On Sun, 27 Sep 2009 17:06:33 GMT, Zero Tolerance wrote:

Osram 15w (75w equiv) - 900 lumens
Philips 20w (100w equiv) - 1200 lumens

Bloggs 60W (60W equivalent - i. e. a filament bulb) - ? lumens?

Somewhere between 700-900 lumens, according to the first page of a
(not necessarily particularly scientific) google search.

The ones that have a figure(*) in our cupboard are 700 or 710 lumens.
When I was looking in a shop the other day they where also around 700
lumens.

One has to be careful these days with the halogen capsules that are
contained in a traditionally shaped envelope. A 60W one of they would
more light than a 60W normal tungsten filament bulb.

(*) Some are so old they don't have the energy efficiency chart on
let alone proper figures on their performance. We just don't use
tungsten bulbs any more.
--
Cheers
Dave.

On Sun, 27 Sep 2009 16:33:02 +0000, Richard Tobin wrote:

In the standard model, protons don't decay.

Is Wikipedia correct in its assertion that

QUOTE
Proton decay has not been observed.
There is currently no evidence that proton decay occurs.
UNQUOTE

On Sun, 27 Sep 2009 19:04:25 +0100, Bill Wright wrote:

That's why they weigh more.

Yes and possibly they are a little slower than others, since rates of
reactions for molecules with atoms of heavier isotopes are very slightly
slower.

This effect is best observed with heavy water, since the difference in
mass of the hydrogen is double, and why it is toxic and drinking heavy
water is not a good idea.

http://www.straightdope.COM/columns/read/2135/is-heavy-water-dangerous

Java Jive wrote:
On Sun, 27 Sep 2009 06:10:31 +0100, The Natural Philosopher
wrote:

Java Jive wrote:

almost as high as 3%.

I confess I've heard *widely* varying estimates of this, but this
seems to agree with you:

http://en.wikipedia.org/wiki/Nationa...28UK%29#Losses

"Although losses in the national grid are low, there are significant
further losses in onward electricity distribution to the consumer,
causing a total distribution loss of about 7.7%.[6] However losses
differ significantly for customers connected at different voltages;
connected at high voltage the total losses are about 2.6%, at medium
voltage 6.4% and at low voltage 12.2%"

Of course, most of us are at the low voltaage/high loss end, but, as
that's a local loss, I guess that would probably apply to all sources
except micro-sources at each home.

All forms of renewable energy will lead to higher transmission losses.
Pumped storage is at best 70-80% efficient.

Last time I looked, nuclear, gas, and coal were only around 30%
efficient at turning steam into electricity.


45-55%.

2) Relatively few large scale technologies are used, making them
difficult to replace with alternatives.

That's as specious as saying that its a shame we can only breathe air,
and not water.

That's a completely irrational non-sequitor. We don't have biological
mechanisms that dictate how we must convert resources into
electricity, like we do dictating how we breathe.

We dont NEED any alternatives if what we have works very well.

But it won't, see my other post.


Completely refuted.

3) The frequency and voltage of supply need to be kept within
expensively tight tolerances to avoid things breaking down.
They don't actually. Not from a generating point of view. Its the
consumers whose lightbulbs would pop and whose clocks would run slow
that first caused teh whiole thing to be stabilised.

That was what I meant.

4) Cheap energy has encouraged waste.
Nothing encourages waste, but why not? cheapness is a mark of something
that doesn't need to be a huge concern.

If it's not a huge concern, then why is everyone except yourself very
concerned about it? That should tell you something.


If its so expensive, why are you still using it? that should tell you
something.

Energy is NOT expensive. Its bloody CHEAP. Except windpower which is
subsidised to MAKE it cheap.

I am concerned because it wont stay that way much longer. Fortunately
nuclear power is competitive at current ,market rates of oil and gas, so
the economic incentives PROVIDED the investors are sure that they are
NOT going to be shut down at a political whim, are very attractive.




Cheap energy has also meant
that twits like you can live a life of luxury and comfort that your
grandparents could only dream of, and have time to write this crap online.

Bah! Pots and kettles!


You have no idea how frugal I am.

