On Thu, 03 Nov 2011 13:44:17 +0000, Roger Chapman wrote:

On 03/11/2011 12:05, Tony Bryer wrote:

If there are ever enough domestic PV panels to avoid building
yet another extra power station then the excessively high FITs do
make some sort of sense.

But AIUI that can never happen in the UK since peak demand is on winter
evenings.

I don't have an figures to hand but ISTR that total demand peaks during
the day when most workers are hard at work rather than generating
tea-break spikes when their favourite TV programs end.

Seems to be about 1700...

http://www.bmreports.com/bsp/bsp_home.htm


--
Use the BIG mirror service in the UK:
http://www.mirrorservice.org

*lightning protection* - a w_tom conductor

John Rumm wrote:

On 03/11/2011 12:30, tony sayer wrote:

We have a job to do to control some lights, in essence similar to the
PIR operated light in your front garden except that this is Six separate
lights around 2 kW in total load.

The lights are in shall we say, very awkward locations and are a PITA to
get to. It seems to me that if we under run them a bit then their
lifetime before replacement might be extended. There is a fair old bit
of cable run in this too so its prolly going to loose a bit anyway..

What also seems like a good idea is to soft start them i.e. just fade up
the volts applied over a second or so to reduce the switch on surge when
cold.

We have a simple infra red light beam detector arrangement that will
give a contact closure when triggered

What about step starting? Fire up the lights in series pairs, and then a
couple of secs later hit them with full volts? Just need a couple of
relays and a simple timer that way.

Without having to rewire the lights, if you popped a diode in
series for the soft start condition, that would give you half
volts. Some heaters use that method to give stepped control.

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.

On Nov 3, 1:11*pm, John Rumm wrote:
On 03/11/2011 12:30, tony sayer wrote:

Anyone here know if one of these exists?.

Did you mean to post this to the FiT thread...?



We have a job to do to control some lights, in essence similar to the
PIR operated light in your front garden except that this is Six separate
lights around 2 kW in total load.

The lights are in shall we say, very awkward locations and are a PITA to
get to. It seems to me that if we under run them a bit then their
lifetime before replacement might be extended. There is a fair old bit
of cable run in this too so its prolly going to loose a bit anyway..

What also seems like a good idea is to soft start them i.e. just fade up
the volts applied over a second or so to reduce the switch on surge when
cold.

We have a simple infra red light beam detector arrangement that will
give a contact closure when triggered which we could interpose another
relay to source volts to the larger relay. If that one could accept
either a simple contact close or volts applied say 12 to 24 then fine.

If it can also stay switched on for a time period perhaps a minute or
so then better still.

What about step starting? Fire up the lights in series pairs, and then a
couple of secs later hit them with full volts? Just need a couple of
relays and a simple timer that way.


Tony hasnt mentioned which type of lights they are, it makes a big
difference as to what works and what doesnt.

Switchover from series to parallel working can be done with a relay
driven by rectifier, R,C. But in the case of GLS lamps, it makes close
to zero difference to life expectancy.


NT

In article .
com, NT scribeth thus
On Nov 3, 1:11*pm, John Rumm wrote:
On 03/11/2011 12:30, tony sayer wrote:

Anyone here know if one of these exists?.

Did you mean to post this to the FiT thread...?

Err.. no its been "moved" now;!..




We have a job to do to control some lights, in essence similar to the
PIR operated light in your front garden except that this is Six separate
lights around 2 kW in total load.

The lights are in shall we say, very awkward locations and are a PITA to
get to. It seems to me that if we under run them a bit then their
lifetime before replacement might be extended. There is a fair old bit
of cable run in this too so its prolly going to loose a bit anyway..

What also seems like a good idea is to soft start them i.e. just fade up
the volts applied over a second or so to reduce the switch on surge when
cold.

We have a simple infra red light beam detector arrangement that will
give a contact closure when triggered which we could interpose another
relay to source volts to the larger relay. If that one could accept
either a simple contact close or volts applied say 12 to 24 then fine.

If it can also stay switched on for a time period perhaps a minute or
so then better still.

What about step starting? Fire up the lights in series pairs, and then a
couple of secs later hit them with full volts? Just need a couple of
relays and a simple timer that way.


Tony hasnt mentioned which type of lights they are, it makes a big
difference as to what works and what doesnt.

