LED Bulbs

[MikeG]

I can't believe the number of people who are talking about leaving lights on all day. It's completely crazy! If you really find switching a lightswitch on and off too taxing, PIR switches are cheap and common, and with a timer set correctly, will turn the lights on and off for you simply through sensing your body heat.

I guess the same sort of people who leave lights on 24 hours a day have the thermostat set to 25 or 26 C and walk around in mid-winter in shorts and tee shirt.

 

[macdoc]

You have a problem with leaving a 3 watt light on ????

I'm all for energy savings but there are limits.
We have no fossil fuel component in our power ...perhaps it's a different perspective.

Electrical ower is there to serve certain purposes and leaving several 3 watt task lamps on in various rooms with people coming in and out at all hours, gear around etc the safety and convenience outweighs turning a 3 watt task light off.

Using a dryer and washer and dishwasher at night - sure, decent savings to be had...that's purely financial tho not environmental. Leaving a CFL outdoor light on is useful as well. Emergency services can see the house number and the street is more welcoming at night with some house lights on.

Not all houses tolerate heat well either...what is comfortable in Cairns in an open architecture Queenslander is not in a smoggy hot city.

Staff need to be comfortable to work and clients comfortable when they come in. It's a cost of doing business.

I'm quite happy that Ontario eliminated coal entirely. Puts more of an emphasis of reducing fossil footprint on vehicle use rather than home.

 

[MikeG]

You have a problem with leaving a 3 watt light on ????

Yes, but of course that's not what most people are talking about. Exterior lights are never 3W, and light pollution is just that.

We have no fossil fuel component in our power ...perhaps it's a different perspective.

That's great, and of course it's a different perspective, but I would still be saying save power wherever possible, and export the savings to somewhere that doesn't have such clean electricity supplies.

Electrical ower is there to serve certain purposes and leaving several 3 watt task lamps on in various rooms with people coming in and out at all hours, gear around etc the safety and convenience outweighs turning a 3 watt task light off.

This doesn't sound like a domestic situation. I was talking about houses: saving power at home. In a workplace, it is of course a different thing, although PIRs work beautifully there too.

Leaving a CFL outdoor light on is useful as well. Emergency services can see the house number and the street is more welcoming at night with some house lights on.

That's still wasteful and polluting, including light pollution. If the emergency services are called, then by all means turn an outside light on. If you go outside at night, turn the light on. Otherwise, I can't see a single good reason to light up the dark when you are asleep.

Not all houses tolerate heat well either...what is comfortable in Cairns in an open architecture Queenslander is not in a smoggy hot city.

I'm not sure what you are getting at here. However, in broad terms, if you have a house that is wasteful of warmth (or coolth), then sort the house out. insulate. Ventilate properly. Install better windows. Don't just pour energy out through the building fabric.

I'm quite happy that Ontario eliminated coal entirely. Puts more of an emphasis of reducing fossil footprint on vehicle use rather than home.

In broad terms, houses use roughly a third of this country's energy, transport a third, and industry a third. If Canada is anything like the same, why would you put more emphasis on saving energy in transport than on eliminating domestic wastage?

 

[PossumPie]

But politicians "legislate" what they think is best without all of the facts. In the USA, they demanded oil companies to use a percentage of Ethanol in gasoline. Patting themselves on the back, they didn't realize it destroys small engines. Now people are throwing away leaf blowers, weed whackers, lawn mowers, chainsaws in record numbers. Seems the ethanol corrodes the inner workings. The fuel efficiency is LESS in ethanol, so we use more. The agricultural impact has not been beneficial. I'm Libertarian. Give me alternatives so I can make good CHOICES but I resent politicians telling me I HAVE to use CFL/LED lights and Ethanol gasoline. Sometimes the eggheads are wrong and the environmental impact of their do-good laws just make things worse. Governmental intervention in our lives almost always makes things worse.

 

[bruto]

A QUARTER the power !!!!????- how about 5% of the power. Our task lights are 3 watts....against a typical incandescent of 60 watts PLUS the heat of incandescent hits the A/C load.

I was being very generous, I know, and allowing for a certain amount of exaggeration in stated equivalencies. Even then you'd probably come out ahead just leaving an LED burning, but there seems little point in doing so if you don't need to.

We have an LED in the dining room, which, with a dimmer, also serves as a night light. Given that it's something like 9 watts when full on, I presume, though I've never bothered to measure it, that it's less when dimmed than a conventional night light would be. But I still don't see any reason not to turn it off during the day.

 

[MikeG]

.....We have an LED in the dining room, which, with a dimmer, also serves as a night light. Given that it's something like 9 watts when full on, I presume, though I've never bothered to measure it, that it's less when dimmed than a conventional night light would be...........

Somebody will, I am sure, give us the full story on dimmers, but it may not be as you suggest. My sketchy understanding of them is that they use a good proportion of the electricity themselves, so that when the lights are dimmed what power doesn't go to the light fittings is absorbed by the dimmer and emitted as heat and noise (you have heard dimmers buzzing?). Thus offering no savings in power consumption at all. I may well be wrong.