1) Transmission losses could be much lower.
No, we couldn't.
If we built more stations, it costs more, uses more materials, and uses
more fuel. BIG stations with condensers stuck on e.g. rivers are more
efficient than a small onea. There are significant economies of scale.
both in cost, materials used and actual output efficiencies.

Considerations which apply most strongly to fossil-fuel sources in
centralised systems.


Which is why they are better more efficient and cheaper than localised
generation. Or windmills.


2) A greater range of generating technologies could be used.
The generating technology of a windmill is the same as a power station
anyway, its juts 3-6 times more iron and copper to achieve the samme result.

That's serious, it's true, but must be viewed as an investment in
reducing CO2 emissions overall.

3) Equipment could be more tolerant to fluctuations in supply.
Modern electronic power supplies are, anyway.

My experience suggests that there is no difference between the
reliability of moderrn PSUs and those of, say 20 years ago. Far too
many of them failed and still fail.


Er.. that is a complete non sequitur.
An SMPS capable of working from 40v to 400v is possible. IT doesn't help
however, because to do the same job it simply pulls the same power out
anyway. If that power isn't going in, then reducing voltage to shed load
doesn't work. You end up not with brownoiuts, but blackouts.

Whether its reliable or not has nothing to do with it.


4) Energy could be used more efficiently.
Yes, but that has nothing to do with how its generated.

But does very much affect the amount we need to generate.


WE are already very efficient with energy use especially electrical
energy use. Very little is wasted to do a job that its not supposed to
do. I.e. an electrical heater is 100% efficient, electric motors are in
the 70-97% sort of range, electric LIGHTS are up around 15% for the most
efficient, and we don't use a vast amount of that electricity that way.

Energy is not being wasted in industrial processes., Its if anything
being wasted by people buying more stuff than they need, its true, but
you be the government that tells them they can only eat certain things,
only buy one mobile phone every ten years, only leave the house one day
a week, and then only by certified public transport. etc etc.



... from which, although this isn't one of the ones I remember
hearing about previously, it'll certainly do:

http://www.windandsun.co.uk/Projects/eigg.htm

Its utter bull****

Where is your evidence for this assertion?

and I bet it was funded by EU grants.

Most early nuclear work was similarly funded by subsidies and grants
from one source or another.


So was all wind work.

But no new nuclear is being subsidised.

Not true of windmills.

In message o.uk, Dave
Liquorice writes
On Wed, 23 Sep 2009 22:57:12 +0100, Paul Martin wrote:

If you start with a finite number of radioactive atoms you'll
halve the
number every half-life period

On average. Sometimes it will, sometimes it won't. It's random.

, at some point there'll be one atom left and when that decays it's
all gone.

On average. Maybe. It's random.

Quite. If the half life is say 1 year after 1 year there is a 50%
*probabilty* that the lone atom might have decayed. Even after
hundreds of years you can't say that that lone atom *will* have
decayed just that the probabilty of it happening is pretty high(*)
but you can't say when it will happen.

IIRC the original assertion was that the radiation would never fall to
zero. If there's just one atom left and it doesn't decay then it
releases no radiation. Once that last atom has decayed there's also no
radiation.



--
bof at bof dot me dot uk

Java Jive wrote:
Ok, it was a good few years ago when I last looked. Source? Numbers?


Top posting. crap sig file. Who is this dickhead?

Anyway its standard knowledge. Overall thermal efficiencies of most
steam plant has been around 45% or more from at least the 60's onwards.

Java Jive wrote:
On Sun, 27 Sep 2009 06:41:34 +0100, The Natural Philosopher
wrote
SOME. Not all. David is as guilty here as those he points out elsewhere
who mix their facts to get the desired effect.

Source for this information?

Now we see the fundamental hypocrisy
in your position. Windpower it seems DOES need long lossy lines after
all, when you claimed in your last post that this was one of its
advantages, Local generation.

No, I claimed in my last post that the grid system was too
centralised, whereas it would be more useful in our present concern
for it to be more decentralised.

There is nothing centralised about the grid.

It is the least centralised electricity network in the world, probably.


Once again you are arguing from assumptions that are complete and utter
hogwash.

