I can’t believe this degenerated into an argument about types of lighting.

the current mix of filament, neon, halogen, and high/low pressure sodium

Er.. filament street lights? Neon street lights? You what?

Does anyone else apart from Aracer have trouble with the SI definition of the lumen?

Does anyone apart from Aracer think the lumen is defined in terms of the electrical potential in the optical nerve? If you do, how do you think lights are tested?

Does anyone apart from Aracer have trouble with the idea that the colour of a light influences the way it illuminates things and how humans percieve the objects being illuminated, both objectively and subjectively. And that a white light source with the same number of lumens as a yellow light source will better illuminate anything other than a completely yellow object because other colours will absorb the yellow light?

Does anybody apart from Edu not understand that the SI definition of the lumen is based upon the eye’s response to light?

Does anybody apart from Edu not understand that the SI definition of the lumen is based upon the eye’s response to light?

Given it’s only yourself and Edukator who are engaged in this spat, it may be that no one else sees it as pertinent to a discussion about how to store the excess energy generated by windfarms?

So, there’s a nice strong storm in the middle of the night. It gives up just before dawn. The nation’s hot water tanks cool down just before everyone gets out of bed to have a shower, and all they get is cold water poured on them.

The immersion heater we had removed from our house only 2 years ago could keep hot water at a useable temperature for at least 12-14 hours. So while I have some reservations about how cost effective it would be to implement this system in a country with such a high preponderance of combi boilers and gas central heating, I don’t think retaining hot water at a useful temperature would be one of the problems.

Never walked through a town centre, Molgrips? Have a walk through your local town tonight and you’ll find all of those types of lighting in use in both public and private installations. Local advertising billboards have neon strip lights in them (there could be a cultural problem here – “neon” in French refers to the classic 36W strip light), shop signs have neon-neon lights if you see what I mean. Surely you ‘ve seen neon-strip street lights, I remember them in Brum in the 60s and I bet they are still used. Halogen illuminates facades. There are lights everywhere and not all are sodium.

Have you climbed your lampost yet? The one outside my house is made by 3e International and can be delivered with sodium bulbs between 35W and 250W. It’s brand new and hopefully a 150W low-pressure sodium, but I’d have to climb up it to be sure. I’d be much happier if they’d installed a white 60W LED light.

In my local town I noticed a few LED lights recently. Filament bulbed traffic lights are thankfully being repleced with more reliable and economical LED lights and I’ve also noticed a few LED street lights in architectural applications in flash hotels and so on where image is important and the cost of LED lights acceptable.

Local advertising billboards have neon strip lights in them

And those are not street lights.

“originally based on” but not “defined in terms of”, Aracer. The horsepower was origianlly based on the power of a horse but defined in terms of watts (or joules and seconds if you prefer).

Just as Aracer spent days attacking my statement that “there is enough hydro electricity in Europe for my level of electricity consumption even in December” Aracer has chosen to pick on one small point in one of my posts and spend hours attacking me by deliberately misinterpreting what I originally said.

“originally based on” but not “defined in terms of”

Are you being ridiculously pedantic, or do you just not get it (either seems plausible)? Have you actually bothered reading and comprehending all those Wiki articles you use as reference – I mean even the French language ones mention the response of the eye. I’ll pick some bits out to try and help:
“1 lm = 1 cd·sr” – so the definition of the lumen is based on the definition of the candela – I think we both agree on that?
“The candela is the SI base unit of luminous intensity; that is, power emitted by a light source in a particular direction, weighted by the luminosity function (a standardized model of the sensitivity of the human eye to different wavelengths)”
“Like other SI base units, the candela has an operational definition—it is defined by a description of a physical process that will produce one candela of luminous intensity” – that’s the one you quoted before which describes how to calibrate an instrument. The thing is, given the operational definition only mentions one frequency how do you think you measure the brightness of a different frequency.

Just as I gave up on the previous point due to your unwillingness to accept usage of electricity outside the domestic environment, I’m probably going to give up on this one due to your inability to read and comprehend wiki articles. Apologies to everybody else on here – the problem is clearly your complete unwillingness to ever admit to being wrong, even when the point under discussion is quite obviously outside your area of expertise, but something the person you’re arguing with has actually studied.

So as to avoid misinterpretation, lets just requote what you originally said:

LED street lights illuminate better and consume less than a third compared with sodium

I’d suggest that LED lights actually being less efficient at converting electricity into visible light is quite a fundamental point given that assertion.

Of course if you’re willing to admit that “The definition of the lumen is based on light energy on a surface not the electrical signal generated by the retina and sent to the brain” is wrong, then maybe we can put a little bit of this to bed. Or am I misinterpreting you again?

Just in case it helps in the least little bit

how do you think lights are tested?

Using an integrating sphere is the standard method (at least for measuring total lumen output). This utilises a meter with the standard luminosity function used for weighting of different frequencies in the spectrum, such that the output is a direct measure of the brightness perceived by the human eye.

Are you being ridiculously pedantic

It seems to be his entire raison d’etre….