 

[Delvo]

LED bulbs could allow pretty much the same effect as dimming by just not lighting up some of the individual LEDs at all. Turn it down and some dots go off; turn it up and some dots come back on.

 

[Jrrarglblarg]

Modern dimmers work by switching on and off, a form of pulse width modulation. That's why most CFLs don't work with them but LEDs do.

A reasonably useful explanation of dimmers:
http://home.howstuffworks.com/dimmer-switch3.htm

 

[bruto]

Somebody will, I am sure, give us the full story on dimmers, but it may not be as you suggest. My sketchy understanding of them is that they use a good proportion of the electricity themselves, so that when the lights are dimmed what power doesn't go to the light fittings is absorbed by the dimmer and emitted as heat and noise (you have heard dimmers buzzing?). Thus offering no savings in power consumption at all. I may well be wrong.

I believe you are wrong, in this case. Electronic dimmers operate by switching a solid state device which actually chops the electricity off intermittently. Of course there's a little power consumption and loss in the dimmer itself, but if it were as you suggest, it would be impossible to run, say, a several hundred watt incandescent fixture on a dimmer without burning holes in the wall.

 

[Jrrarglblarg]

A hundred watts of vibration and noise in the wall would be a sander. Scary thought.

LED lights are making their way into theatre applications as well. Like internal combustion, you can't beat incandescence for massive output yet so they're limited to smaller instruments, color wash for cyclorama lights and portable DJ rigs, plus you don't get a point source that can be focused with lenses. But I expect to see more and more of them replacing fresnel wash lights.

 

[paulhutch]

The original style of dimmer, (mostly pre-1975) was simply a high power rheostat (two terminal potentiometer) that reduced the voltage by turning it into heat. The old style dimmer system is specifically designed to accommodate the heat produced with no danger of fire. You can tell if a dimmer is old style by feeling the temperature difference between high power (cool) and low power (hot).

 

[MikeG]

The original style of dimmer, (mostly pre-1975) was simply a high power rheostat (two terminal potentiometer) that reduced the voltage by turning it into heat. The old style dimmer system is specifically designed to accommodate the heat produced with no danger of fire. You can tell if a dimmer is old style by feeling the temperature difference between high power (cool) and low power (hot).

This is what I had in mind when I made my comment previously. I was unaware that this technology has been superseded.

 

[bruto]

This is what I had in mind when I made my comment previously. I was unaware that this technology has been superseded.

Perhaps this differs from country to country. I do not recall when modern dimmers came into use here in the US, but we have had solid state (SCR or Triac) dimmers since the 1960's. I do not recall running into any rheostat dimmers for domestic use, although they were (and still may be) common enough for stage lighting and the like. Autotransformers (trade name Variac) turn up from time to time, but these do not simply turn excess voltage into heat either. They actually reduce voltage, and in the process reduce the load on the circuit. An autotransformer is actually a very nice way to dim a light, since it does not produce a chopped waveform, but it tends to be expensive and usually too large for a standard electrical box, and subject to mechanical wear.

 

[BenBurch]

There are LED bulbs coming that won't need dimmers because you'll be able to control them with bluetooth.

 

[PossumPie]

We need the technology of saving energy to LOOK attractive to people, then they see the benefit of buying into it. When you legislate 'good ideas' you cause resentment either b/c people don't like being forced to do something, or b/c unforseeable problems arise early on in a new technology. An example is one I gave a few pages back. The USA mandated the non-use of incandescent so the only early alternative was CFL lighting, I had to purchase them, they didn't work properly in a cold environment like my garage. Then LED lights came out and solved the problem. Why force me into a poor choice by law, THEN come up with an alternative. I think most people WANT to help the environment, they just resent being forced to do so by law. Just think about seat belt laws and NYC trying to make it illegal to sell a big soft drink...both save lives, but at what cost to freedom?

 

[MikeG]

I could hardly agree with you less, PossumPie. Oh, and as so often........sod your "freedom": it's just selfishness. You just want to be free to waste as much of the planet's resources as you can afford.

The biggest waster of energy in housing is the poor thermal performance of the building fabric itself, forcing the occupiers to pour large amounts of heat or coolth into the building to maintain a reasonably comfortable indoor environment. There are countless examples of zero-energy buildings which require neither heating nor cooling, in all sorts of climates, but they rely on large amounts of insulation, (generally) high levels of thermal mass, high performance glazing (such as triple glazing with inert gas and coated glass), and ventilation systems with heat recovery. They also require good design to take account of site aspect, to capture insolation when wanted but exclude it when it isn't wanted...........and so on. And if you have to put energy in to them, for space heating and hot water, there are some very low carbon ways of doing it, but they aren't cheap. This is my daily bread.