Even my house, is on an 11KV *ring* Not a spur, a RING.
..




On a level UK playing field, we have plenty of wind and rain, some
sun, and no uranium ore.


WE have totally inadequate wind rain and places to generate hydro pwer.


The field is tilted way against nuclear and way pro wind, that's all.

Whereas historically it has been the other way about.

It has not.

Ever.

Java Jive wrote:
Absolutely, just as we would have to look at our hydro potential in
tandem with our wind potential.

we have almost no hydro potential whatsoever.

Since it is if the geography is right, one of THE cheapest ways to
generate power, every hydro site that makes sense already HAS a power
station.

J G Miller wrote:
On Sun, 27 Sep 2009 09:43:55 +0100, Jim Lesurf wrote:

The reality is that we are surrounded with large amounts of materials
with very long half lives. Including our own bodies.

Apparently people born in the 1950s have a higher level of carbon-14
in their bodies than the rest of the population.


hasn't killed us yet has it?

J. P. Gilliver (John) wrote:
In message ,
Bambleweeny57 writes:
[]
Yes, we already have backup capacity but its already "spoken for" by a
combination of variations in load and redundant capacity to cover for
maintenance and failure. Shaving a few points off that backup capacity
just increases the scope for large scale, systematic failure.
[]
If it never represents a significant percentage of the whole it's only
ever going to be a distraction from the real issue of how we cater for
our energy need for the next 50 years.

I guess we're going to have to agree to disagree, on the earlier area: I
think a small amount is worth having, and because it _is_ such a smaller
amount, the threat it poses to the stability of the rest is small -
it'll just mean the rest of the system will use slightly less fuel for
some of the time.


why should I subsidise a horse and cart, so that it is there if the car
breaks down?


On the second point, we are definitely in agreement: since there's no
way wind is going to contribute more than a few per cent, we definitely
have to give our attention to where the rest is going to come from. (As
I see it, in the medium term - the rest of my lifetime, roughly - for
this country, nuclear is going to be at least a significant part. That
and carbon-based sources!) As for wind, it might be a distraction, but
conversely it might also help concentrate people's mind on the problem:
most people are not thinking about it enough (or at all in most cases).
There's no real way to know.

(And, strangely, the perfectly valid point that backup capacity
has to be available is _helped_ by the smallness of the proportion: you
_won't_ have _lots_ of capacity sitting idle, since the wind isn't going
to provide a _lot_ of the capacity anyway, unlike say in Denmark.)

Denmark uses about 20% wind generation capacity in "in country" power.
However, it is connected to the continental European grid so it has
access to a massive source/sink to counter the variability of wind.
[]
Another poster has said that, however, they have scaled back their
alternative capacity to the point where they _have_ to import (and just
_hope_ there is someone to sell to them) when it's not windy enough.
Whether this is so, I don't know.

charles wrote:

No it really happened - but the story only briefly mentions the "back up
diesel generation".


Umm yes: "Various renewable sources distributed around the island have
been incorporated to allow diversity of energy supply, - a 9.9kWp PV
system, three hydro generation systems (6 kW, 6 kW & 100 kW) and a 24
kW wind farm supported by standby diesel generation and batteries to
guarantee continuous availability of power."

To me that reads as a system with 112kW of hydro and 34kW of everything
else put together.

I have no problem with Hydro, except there is a lack of sites. Even
with 30% of "other" they have to have batteries and backup diesel;
hardly practical for an entire nation, even if it's fine for 87 people
on a small island.

Wind is OK up to a point; but it's a small point.

Andy

The Natural Philosopher wrote:
J G Miller wrote:
On Sun, 27 Sep 2009 09:43:55 +0100, Jim Lesurf wrote:

The reality is that we are surrounded with large amounts of
materials with very long half lives. Including our own bodies.

Apparently people born in the 1950s have a higher level of carbon-14
in their bodies than the rest of the population.


hasn't killed us yet has it?

Not those who are still alive, no.

In article ,
Andy Champ wrote:
charles wrote:

No it really happened - but the story only briefly mentions the "back up
diesel generation".


