Comment by IanCal | Hacker News Reader

Comment by IanCal | Hacker News Reader

Parent Full thread

I think this will depend on the overall efficiency, but I can find portable reading lights at 1W, and I've got a 5W bulb in my hall. 20W is quite a lot for LEDs.

In general I agree, though I'd be interested to see the overall efficiency and output, whether your could get that kind of output from a larger plant.

I'm concerned about the (even theoretical) end to end efficiency compared to something like a solar panel + led setup.

> This technology could also be used to provide low-intensity indoor lighting, or to transform trees into self-powered streetlights, the researchers say.

Streetlights that glow up significantly sounds like a horrible idea for light pollution.

While interesting, and I'm happy seeing research done without clear monetisation, I'm not sure what key problems glowing plants actually solve. An honest question, as lots of smart people working on this I assume know a lot more about the issues than someone who's been thinking about it for 5 minutes.

> I'm concerned about the (even theoretical) end to end efficiency compared to something like a solar panel + led setup.

The maximum theoretical efficiency of chlorophyll-based photosynthesis with sunlight is 11%. That's already less than what solar panels can provide, and no plant achieves that. Then they store this energy in biomass, with a global efficiency of typically less than 1%.

Then, they will likely also use a very inefficient process to convert matter back into light, I'd assume less than 1% efficiency given the complicated pathways used. We're already at something like 0.01% efficiency from sunlight to artificial light at this point.

It's actually logical, since instead of converting light to readily-usable electricity, plants convert light into energy that they use to live, matter that they use to build themselves, and matter used for storage. Only the latest fraction is usable to create light, and most of it is already intended for the plant to live during the night. A solar panel has none of this overhead.

There is absolutely no way that plants will ever come close to competing with artificial lighting. They won't glow, at most they will be able to be faintly seen in the dark.

Thanks for the figures.

There's another general issue with this in that I can position solar panels to be best for receiving light and the bulb best for projecting it. A glowing leaf needs to do both.

Perhaps there are other good uses, if this can be targeted to specific issues with a plant (e.g. make it happen when they're being attacked by bugs, or need watering, or something like that) then it could be used as a signal we can cheaply detect.

If a plant glows while you're eating it, is it a cry for help??

Low-intensity indoor lighting could probably work.

I see the major problem in people being me and giving the plant water with the same regularity as rain the sahara, which means I can actually kill my desk lamp by not caring enough.

On the other hand, I've heavily abused my current desk lamp and it works.

It's great in terms of theoretical research but I think it might be a bit of stretch to think it could really replace a 2$ metal arm with a off-the-shelf LED strapped to it.

> which means I can actually kill my desk lamp by not caring enough

But now you have a nice reminder for watering your "lamp" when it isn't glowing as usual.

By experience; when a plant looks unwell, it's probably already dead and you have been watering a corpse. It's always the goddamn roots.

A common cause of death for quite a few kinds of plants is drowning. (or rather "too much water and the roots rotted away")

I'm terrible at taking care of plants but the last one I got was growing leafs until the last leaf stalk was completely dry.

Reply on news.ycombinator.com