Use some multi-layer insulation to make a jacket for your hot water tank ditch-jockey. I did so when I found my solar tank was getting warm to the touch and it’s increased the time water stays warm from the 12-14 hours you mention to at least 24 hours. It’s increased the period we don’t need the immersion heater by a few weeks.

You’re failing again, Aracer. You seem to have forgotten is was you that got picky/pedantic and rubbished my original comment on LED lights, refusing to accept that the colour of light is important in how it illuminates and is perceived by humans. You were the one that raised the question of lumens but refuse to accept that a human will not perceive a lumen of yellow light shone on a multi-coloured street as being as bright as a lumen of white light due to absorbtion of the yellow light by many colours. The SI definition of the lumen I used is fine.

On the previous point my level of electricity consumption leaves plenty left over for industry and infrastructure on the basis they make equivilant reductions in consumption. Should anyone wish to do the calculation I’ll remind you that as a family of three our net electricity consumption for the month of December was 130kWh. That’s 1.4kWh per person per day which dividing by 24h is on average 58W per person being drawn from the grid. Multiply that by a population of 300 million and Europe would need an average installed capacity of 18 GW to meet domestic demand in the coldest, darkest month. Now remind me of the figure you yourself gave for the current installed hydro capacity in Europe, several hundred GW right?

You persist in acusing me of lying or being wrong, Aracer, I just keep providing evidence I’m right.

Ha, zokes is here now too. Where’s Zulu or Graham the nuke fan?

STW’s great, innit!

You seem to have forgotten is was you that got picky/pedantic and rubbished my original comment on LED lights

Well if pointing out your “evidence” comes from a biased site and is clearly inaccurate and flawed is picky/pedantic, guilty as charged m’lud.

refuse to accept that a human will not perceive a lumen of yellow light shone on a multi-coloured street as being as bright as a lumen of white light due to absorbtion of the yellow light by many colours

I’ve not even got onto that yet – still waiting for you to accept that the lumen is a measure of brightness as perceived by the human eye. Given you’ve now wiggled your way round to that as your sole point I haven’t shot down (from what I can work out your argument was based on that dodgy article and you originally thought LEDs gave more lumens), I guess I should address it though – we’ll start with a few points and work from there:
1) a significant range of colours will actually look brighter under yellow than white – lots of the power of white light is also absorbed by coloured surfaces.
2) do you know what the spectrum of a “white” LED looks like, and that a significant amount of its power is concentrated in a narrow spike, hence point 1 applies even more so?
3) given the lumen advantage for sodium over LED, you’d have to have twice the reflection of the “white” LED spectrum to get any advantage in terms of perceived brightness of a surface.
4) this whole argument is based upon handwaving and the evidence of a single extremely dubious and quite clearly biased article. Give me something where the photographic evidence is at least from the same viewpoint and has the same manual exposure setting (I’m assuming peer reviewed is too much to ask?), and we might have something worth discussing.

Use some multi-layer insulation to make a jacket for your hot water tank ditch-jockey.

That would be the hot water tank I mentioned removing 2 years ago in favour of a combi boiler and a wood burner! Fortunately, all this newly discovered shale gas will keep the combi going for my lifetime, and the wood burner lets me tick the ‘renewables’ box as well, plus I get lots of exercise from collecting the wood, sawing it and chopping it up ready for seasoning.

Once you get the shale gas, you won’t even need the combi boiler to heat the water 🙂
[video]http://www.youtube.com/watch?v=aAWuTmJPH2o[/video]

plenty left over for industry and infrastructure on the basis they make equivilant reductions in consumption

You keep failing to appreciate that such reductions are a pretty big assumption, given the huge differences in energy usage to domestic.

our net electricity consumption for the month of December was 130kWh. That’s 1.4kWh per person per day which dividing by 24h is on average 58W per person being drawn from the grid

There’s another couple of your flaws – you’re not only assuming everybody is also generating like you (do we really have to rehash why that’s just not possible for everybody?), but assuming you only need to supply average, not peak (the times when you’re generating and asleep in bed using no power might help the average, but don’t do much for the peak).

I just keep providing evidence I’m right.

I suppose it depends what you mean by “evidence”. I really cba arguing about this energy utopia of yours any more, so you can carry on thinking that if you like.

On led street lamps, the one outside my parents house has just been changed from a yellow sodium? lamp to an led, and the new light is massively brighter, they really need new thicker curtains in their front bedroom – it lights the whole room if the curtains are open. I assume they wouldn’t swap for a higher wattage, so I guess leds are brighter.

8)

It’s threads like this that make me wonder if it is actually true.

You know. As in that documentary.

About how the machines, having taken over, are now deriving all their energy from the heat and electricity given off by our imprisoned bodies.

I bet they love threads like this. Do machines have immersion heaters?

Ha, zokes is here now too. Where’s Zulu or Graham the nuke fan

I was here all the way back up there^^^ In fact, I insinuated that the thread might be a bit longer, if a lot less worthwhile, if you and TJ joined in. I was clearly correct.