Umm yes: "Various renewable sources distributed around the island have
been incorporated to allow diversity of energy supply, - a 9.9kWp PV
system, three hydro generation systems (6 kW, 6 kW & 100 kW) and a 24
kW wind farm supported by standby diesel generation and batteries to
guarantee continuous availability of power."

I ssupect that last "100kW" is morelikely to be 10kW. There isn't that much
water available.


To me that reads as a system with 112kW of hydro and 34kW of everything
else put together.

I have no problem with Hydro, except there is a lack of sites. Even
with 30% of "other" they have to have batteries and backup diesel;
hardly practical for an entire nation, even if it's fine for 87 people
on a small island.

Wind is OK up to a point; but it's a small point.

Andy

--
From KT24

Using a RISC OS computer running v5.11

On Sun, 27 Sep 2009 21:31:57 +0100, The Natural Philosopher wrote:
WE have totally inadequate wind rain and places to generate hydro pwer.

Then why did there used to be a power utility called The North of
Scotland Hydro-Electric Board which generated and distributed electrical
energy to Northern Scotland?

http://en.wikipedia.ORG/wiki/North_of_Scotland_Hydro-Electric_Board

"J G Miller" wrote in message
news
On Sun, 27 Sep 2009 21:31:57 +0100, The Natural Philosopher wrote:
WE have totally inadequate wind rain and places to generate hydro pwer.

Then why did there used to be a power utility called The North of
Scotland Hydro-Electric Board which generated and distributed electrical
energy to Northern Scotland?

We have hydro plants on streams that can generate a couple kilowatts, it
doesn't mean we can supply the whole country with clean power. They are just
inadequate for the job.

In article , dennis@home
wrote:


"J G Miller" wrote in message
news
On Sun, 27 Sep 2009 21:31:57 +0100, The Natural Philosopher wrote:
WE have totally inadequate wind rain and places to generate hydro pwer.

Then why did there used to be a power utility called The North of
Scotland Hydro-Electric Board which generated and distributed
electrical energy to Northern Scotland?

We have hydro plants on streams that can generate a couple kilowatts, it
doesn't mean we can supply the whole country with clean power. They are
just inadequate for the job.

The above organisation, in its current guise of Scottish & Southern Energy,
has just commissioned a new 100MW hydro scheme at Glendoe and hopes to turn
the existing Sloy scheme (at 153MW - the biggest in the country) into a
pumped storage one. so much for "streams generating a couple of kilowatts"

--
From KT24

Using a RISC OS computer running v5.11

"charles" wrote in message
...
In article , dennis@home
wrote:


"J G Miller" wrote in message
news
On Sun, 27 Sep 2009 21:31:57 +0100, The Natural Philosopher wrote:
WE have totally inadequate wind rain and places to generate hydro
pwer.

Then why did there used to be a power utility called The North of
Scotland Hydro-Electric Board which generated and distributed
electrical energy to Northern Scotland?

We have hydro plants on streams that can generate a couple kilowatts, it
doesn't mean we can supply the whole country with clean power. They are
just inadequate for the job.

The above organisation, in its current guise of Scottish & Southern
Energy,
has just commissioned a new 100MW hydro scheme at Glendoe and hopes to
turn
the existing Sloy scheme (at 153MW - the biggest in the country) into a
pumped storage one. so much for "streams generating a couple of
kilowatts"


You can not supply enough hydro electric power in the UK for it to solve our
energy problems.
It is inadequate even if you dam every valley.

Rest assured, Goldman Sachs (GS) is determined to make sure that
energy of any form is no longer "cheap".

The same goes for food (agriculture) as they, plus carbon, are the new
super-commodity markets with super-distortions. Enron showed just how
much money could be extracted.

It will be a case of energy prices rise to negate technological
improvements, since energy will be a prime source of taxation in the
anglo-america and much of the world. All disguised as "green" of
course, a repeat of the UFO groups.

On Sun, 27 Sep 2009 22:26:11 +0100, dennis@home wrote:

We have hydro plants on streams that can generate a couple kilowatts

Sounds like Scottish Power generate more than a *couple of kilowatts* to me
from hydro electric schemes --

Lanark Hydro Electric Scheme 17 MW

Galloway Hydro Electric Scheme 106.5 MW

On Sun, 27 Sep 2009 23:06:32 +0100, dennis@home wrote:

You can not supply enough hydro electric power in the UK for it to solve
our energy problems.