Switchover from series to parallel working can be done with a relay
driven by rectifier, R,C. But in the case of GLS lamps, it makes close
to zero difference to life expectancy.


Yes standard security filament lights like the sort used in PIR
operated ones like as used on the front of your house...

like these ones..

http://www.tlc-direct.co.uk/Products/LATH500.html

NT

--
Tony Sayer

On 03/11/11 10:57, tony sayer wrote:

I have long thought that we ought to split the UK into the land of the
left, hippies, greenies, other nuisances, spongers, dole cheats and
protesters and the other bit to contain those who live in the real work
who work.....


+1

Course the former it could be called La-La land or Greenwashire?...

The Green ****pot

--
djc

On 03/11/11 11:00, tony sayer wrote:
In article
s.com, harry scribeth thus


Even the arabs are installing vast arrays.

Well how much land is there thats lit by large amounts of sun there?.
Now much electricity do they need anyway?. Ever been there?..

and a peak demand for air-conditioning when the sun is shining.

--
djc

On 03/11/2011 14:11, Bob Eager wrote:
On Thu, 03 Nov 2011 13:44:17 +0000, Roger Chapman wrote:

On 03/11/2011 12:05, Tony Bryer wrote:

If there are ever enough domestic PV panels to avoid building
yet another extra power station then the excessively high FITs do
make some sort of sense.

But AIUI that can never happen in the UK since peak demand is on winter
evenings.

I don't have an figures to hand but ISTR that total demand peaks during
the day when most workers are hard at work rather than generating
tea-break spikes when their favourite TV programs end.

Seems to be about 1700...

http://www.bmreports.com/bsp/bsp_home.htm

Seems I was wrong.

Site took an age to load but contains interesting information about
current circumstances. The System demand curve is a weird shape. Down to
little more than half peak demand in the early hours (approx 4am) which
is only to be expected but daytime demand is virtually on a plateau from
9am to 4pm at 87% of peak with a sharp peak above 87% between 4 and 8pm,
by which time demand is falling steeply. I wonder what factors cause
that peak.


--
Roger Chapman

Roger Chapman wrote:
On 03/11/2011 14:11, Bob Eager wrote:
On Thu, 03 Nov 2011 13:44:17 +0000, Roger Chapman wrote:

On 03/11/2011 12:05, Tony Bryer wrote:

If there are ever enough domestic PV panels to avoid building
yet another extra power station then the excessively high FITs do
make some sort of sense.

But AIUI that can never happen in the UK since peak demand is on winter
evenings.

I don't have an figures to hand but ISTR that total demand peaks during
the day when most workers are hard at work rather than generating
tea-break spikes when their favourite TV programs end.

Seems to be about 1700...

http://www.bmreports.com/bsp/bsp_home.htm

Seems I was wrong.

Site took an age to load but contains interesting information about
current circumstances. The System demand curve is a weird shape. Down to
little more than half peak demand in the early hours (approx 4am) which
is only to be expected but daytime demand is virtually on a plateau from
9am to 4pm at 87% of peak with a sharp peak above 87% between 4 and 8pm,
by which time demand is falling steeply. I wonder what factors cause
that peak.

Millions of microwave ovens and kettles making TV meals. Fan heaters
warming up cold rooms after a day of being empty, before the central
heating gets going properly.

--
Tciao for Now!

John.

On 2 Nov,
"Dave Liquorice" wrote:

Not with the total installed capacity of less than 1% of demand. ISTR
they work with a 20% margin of spinning reserve. So if a nuke station
and a big coal fired station fall off line at the same time (say
3,400,000 kW) the grid struggles but doesn't collapse.

That happened a couple of years ago when a Scottish coal fired station
(Longannet?) fell off at the same time as a nuclear. The system survived, but
some cuts and voltage reductions were needed in the short term.

--
B Thumbs
Change lycos to yahoo to reply

On 03/11/2011 16:20, Tim Streater wrote:
In article ,
Bob Eager wrote:

On Thu, 03 Nov 2011 13:44:17 +0000, Roger Chapman wrote:

On 03/11/2011 12:05, Tony Bryer wrote:
If there are ever enough domestic PV panels to avoid building
yet another extra power station then the excessively high FITs do
make some sort of sense.
But AIUI that can never happen in the UK since peak demand is on
winter
evenings.
I don't have an figures to hand but ISTR that total demand peaks
during
the day when most workers are hard at work rather than generating
tea-break spikes when their favourite TV programs end.

