Light pollution: an environmental fad?

The Times (of London) is asking its readers: Is Light Pollution just
another environmental fad?
Please, keep your contributions short and to the point and send them
to :
quoting their article on the Tuesday October 7 edition where their
science correspondent Mark Henderson considers the report of the
Inquiry on'Light Pollution and Astronomy' compiled by the Science and
Technology Select Committee of the House of Commons, UK Parliament.

This report can be accessed at:
http://www.publications.parliament.uk/pa/cm200203/cmselect/cmsctech/747/74702.htm

Pierre

"Pierre" ha scritto nel messaggio
om...
The Times (of London) is asking its readers: Is Light Pollution just
another environmental fad?
Please, keep your contributions short and to the point and send them
to :
quoting their article on the Tuesday October 7 edition where their
science correspondent Mark Henderson considers the report of the
Inquiry on'Light Pollution and Astronomy' compiled by the Science and
Technology Select Committee of the House of Commons, UK Parliament.

This report can be accessed at:

http://www.publications.parliament.u...sctech/747/747
02.htm

Pierre

Go on our webpages http://www.cielobuio.org and pick some pictures from the
gallery Mostri del cielo (Sky monsters).

Clean and dark skies,

--
Beta Persei
45° 35' N
08° 51' E

"Elysium Fossa" wrote in
:

Most of the light from street lights go into the sky, rather than
lighting the streets, its like trying to heat you home in winter with
all the doors and windows open , a terrible waste of
energy......hardly an environmental fad. But I wouldn't take much
notice of anything in the Times.

I don't know about "most" of if, but a significant percentage of it does.
Bryan

In message , PrisNo6
writes
This was really an enjoyable legislative committee report looking at
light pollution. I wish we had something like this in
America.

I suspect that you do, but it is mostly on a state by state basis rather
than by a national policy group. Zion canyon, Utah has some of the best
sky friendly lighting that I have ever seen. And professional US optical
observatories are also better served and protected by your lawmakers.

Buried in one of the sections was a reference to the British
Astronomical Association's testimony before the commission that just
the governmental controlled highway lights in England emit .33
gigawatts (333 megawatts) straight up into the sky

But it is a bit worrying in a report from a scientific committee that
the units of measurement are inconsistent. The phrase actually said
"wasted light ... from street lights amounts to 0.33 of a gigawatt a
year". (Sic.)

It is unclear from this statement whether they mean a continuous loss of
0.33 GW during the hours of darkness or a total loss of 0.33GJ in a
year. There is a big difference between these two interpretations. A
back of the envelope calculation suggests it is the former. That is a
lot of wasted light!

I found the lack of background quantitative data in the main report
rather disheartening. It is so easy to latch onto the emotive issue that
orange skies are bad, blame LPS lights and miss the wider picture.

We actually need to get full cut off (FCO) shields retro fitted into
existing low pressure sodium (LPS) units rather than have a wholesale
replacement bean feast for the lighting industry. They are the only real
winners if the report is adopted as it stands.

The sop to astronomers is that they might just cut light pollution by
about 20% which translates to about 0.2 visual magnitudes improvement in
sky brightness. The downside is that HPS light is broadband and cannot
be filtered out. We will have opted for perpetual artificial white
moonlight.

The light pollution committee sided with industry and concluded that it
might not be possible to save any energy by upgrading the
government highway lights (I could not figure why),

Probably because the installed base of LPS lights are roughly 2x more
energy efficient than the HPS lights that will replace them. HPS even in
FCO fittings cannot make up for the intrinsically much higher luminous
efficiency of the older lamps. Unfortunately LPS lamps are typically in
very badly designed old luminaires and put up to 30% of their output
straight up!

Despite what the ILE in the UK says there is no reason why FCO
luminaires for LPS lamps cannot be manufactured. They are used for
street lighting in mainland Europe. And then you do get energy savings.

The Times topic was titled "Light pollution: an environmental fad?"