Nobody has claimed that hydro electric power generation *alone* can provide
the total electrical energy requirements of the UKofGB&NI.

In article ,
J G Miller wrote:

Is Wikipedia correct in its assertion that

QUOTE
Proton decay has not been observed.
There is currently no evidence that proton decay occurs.
UNQUOTE

As far as I am aware that's correct, but I'm not a physicist.

AIUI, many physicists believe that they do decay, because they
believe a certain kind of unified theory must be true, and such
a theory would imply it. But that's an intuition about what
must be true, rather than something backed by physical evidence.

-- Richard

--
Please remember to mention me / in tapes you leave behind.

"J G Miller" wrote in message
news
On Sun, 27 Sep 2009 19:04:25 +0100, Bill Wright wrote:

That's why they weigh more.

Yes and possibly they are a little slower than others, since rates of
reactions for molecules with atoms of heavier isotopes are very slightly
slower.

This effect is best observed with heavy water, since the difference in
mass of the hydrogen is double, and why it is toxic and drinking heavy
water is not a good idea.

So you'd advise me to cut our the heavy drinking?

Bill

"Paul Martin" wrote in message
...
In article ,
Of course, it does nothing to relieve the world of 500W halogen yard
search lights.
What's the alternative?

Bill

"Bill Wright" wrote in message
...

"J G Miller" wrote in message
news
On Sun, 27 Sep 2009 19:04:25 +0100, Bill Wright wrote:

That's why they weigh more.

Yes and possibly they are a little slower than others, since rates of
reactions for molecules with atoms of heavier isotopes are very slightly
slower.

This effect is best observed with heavy water, since the difference in
mass of the hydrogen is double, and why it is toxic and drinking heavy
water is not a good idea.

So you'd advise me to cut our the heavy drinking?

That's funny. My typing is a bit slurred. Mush go bed.

Bill

In article , dennis@home
wrote:


"charles" wrote in message
...
In article , dennis@home
wrote:


"J G Miller" wrote in message
news On Sun, 27 Sep 2009 21:31:57 +0100, The Natural Philosopher wrote:
WE have totally inadequate wind rain and places to generate hydro
pwer.

Then why did there used to be a power utility called The North of
Scotland Hydro-Electric Board which generated and distributed
electrical energy to Northern Scotland?

We have hydro plants on streams that can generate a couple kilowatts,
it doesn't mean we can supply the whole country with clean power. They
are just inadequate for the job.

The above organisation, in its current guise of Scottish & Southern
Energy, has just commissioned a new 100MW hydro scheme at Glendoe and
hopes to turn the existing Sloy scheme (at 153MW - the biggest in the
country) into a pumped storage one. so much for "streams generating a
couple of kilowatts"


You can not supply enough hydro electric power in the UK for it to solve
our energy problems. It is inadequate even if you dam every valley.

whoever suggested you could? However, it does make a significant
contribution to the UK's energy pool. Scotland creates more than it uses
and exports the surplus to England.

--
From KT24

Using a RISC OS computer running v5.11

John Rumm wrote:
Bill Wright wrote:
"Paul Martin" wrote in message
...
In article ,
Of course, it does nothing to relieve the world of 500W halogen yard
search lights.

What's the alternative?

High pressure sodium or mercury vapour discharge lights are not bad for
lots of light of moderate quality. Used in combination the pinkish and
blueish tinges can work well together. Not much good for short period
lighting on a PIT though.

But a 150W halogen lamp would actually suffice for many. Our back garden
is amply lit by one - stays on for maybe a couple of minutes as needed.
Others in the area light similarly sized gardens with 500W left on for
hours/all night.

--
Rod

charles wrote:
In article , dennis@home
wrote:


"J G Miller" wrote in message
news
On Sun, 27 Sep 2009 21:31:57 +0100, The Natural Philosopher wrote:
WE have totally inadequate wind rain and places to generate hydro pwer.
Then why did there used to be a power utility called The North of
Scotland Hydro-Electric Board which generated and distributed
electrical energy to Northern Scotland?