Seems to be about 1700...

http://www.bmreports.com/bsp/bsp_home.htm

Time for TNP to advertise this again:

http://www.gridwatch.templar.co.uk/

That at least loads instantly and has a bit more of the historic record.
Is the missing start to the annual stats because the site hasn't been
running that long or is there some deeper reason?

--
Roger Chapman

Roger Chapman wrote:
On 03/11/2011 16:20, Tim Streater wrote:
In article ,
Bob Eager wrote:

On Thu, 03 Nov 2011 13:44:17 +0000, Roger Chapman wrote:

On 03/11/2011 12:05, Tony Bryer wrote:
If there are ever enough domestic PV panels to avoid building
yet another extra power station then the excessively high FITs do
make some sort of sense.
But AIUI that can never happen in the UK since peak demand is on
winter
evenings.
I don't have an figures to hand but ISTR that total demand peaks
during
the day when most workers are hard at work rather than generating
tea-break spikes when their favourite TV programs end.

Seems to be about 1700...

http://www.bmreports.com/bsp/bsp_home.htm

Time for TNP to advertise this again:

http://www.gridwatch.templar.co.uk/

That at least loads instantly and has a bit more of the historic record.
Is the missing start to the annual stats because the site hasn't been
running that long or is there some deeper reason?

Also, what happened last Thursday? The daytime plateau is much lower
than on any other weekday on the graph.

--
Tciao for Now!

John.

On 03/11/11 15:12, Roger Chapman wrote:

http://www.bmreports.com/bsp/bsp_home.htm

Seems I was wrong.

Site took an age to load but contains interesting information about
current circumstances. The System demand curve is a weird shape. Down to
little more than half peak demand in the early hours (approx 4am) which
is only to be expected but daytime demand is virtually on a plateau from
9am to 4pm at 87% of peak with a sharp peak above 87% between 4 and 8pm,
by which time demand is falling steeply. I wonder what factors cause
that peak.

At this time of year it's dark by 4pm so lights go on. Everyone still at
work, but start of rush hour so lots of suburban rail lines running. At
home: kettles, toasters, heating and more lights.



--
djc

On Thu, 03 Nov 2011 10:23:52 +0000, The Natural Philosopher
wrote:

Dave Liquorice wrote:
On Wed, 2 Nov 2011 10:25:06 +0000, tony sayer wrote:

Also if my PV packs in, it is not a national disaster as it would
be
if a major primary substation/power station had problems.
Umm .. when did that happen last with serious consequences?..

Sizewell B and Longannet going off line in quick succesion with the
loss of 1,510,000 kW generation gave the grid summat to think about
in May 2008. Load was shed, ie people had power cuts and most of the
country noticed the dip in voltage and then further voltage
reductions.

That's no worse than the wind dying over the whole country. We are
having to cope with that sort of loss on a weekly basis now.

It's a lot worse, the incident mentioned above happened in a two
minute timescale. If the wind suddenly stopped across the UK in the
space of 2 minutes I'd get really worried.

P.S. I despise wind power.


--

On Thu, 03 Nov 2011 16:29:51 GMT, wrote:

On 2 Nov,
"Dave Liquorice" wrote:

Not with the total installed capacity of less than 1% of demand. ISTR
they work with a 20% margin of spinning reserve. So if a nuke station
and a big coal fired station fall off line at the same time (say
3,400,000 kW) the grid struggles but doesn't collapse.

That happened a couple of years ago when a Scottish coal fired station
(Longannet?) fell off at the same time as a nuclear. The system survived, but
some cuts and voltage reductions were needed in the short term.

That wasn't 3.4GW, it was around 1.5GW in less than 2 minute.


--

On Thu, 03 Nov 2011 10:17:20 +0000, The Natural Philosopher
wrote:

The major contribution of *any* power station is reducing demand on the
grid to exactly zero, overall.

Maybe you possibly meant to say increasing generation until the system
is balanced

generation = demand+losses

In the distant past before privatisation that was correct but now not
all generators perform balancing, reduce the system frequency and the
system voltage and they will deliberately continue at their previous
power output until they drop off the bars on low system volts or low
system frequency.