Certainly a loaded question but the article that contained this was more
balanced than this single isolated phrase might suggest. I will wait to
see what contributions to that debate are actually published.

Maybe the debate title should be "Wasting our grandchildren's
non-renewable resouces: fad or unrestrained gluttony?"

I would suggest for a question loaded the other way:
"Gratuitous waste and excessive consumption as a fashion statement?"

Regards,
--
Martin Brown

Martin Brown wrote in message ...
In message , PrisNo6
writes snip

Thanks, Martin. Your informed comments gave me many insights into an
area I do not know much about.

Despite what the ILE in the UK says there is no reason why FCO
luminaires for LPS lamps cannot be manufactured. They are used for
street lighting in mainland Europe. And then you do get energy savings.

My own impression in the U.S. is that politically the only way that
light-pollution reduction could be "sold" to the non-astronomy public
is on the grounds of increased energy efficiency. This assumes that
the life-time replacement and electricty costs of FCO-LPS lamps for
highway lighting is less than life-time costs of new lamps as existing
ones wear out.

My own impression in the U.S. is that
politically the only way that
light-pollution reduction could be "sold"
to the non-astronomy public is on the
grounds of increased energy efficiency.

I'm a little encouraged as of late. For the first time since the
disastrous explosion of mercury vapor lighting back in the sixties, I've
noticed some awareness of intelligent lighting, as opposed to blatant
QUANTITY of light. My little burg here in Iowa recently replaced the
streetlights on the highway going through town, and replaced the old
cobra head fixtures with very well shielded lights. (with no pressure
from me, as I didn't know they were going to do it until the fixtures
were bought and paid for.) Not long ago, no one in charge here would
have even known that such fixtures existed. As the public sees the
improvement in visibility, I feel an awareness will grow. I've sure
been pointing it out to people!
Marty

In message , PrisNo6
writes
Martin Brown wrote in message
...
In message , PrisNo6
writes snip

Despite what the ILE in the UK says there is no reason why FCO
luminaires for LPS lamps cannot be manufactured. They are used for
street lighting in mainland Europe. And then you do get energy savings.

My own impression in the U.S. is that politically the only way that
light-pollution reduction could be "sold" to the non-astronomy public
is on the grounds of increased energy efficiency.

The US installed base being mostly mercury lights would tip the balance
in favour of replacement. An HPS lamp is 2x and LPS lamp 4x more energy
efficient. Either would make a significant contribution to energy
saving.

Couple that with the EPA environmental requirement to phase out non
essential use of mercury and you have a pretty good case.

This assumes that
the life-time replacement and electricty costs of FCO-LPS lamps for
highway lighting is less than life-time costs of new lamps as existing
ones wear out.

The MTBF for the lamps are different (HPS 30000h, LPS or mercury 20000h)
.. So the critical thing becomes whether the lifetime energy savings
outweigh the cost of changing the bulbs every 2 instead of 3 years. How
much you pay the guy to change a light bulb is the key...

In the UK at the moment we have a rather large ageing population of
street lamps due for renewal. Highways agency is actually doing a fairly
good job too. Most of the new replacements in sensitive rural areas are
full cut off shielded now - definitely an improvement.

Unfortunately the new HPS lamps in my village are only pseudo full
cutoff. The lamp itself is shielded but a vast plastic bubble fresnel
lens hangs down and scatters lots of light everywhere.

Regards,
--
Martin Brown

My own impression in the U.S. is that politically the only way that
light-pollution reduction could be "sold" to the non-astronomy public
is on the grounds of increased energy efficiency. This assumes that
the life-time replacement and electricty costs of FCO-LPS lamps for
highway lighting is less than life-time costs of new lamps as existing
ones wear out.

The other route is an more attractive town. Shielded lighting is more
attractive than unshielded lights. That's why some communities have passed
light-pollution ordinances. It increases property values.

A landscape architect friend is amazed that many people just don't realize
how effective lighting can make a place more attractive. BTW He doesn't
care about light pollution and is rather paranoid about safety.

Vladimir