Questions tagged [light]

Sustainable sources of and use of light, whether natural or artificial.

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Is it true that nitrate radicals improve air quality during the night (and that is why light pollution, which destroys them, is bad)?

Is it true that nitrate radicals improve air quality during the night (and that is why light pollution, which destroys them, is bad)? I just came across this old presentation on light pollution from ...
Sergey Zolotarev's user avatar
2 votes
2 answers

What materials to use indoors to absorb sunlight and store it as heat?

(Also asked in Engineering Stack Exchange) I'm buying a new place in the northern hemisphere (49° N) with lots of southern (or rather SES) exposure. I'm putting quite a bit of thought (together with ...
H A Helfgott's user avatar
2 votes
1 answer

Simple solar light system

I've been looking for a simple solar powered lighting system for a carport I just built. I bought these without realizing how small they are: 2 Pack Solar Lights Outdoor. Unfortunately they look ...
Dan's user avatar
  • 131
1 vote
2 answers

How can I tell if my light is insect friendly?

This time of year, on my commute home through the forest, I need a bright headlight for me and other humans (and some wildlife) to stay safe. However, research suggests that night lights kill many ...
gerrit's user avatar
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3 votes
1 answer

Do light fixtures with small solar panels require direct sunlight?

I purchased an Osram Ledvance DoorLED Solar product which charges its own batteries and turns on automatically at nighttime to provide light. It requires a 7 hour minimum charge time. When there is ...
Sabuncu's user avatar
  • 133
0 votes
1 answer

I have got some lights for hydroponic growing, they run from the UK mains but have small clover shaped connectors - what are these called?

I just got a load of LED grow light tubes - they have mains connectors that use clover shaped plugs -- very much like a lot of laptop chargers use, but just a bit smaller. There is no label on the ...
pperrin's user avatar
  • 145
5 votes
5 answers

Why are my LED light bulbs so short lived?

I thought the idea of LED is, that the light bulb has a very long life and uses very little electricity. I have not invested in full LED lighting but tried the LED bulbs, you screw in your normal ...
user1721135's user avatar
4 votes
1 answer

Large-scale test data on LED, CFL, and incandescent brightness and longevity

A google search for "comparing LED, CFL, and, incandescent brightness" returns hundreds of charts showing what equivalent wattage of LEDs and CFLs are to match an incandescent bulb. This is fine for ...
LShaver's user avatar
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15 votes
2 answers

Should I replace existing inefficient light bulbs?

Similar to this question (except that's about cars), if I can buy more efficient light bulbs than the ones I'm using right now, should I? Or is it better to wait until my current light bulbs expire, ...
Alex Hall's user avatar
  • 313
7 votes
2 answers

Anything similar to GravityLight that can be readily purchased?

Ever since it was first mentioned in a popular news site, I've always been interested in GravityLight. But I've never been able to go to a store or a site and just buy it. Is there anything vaguely ...
rbhat's user avatar
  • 331
12 votes
3 answers

Is it economical / sustainable to switch from CFL to LED?

In my house, I currently have a mix of incandescent, CFL, and LED bulbs. I have a supply of additional CFL and LED bulbs. My immediate plan is to go through the house and swap out the incandescent ...
Sean Duggan's user avatar
6 votes
1 answer

Energy requirements for sustainable food production system

Overview Consider the following system for sustainable food production: The purpose of this system is to provide an environmentally-friendly, semi- (or fully-) automated means to produce food for ...
Dave Jarvis's user avatar
3 votes
1 answer

Can artificial lighting compete with horizontal agriculture?

Background In Professor Bugbee's presentation, he describes some drawbacks of vertical farming (VF) versus traditional horizontal agriculture. Most of Bugbee's arguments against VF hinge on grow lamp ...
Dave Jarvis's user avatar
3 votes
1 answer

How much energy could we save if we all got up at sunrise

Just had a thought: How much energy could be saved if everyone got up at sunrise? Perhaps it would have a counteractive effect somehow but my thought is that if you're up less during hours that it's ...
Trav's user avatar
  • 295
31 votes
9 answers

What to do with old, unused incandescent light bulbs

Over the years, my family has built up a small stockpile of incandescent light bulbs. More recently, we have been replacing our incandescent lights with more energy-efficient alternatives. ...
Lily Finley's user avatar
1 vote
1 answer

Energy saving lamps suggestion

My dining room lights are shown in the pictures. I have two of those fixtures, with 3 bulbs each. 1) On the plastic chandelier it says "MAX 40W", but the lamps that when I first arrived in the flat ...
usumdelphini's user avatar
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2 votes
1 answer

How much heat loss occurs due to unsealed downlights?