--

On Nov 3, 11:00*am, Roger Chapman wrote:
On 03/11/2011 09:47, John Rumm wrote:



On 02/11/2011 09:04, harry wrote:
On Nov 1, 7:28 pm, wrote:
"Roger wrote in message

. ..

Harry appears to have invested some £15,000 and if we assume his 8%
so far
this year translates into 10% over the course of a full year he will be
lucky to get all his capital back in ten years as the FIT reduces
year by
year.

Harry's fit doesn't reduce year by year, it goes up as its index linked.
It was intended that *new* installations would start at a lower rate
of fit
each year.
Now they are halving it on *new* installations.

Exactly so. But I still think they will be viable, prices for
installation are falling.

When they cost less to install and maintain, than the cost of the
electricity they save, then they might be "viable".

That is likely to be never.

But look at it another way. Water Companies have been encouraging
customers to save water on the premise that avoiding building yet more
reservoirs saves both considerable capital investment and endless hassle
from the NIMBIES. If there are ever enough domestic PV panels to avoid
building yet another extra power station then the excessively high FITs
do make some sort of sense.

Up message I suggested that Harry would get his capital back in 10 years
but that is too simplistic a viewpoint for an investor expecting to make
say 10% pa on capital invested. The annual return (FIT + reduced usage +
export) needs to exceed the expected 10% before any of the capital is
recovered and in the initial year at least it is quite easy to construct
a scenario where the annual return is less than 10% so the hypothetical
capital invested goes up instead of down. It is only inflation that will
eventually allow that 10% return. Without the FIT going up in line with
RPI and electricity costs for consumers going up even faster the return
would be much less before the panels die of old age and with a FIT of
21p quite possibly nothing more than money back with no interest earned
at all.

Somewhere up thread is a comment (which I now can't find) that the
decline in efficiency of the panels is slight but it doesn't need to be
much (say 5% reduction in net efficiency pa) to completely torpedo the
investment potential. So does anyone have figures for the actual rate of
decay? All I can find atm is that the average panel starts life with an
efficiency in the region of 15% which doesn't really help.
--
Roger Chapman- Hide quoted text -

- Show quoted text -

!%/ year (max) is the oft quoted rate of "decay".
Yes , I take inflation into account. If you have money in the bank
you can't even keep up with inflation.
I think when this scheme was dreamt up, they knew they would have to
get a better return than the interest rates at THAT time for anyone to
be interested.

BTW I seenow where all the drivelon here is coming from, the DM asyou
might expect (Nov !st).
90 % of the article is lies and misstatements.

On Nov 3, 11:00*am, tony sayer wrote:
In article
s.com, harry scribeth thus





On Nov 2, 7:12*pm, tony sayer wrote:
Heh Heh. We are all going to have to use a lot less energy in our
brave new world. *I am now a negative energy user. If everyone was a
negative energy user there would be power for commerce and industry.
My negative energy utility will be good for 25 years, the insulation
for over a hundred. *I think it will pay back the energy invested in
it's manufacture in a hundred years.

Why is this? Because it is a passive energy saver, it has no moving
parts and needs no maintenence.

Do you think it could power industry and run the trains etc then;?..

especially at night..
--
Tony Sayer

Of course not at night. *But it helps lop the daily electricity peak.
Are you being obtuse or just stupid?

No realistic .. and thats based on good engineering overall not just a
silly scheme dreamt up by a misguided government to do something looking
Green;!...

Even the arabs are installing vast arrays.

Well how much land is there thats lit by large amounts of sun there?.
Now much electricity do they need anyway?. Ever been there?..
--
Tony Sayer- Hide quoted text -

- Show quoted text -

Travelled extensively in the ME.

On Nov 3, 12:05*pm, Tony Bryer wrote:
On Thu, 03 Nov 2011 11:00:38 +0000 Roger Chapman wrote :

If there are ever enough domestic PV panels to avoid building
yet another extra power station then the excessively high FITs
do make some sort of sense.

But AIUI that can never happen in the UK since peak demand is on
winter evenings.

If public money was to be spent encouraging the industry and in
providing an element of green power, it would have made more sense
to finance the installation of panels on buildings such as
libraries and hospitals where there is a local use for the power
being generated.