Now, you can carry on building cheap crappy buildings and pouring vast amounts of energy at them to make them habitable, or you can spend more and build buildings which don't require lots of energy to run. There are lots of examples of houses that are net energy exporters, (ie carbon-negative), and they can even work in cool, damp, cloudy places like Britain.

What is going to make people swap from building cheap, lightweight, crappy, energy-wasting homes and start building well designed modern low energy homes? What is going to force people to upgrade the existing housing stock to bring it closer to the standard of the best modern housing? I can't see market forces doing that, can you? Certainly not until it is way too late, anyway. No, the only way, in my view, that will ever happen is if Building Regulations, or whatever the local equivalents are, are tightened constantly, to require ever more stringent levels of energy efficiency in buildings.

It can be done. It is being done. It is happening here in Britain (Scotland has different rules, which I don't know an awful lot about). The house I am in I built 15 years ago, and it costs about £100 per year to heat. It used to be in the top 5 most energy efficient houses in the country. It wouldn't be in the top 100 now.

 

[macdoc]

You just want to be free to waste as much of the planet's resources as you can afford.

You have to be careful with that broad brush...there is no case that you are "wasting energy" if your source is wind, solar, nuclear, hydro, biomass

It may cost you more to make that choice to use more but you are "using something up" as you are with coal or other non- renewal.

I want an industrial society with all the conveniences and the wide choices that lots of available cost effective energy entails.....be flying acroos the world, taking a fishing trip, jot riding on motorcycle or car.

Right now tho - in too many areas that entails using up non-renewal AND polluting in the doing so.

But take a household in Sweden that wants to heat a little warmer. They pile on the wood pellets. Are they "wasteful???

Sun's gonna shine, rain's gonna fall, trees gonna grow and one more will be cut to serve their preferences.

Yes we can do better with efficient housing and cars especially when we depend on non-renewables and it does make sense financially.

The lowest hanging fruit to reduce fossil power needs is energy efficiency.

But some regions are not in that situation for homes and lighting and some are even getting beyond with vehicles.

That's where we all want to and keep adundance in mind - not sacrifice

 

[wobs]

You have to be careful with that broad brush...there is no case that you are "wasting energy" if your source is wind, solar, nuclear, hydro, biomass

Yes you are. Especially in a finite world. Whether they are renewable or carbon neutral or not is irrelevant. I'm suprised you made such a statement.

I want an industrial society with all the conveniences and the wide choices that lots of available cost effective energy entails.....be flying acroos the world, taking a fishing trip, jot riding on motorcycle or car.

Me too.

But take a household in Sweden that wants to heat a little warmer. They pile on the wood pellets. Are they "wasteful???

Yes.

The lowest hanging fruit to reduce fossil power needs is energy efficiency.

[cough]Jevons Paradox[/cough]
As I have already explained in the past.

Absolute energy consumption (regardless of source) is increasing. Below are some fun numbers to illustrate the issue:


Some interesting little numbers: Total Energy production in 2008 was 143851TWh (143.85*10^15) or 16.4TW every hour

Total energy hitting the Earth from the sun per year: 1524.24EWh (1524*10^18 ) or 174.0 PW (174*10^15) every hour

Total energy the sun produces every year: 3369096YWh (3369096*10^24), or 384.6 YW (384.6*10^24) every hour

Total output of the milkyway galaxy: 4.38*10^40Wh annually or 5*10^36W every hour

If global energy growth stays at 3% per year, then by the year 2794 our energy demands will exceed what hits the Earth from the sun

By 3985 it will exceed the total output of the sun. We would need a Dyson sphere or the surface of the Earth will be hotter than the surface of the sun. OK, this is a bit silly, but theoretically true.

By 4773 it will exceed the output of the milkyway galaxy!

The point is that economic growth equates to energy consumption growth (as I have shown you before). If we increase our consumption indefinately by a few % each year, the Earth will still fry even if we use 100% renewables.

 

[MikeG]

You have to be careful with that broad brush...there is no case that you are "wasting energy" if your source is wind, solar, nuclear, hydro, biomass........

Yes, fair point, well made. However, it isn't quite as straight forward as that.

If you waste renewables, you make less of them available to those who don't have such access to renewables, and who are burning fossil fuels. That is most of the population of the developed world at the moment. Given that renewable sources of electricity are relatively scarce at the moment it strikes me as obvious that a country with plenty of spare capacity because of, say, lots of hydro-electric resources, has the chance to export that spare capacity to a neighbour, thus reducing the neighbour's reliance on fossil fuel. But only if they haven't squandered the resource by expanding demand to meet supply within their own borders.

 

[wobs]

While I'm having fun with numbers, just a reminder that the theoretical limit for lights is 350 lm/W.

Many modern LEDs are in the order of 100lm/w, but the best a quick search can find is 275lm/w.

What this means is that if/when we get to 350, that's about as good as it will get for any lighting technology, and the only way to save energy further is turning it off.