I would like to convert my downlights to LED. However, the LEDs I've found have holes around them to let the air though. I've been told this is for ventilation purposes and blocking these holes or ...
dizzy's user avatar
  • 280
17 votes
2 answers

Are incandescent light bulbs recyclable?

Can standard incandescent (i.e., non-energy-efficient) light bulbs be recycled? If so, what is the best way to recycle them?
luna_moth's user avatar
  • 380
-5 votes
4 answers

Solar energy without the sun: Super LED light on top of solar panels? [closed]

Some questions: Can LED light provide same amount of energy as sunlight? Can humanity get rid of the sun and charge solar panels from LED light alone? If this is feasible, this would be truly ...
Level1Coder's user avatar
2 votes
1 answer

Repair a bedside lamp

My beloved bedside lamp fell down, on the carpet so it wasn't a big hit, and it stopped working. Now, I tried to replace the bulb, but it doesn't change anything. Since this had happened to me ...
usumdelphini's user avatar
  • 1,121
9 votes
1 answer

How do I dispose of Xenon light bulbs?

I have some under-cabinet lighting that uses Xenon G8 bulbs. I didn't even know this type of light bulb existed until recently. One of the bulbs has stopped working and I want to get rid of it. What ...
Alnoor's user avatar
  • 93
14 votes
3 answers

Sustainability of LED production?

Not all LEDs are the same. Standard LEDs use various combinations of indium, gallium, arsenic, silicon, phosphorus, zinc, selenium, and a couple other elements. Most of these need to be mined from the ...
Evan Johnson's user avatar
  • 1,856
7 votes
2 answers

Indoor Urban Garden Lighting

Is there a specific type of light source that outperforms others for indoor urban gardens? This could be a combination of power usage and its effect on growing plants (i.e. spectrum it produces).
TomSchober's user avatar
13 votes
2 answers

How much energy does it take to create a single light bulb?

This question is a part of this question. Perhaps it is better suited on the physics SE, but here goes. I would like to know how much energy it takes, in the modern world, to construct an ordinary, ...
Rody Oldenhuis's user avatar
26 votes
5 answers

What form of electrical lighting has the smallest energy-footprint?

We all know that when it comes to household electrical lighting, LED lights consume the least amount of energy for a given amount of light, followed by fluorescent tubes, halogens, and Edison-age ...
Rody Oldenhuis's user avatar
12 votes
2 answers

Improving natural light access

I get relatively little natural light into one room as shown below (this is the only window): Is there a way to increase natural light into the room so that I don't have to use the electic light ...
Joe's user avatar
  • 1,269
16 votes
6 answers

Are there any bright candelabra base LED bulbs equivalent to a 60-75 Watt incandescent?

My fan takes 3 candelabra (E12) base bulbs; I traditionally use incandescent flame tips, but since they're behind frosted glass, I don't really care. Having just replaced my dimm-able recessed ...
JoshDM's user avatar
  • 265
17 votes
1 answer

Long-term sustainability concerns of compact flourescent vs incandescent light bulbs

There is a strong movement to push people away from using incandescent lightbulbs in favor of compact flourescent bulbs in order to save energy, but the pollution profiles of these bulbs are very ...
Chris Travers's user avatar
22 votes
2 answers

What's the typical energy usage of automatic light switches?

A good way to cope with forgetting to turn of the lights is automatic light switches. But they must be using some energy to do their job. What's the rate of energy use for a typical automatic/sensor ...
Rob Mosher's user avatar
  • 1,035
34 votes
2 answers

What’s the best strategy for turning off CFLs that will save energy but not reduce lifespan so much

With ordinary bulbs, I was used to turning the lights off even when I left the room for a few minutes (mostly because I know that I'll find other business and forget to return :-) ), but I've heard ...
Pavel's user avatar
  • 993