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Comment by deltarholamda | Hacker News Reader

They are new to Cree, who is a more mainstream manufacturer.

The growlights that power the vertical farms (which are, let's be honest, mostly weed farms) come from vendors (e.g. Fluence) that are more specialized, and therefore are fairly expensive. About $1500 per 4x4 foot grow area, last prices I saw.

I dunno if this will ever be economically feasible outside of high-value crops. A Spyder rig from Fluence draws about 630W. But yep, it is at least a step forward, and way better than the weird fluorescent/MH/HID options.

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How is $1500 per 4x4 area possible? My 4x4 tent is somewhat over-lit using brand new Samsung LEDs with a dimmable, low-heat, high-efficiency fixture and it cost me more like $800 CAD. What do these lights do that mine doesn't?

The actual power draw on mine is about 460W according to a kill-a-watt, which seems like plenty for a 4x4 space using high quality LEDs. 630W seems like far too much, but I'm also a relatively clueless hobbyist. This light certainly grows lettuce and herbs really well, but maybe it would be terrible for tomatoes/cucumbers/peppers.

has anyone compared energy using LED used in growing plants? sure sun is free but in winter conditions or at night for example? would it be more cost effective to keep plants in the sun during the day and give artificial light at night so that they keep growing 24x7?

Most plants need a dark period in order to grow well. You don't actually want 24x7.

A lot of northerly greenhouses use sun + supplemental lighting to keep the day length long for maximum growth, however, while not paying to keep the lights on all day.

Many years ago I saw supplemental light used in commercial hothouses to extend the day. (~49°N)

When the sun was setting, they came on and gave a few more hours of light.

There's also the bonus of waste heat.

>How is $1500 possible

The fixtures are sold as a for-product solution. They are set up to have flex connectors so the plants can be put on movable racks (with multiple levels) and share power supplies. They are definitely not a hobbyist thing. Think of them as the Cisco switches for growing dope.

There's also some woo-woo about specifically tuned frequencies. This may or may not be a Real Thing, that's not in my wheelhouse.

>630W

They have multiple watt ranges. Another set is more like 340W. The 630W is more for the flowering stage.

I have never grown or used weed at all, but I have done the electrical design work for a largish facility. It's all really fascinating, but it is also a niche market that has a lot of "dude, weed" guys at all levels.

Nice, thanks for filling in the gaps there. This makes a lot of sense. Such a fascinating industry!

I think you might be confusing lighting fixtures (what fluence makes) vs actual leds (what cree does). I suspect fluence is probably using osram leds for their products.

IIRC Osram bought Fluence, so they're all Osram now.

Cree also manufactures lighting fixtures. They are routinely specified.

My point on the "sci-fi scenarios" was more for crewed exploration and settlement of space in the medium and long term future.

While there are plenty of other reasons to be skeptical about that, the ability to supply them with some fresh food without requiring magic biotechnology is certainly one barrier crossed off the list.

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