We have hydro plants on streams that can generate a couple kilowatts, it
doesn't mean we can supply the whole country with clean power. They are
just inadequate for the job.

The above organisation, in its current guise of Scottish & Southern Energy,
has just commissioned a new 100MW hydro scheme at Glendoe and hopes to turn
the existing Sloy scheme (at 153MW - the biggest in the country) into a
pumped storage one. so much for "streams generating a couple of kilowatts"

well with a typical power station being somewhere upwards of a Gw, and
our total energy needs as a country running at an estimated 300GW, I
cant see those making a huge difference to anything.

J G Miller wrote:
On Sun, 27 Sep 2009 23:06:32 +0100, dennis@home wrote:

You can not supply enough hydro electric power in the UK for it to solve
our energy problems.

Nobody has claimed that hydro electric power generation *alone* can provide
the total electrical energy requirements of the UKofGB&NI.

Ah the old chestnut, 'if it cant do it all, that doesn't make it not
worth doing'

True enough IF, and its a very big IF, its not promoted as being THE
answer, it is sufficiently cheap to compete fairly with other
technologies, and it does not have huge implications in terms of
environmental impact.

IF you have the right geography, the second condition can be met by
hydro power. There will always be arguments about the third, drastically
modifying the natural landscape to create artificial dams.

In the case of windpower, it cannot even compete on cost grounds, let
alone environmental impact. Except in a very few cases where to install
other technology by dint of geography is even MORE expensive.

J G Miller wrote:
On Sun, 27 Sep 2009 22:26:11 +0100, dennis@home wrote:

We have hydro plants on streams that can generate a couple kilowatts

Sounds like Scottish Power generate more than a *couple of kilowatts* to me
from hydro electric schemes --

Lanark Hydro Electric Scheme 17 MW


About the same as a big diesel generator. Enough to run one electric
train line maybe..

Galloway Hydro Electric Scheme 106.5 MW

Better. But still no banana.

we need 3000 like that to supply the whole country.

Java Jive wrote:
Adequately answered by others.

who agree. We have almost no hydro POTENTIAL at all. every suitable site
has already been utilised.

And generates a few megawatts..maybe a gigawatt in total, across thee
whole country.

"Java Jive" wrote in message
...

It was tilted massively towards big centralised power generation in
the post-war years, with large government investments in places like
Windscale and Dounreay,

Have you not worked it out yet?
Neither of those were power stations, never have been, never were intended
to be.

and through the CEGB commissioning the first
rounds of nuclear power stations.

CalderHall?
Intended to supply some of the power needed to run the plutonium
manufacturing process.

In article ,
Rod wrote:
John Rumm wrote:
Bill Wright wrote:
"Paul Martin" wrote in message
...
In article ,
Of course, it does nothing to relieve the world of 500W halogen yard
search lights.

What's the alternative?

High pressure sodium or mercury vapour discharge lights are not bad for
lots of light of moderate quality. Used in combination the pinkish and
blueish tinges can work well together. Not much good for short period
lighting on a PIT though.

But a 150W halogen lamp would actually suffice for many. Our back garden
is amply lit by one - stays on for maybe a couple of minutes as needed.
Others in the area light similarly sized gardens with 500W left on for
hours/all night.

"but a 150w halogen"? Why not use a 40w sodium? We use two in our Village
Hall car park.

--
From KT24

Using a RISC OS computer running v5.11

In article , The Natural Philosopher
wrote:
charles wrote:
In article , dennis@home
wrote:


"J G Miller" wrote in message
news On Sun, 27 Sep 2009 21:31:57 +0100, The Natural Philosopher wrote:
WE have totally inadequate wind rain and places to generate hydro
pwer.
Then why did there used to be a power utility called The North of
Scotland Hydro-Electric Board which generated and distributed
electrical energy to Northern Scotland?

We have hydro plants on streams that can generate a couple kilowatts,
it doesn't mean we can supply the whole country with clean power. They
are just inadequate for the job.

