they should simply use curtains or shutters that close at night. I'm surprised a modern country like Netherlands has no laws regarding light pollution.

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Re:The Ever-Present Glow of LED Greenhouses by the8472 on Wednesday October 23, 2019 @09:19AM (#21334312)

I was actually talking about glasses for humans, but I will roll with your argument anyway:

Plants are not narrow-band absorbers. They can utilize rather wide ranges of red and blue light. So if you blocked out a very narrow band there they would still get most of the sunlight. During the night they would simply harvest photons from those narrow bands, they don't care. But the photons wouldn't escape the glasshouse.

But yes, shutters are probably much cheaper than narrowband light sources and matching filters.

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