--
Tony Bryer, *Greentram: 'Software to build on',
Melbourne, Australia * * *www.greentram.com

There are two peaks. One, commerce and industry by day. The other TV
and tea in the evening.

"Dave Liquorice" wrote in message
ll.co.uk...

I suspect there is far higher risk from the death wish motorcylists who
blast along the local roads taking right hand bends with their wheels
just their side of the line but their head about in line with the
windscreen A frame of a car going in the opposite direction...

That's not a problem the A frame is strong enough to stop them coming
through the screen.
Its the ones who don't hit the A frame that will kill you.
There should be a driving simulator available so you can practice getting
the A frame in the correct position without damaging the car.

On 02/11/2011 12:27, The Natural Philosopher wrote:
Roger Chapman wrote:
On 01/11/2011 12:54, RobertL wrote:

To a parent privileges such as child allowance are an inalienable
right but how ethical is taxing the childless poor so that someone who
already has a larger income and a more comfortable existence is
further rewarded for a particular lifestyle choice.


Exactly.

Iniquitous.

I don't know about that. Those poor will not build up a decent pension
pot and without children, they will be relying upon the children of
others to look after them, pay tax, etc. when they are retired. If
anything, it is an investment in their own futures!

SteveW

On 03/11/2011 10:52, The Natural Philosopher wrote:
Tim Streater wrote:
In article ,
Tim Watts wrote:

harry wrote:

Unless you want to risk nuclear
Yes please. The hippies can go and live on Skye and get cold. I want
my electricity. I have no problems having a power station down the road.

And it's less radioactive than your coal fired power station, which is
pushing radon into the atmosphere. Remember that.

Its a lot less radioactive than an X ray or especially a CAT scan.

Most CAT scans are MRI these days, and not ionising at all.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Thu, 03 Nov 2011 16:29:51 GMT, wrote:


Not with the total installed capacity of less than 1% of demand.
ISTR
they work with a 20% margin of spinning reserve. So if a nuke
station
and a big coal fired station fall off line at the same time (say
3,400,000 kW) the grid struggles but doesn't collapse.

That happened a couple of years ago when a Scottish coal fired station
(Longannet?) fell off at the same time as a nuclear. The system
survived, but some cuts and voltage reductions were needed in the short
term.

No the affects lasted into the evening with the grid having to issue
several warnings and one that indicated power cuts were very likely
to happen (but didn't).

And yes it was 1,510,000 kW loss when Longganet and Sizewell B
dropped off.
--
Cheers
Dave.

"John Rumm" wrote in message
o.uk...


Most CAT scans are MRI these days, and not ionising at all.

I think you will find cat scans are not the same as mri.
Cat scans are good for bones and dyes, mri is good for soft tissue and not
so good for bones (no water) and doesn't know what a dye is.

On Thu, 3 Nov 2011 19:47:05 -0000, "dennis@home"
wrote:



"Dave Liquorice" wrote in message
ill.co.uk...

I suspect there is far higher risk from the death wish motorcylists who
blast along the local roads taking right hand bends with their wheels
just their side of the line but their head about in line with the
windscreen A frame of a car going in the opposite direction...

There's always more gap than there looks to be. Unless there isn't, of
course.

That's not a problem the A frame is strong enough to stop them coming
through the screen.
Its the ones who don't hit the A frame that will kill you.
There should be a driving simulator available so you can practice getting
the A frame in the correct position without damaging the car.

A post/pillar.

On 3 Nov,
The Other Mike wrote:

On Thu, 03 Nov 2011 16:29:51 GMT, wrote:

On 2 Nov,
"Dave Liquorice" wrote:

Not with the total installed capacity of less than 1% of demand. ISTR
they work with a 20% margin of spinning reserve. So if a nuke station
and a big coal fired station fall off line at the same time (say
3,400,000 kW) the grid struggles but doesn't collapse.

That happened a couple of years ago when a Scottish coal fired station
(Longannet?) fell off at the same time as a nuclear. The system survived, but
some cuts and voltage reductions were needed in the short term.

That wasn't 3.4GW, it was around 1.5GW in less than 2 minute.