The above organisation, in its current guise of Scottish & Southern
Energy, has just commissioned a new 100MW hydro scheme at Glendoe and
hopes to turn the existing Sloy scheme (at 153MW - the biggest in the
country) into a pumped storage one. so much for "streams generating a
couple of kilowatts"

well with a typical power station being somewhere upwards of a Gw, and
our total energy needs as a country running at an estimated 300GW, I
cant see those making a huge difference to anything.

on that basis - forget wind power

--
From KT24

Using a RISC OS computer running v5.11

"The Natural Philosopher" wrote in message
...

well with a typical power station being somewhere upwards of a Gw, and our
total energy needs as a country running at an estimated 300GW, I cant see
those making a huge difference to anything.

I can, hydro electric are easy to control and respond quickly.
Run them at the bare minimum and you can turn them up to smooth supply
during peaks.
Pretty much like the pumped hydro stations but not as big.

"charles" wrote in message
...


But a 150W halogen lamp would actually suffice for many. Our back garden
is amply lit by one - stays on for maybe a couple of minutes as needed.
Others in the area light similarly sized gardens with 500W left on for
hours/all night.

"but a 150w halogen"? Why not use a 40w sodium? We use two in our
Village
Hall car park.

Because you can't turn the sodium lights off and on quickly so the silly
buggers leave them on all the time causing light pollution and wasting
energy.
A 150W halogen on a PIR or two is much better, it wastes less energy, it is
brighter, it is whiter, and you can see intruders as it goes from dark to
light suddenly.

charles wrote:


"but a 150w halogen"? Why not use a 40w sodium? We use two in our Village
Hall car park.


If I understand how these things work and how they can be fitted, that
would imply replacing the whole light fixture. At least a 150W halogen
can be a direct replacement - reducing energy usage by around 2/3.
(Actually, most of the time, a 40W halogen would suffice our needs!)

For a new installation maybe sodium would be best? But more expensive to
purchase, it seems. But maybe trained glow flies are the way forward...

--
Rod

On Sun, 27 Sep 2009 23:53:03 +0100, Paul Martin wrote:

Subsidising wind power is distorting the market.

Any subsidies distort the market but having said that letting the
market decide can be equally bad in the long run as the result is
then more down to who can spend the most on marketing rather than
what is actually a good product.

It's a political move that smacks of the short term thinking that is
endemic in high level decisions these days.

Hopefully the near crisis that occured last winter may have actually
given those in charge a big kick up the backside to look a little bit
further than the next election.

--
Cheers
Dave.

On Mon, 28 Sep 2009 08:43:58 +0100, The Natural Philosopher wrote:

IF you have the right geography, the second condition can be met by
hydro power. There will always be arguments about the third, drastically
modifying the natural landscape to create artificial dams.

There are quite a number of dams already existant that are letting
down water all the time but there is no turbine in that water flow.
Not a great deal of energy at each but it's cheap and easy to
maintain 24/7 source of energy.

I doubt many vistors walking up to the open area of Nenthead Mines
realise that the large single garage is a 400kW hydro plant.


http://www.r-e-a.net/installations/n...ydro-power-ltd

Which led me to:

http://www.r-e-a.net/installations/sites_map

134 "Micro" hydro stations
172 20MW hydro stations
17 "large" hydro stations

Without digging for the rest of the morning (the float over on the
map doesn't give capacity of each station) it looks like the
installed UK hydro capacity is 4 to 5GW.

--
Cheers
Dave.

On Sun, 27 Sep 2009 22:24:14 +0000 (UTC), J G Miller wrote:

We have hydro plants on streams that can generate a couple
kilowatts

Sounds like Scottish Power generate more than a *couple of kilowatts* to
me from hydro electric schemes --

Lanark Hydro Electric Scheme 17 MW
Galloway Hydro Electric Scheme 106.5 MW

Sloy 152MW
Foyers 300MW

....

--
Cheers
Dave.

On Mon, 28 Sep 2009 08:50:41 +0100, The Natural Philosopher wrote:

Galloway Hydro Electric Scheme 106.5 MW

Better. But still no banana.

But better than the 150+ wind turbines that would be required
scattered across the country to even have a hope of providing that
amount of power more or less 24/7.


--
Cheers
Dave.