I was referring to the coal and nuke failing, not the power level. The system
/just/ survived at that level. 4GW would prolly bring down the system but
would need two complete stations(unless Drax A and B together) failing at
full output. As each station has multiple generators of maximum 660MW each,
then that's extremely unlikely.

--
B Thumbs
Change lycos to yahoo to reply

harry writes:

Of course not at night. But it helps lop the daily electricity peak.
Are you being obtuse or just stupid?
Even the arabs are installing vast arrays.

Because _for them_ it makes very good sense.

--
Windmill, Use t m i l l
J.R.R. Tolkien:- @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost

tony sayer writes:

Anyone here know if one of these exists?.

We have a job to do to control some lights, in essence similar to the
PIR operated light in your front garden except that this is Six separate
lights around 2 kW in total load.

The lights are in shall we say, very awkward locations and are a PITA to
get to. It seems to me that if we under run them a bit then their
lifetime before replacement might be extended. There is a fair old bit
of cable run in this too so its prolly going to loose a bit anyway..

If the bulbs are 300 watts each this idea might be relevant.

One can put a current surge limiter in series with each bulb,
basically a resistor whose resistance _falls_ as it warms up.

Very old technology first used to give a soft start when a string of
valve filaments ('heaters') were wired in series so that a radio could
run off 240v. without needing a power transformer. (One filament tended
to get an unbalanced, high voltage until everything warmed up, and this
approach prevented that).
Showing my age, I s'pose.

An old DigiKey catalog(ue) lists an 'inrush current limiter' which has
a resistance of 120 ohms cold and 1 ohm when hot, with a max. current
of 2 amps.
A 240 volt 300 watt bulb would have a resistance of about 190 ohms when
on, so the 1 ohm series resistance wouldn't dim it much.
The cold resistance of a tungsten filament in a bulb is about 1/10
of the hot resistance, about 19 ohms in this case (meaning an inrush
current of over 12 amps, which is why bulbs fail so often when first
switched on). However this series current limiter would reduce that to
around 1.7 amps.

The current limiter dissipates around 1.5 watts so gets a little warm.
Needs a metal box.

Did this once for someone who complained about the short life of
reflector floodlamps, but he didn't like it that the light switch
became a little warm.



--
Windmill, Use t m i l l
J.R.R. Tolkien:- @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost

On Nov 3, 9:59*pm, "dennis@home" wrote:
"John Rumm" wrote in message

o.uk...

Most CAT scans are MRI these days, and not ionising at all.

I think you will find cat scans are not the same as mri.
Cat scans are good for bones and dyes, mri is good for soft tissue and not
so good for bones (no water) and doesn't know what a dye is.

CAT
Computer Automated Tomography.
Just refers to how the data obtained is processed.
It can be Xray or Magnetic Resonance Imaging.
So you are both right.

On Nov 4, 3:28*am, (Windmill)
wrote:
harry writes:
Of course not at night. *But it helps lop the daily electricity peak.
Are you being obtuse or just stupid?
Even the arabs are installing vast arrays.

Because _for them_ it makes very good sense.

--
Windmill, * * * * * * * Use *t m i l l
J.R.R. Tolkien:- * * * * * * * * * * * * * * * * * @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost

When they have all that oil and an existing infra structure?
As it runs out, it will be us that are deperived before they are.
And it is running out.
The Saudis are building nuclear power stations too.

In article , djc
scribeth thus
On 03/11/11 11:00, tony sayer wrote:
In article
s.com, harry scribeth thus


Even the arabs are installing vast arrays.

Well how much land is there thats lit by large amounts of sun there?.
Now much electricity do they need anyway?. Ever been there?..

and a peak demand for air-conditioning when the sun is shining.


Yes well thats when the sun is shining!. No large industry no surge in
demand for trains like the large UK cities ....
--
Tony Sayer

In article
..com, harry scribeth thus
On Nov 3, 11:00*am, tony sayer wrote:
In article
s.com, harry scribeth thus





On Nov 2, 7:12*pm, tony sayer wrote:
Heh Heh. We are all going to have to use a lot less energy in our
brave new world. *I am now a negative energy user. If everyone was a
negative energy user there would be power for commerce and industry.
My negative energy utility will be good for 25 years, the insulation
for over a hundred. *I think it will pay back the energy invested in
it's manufacture in a hundred years.

Why is this? Because it is a passive energy saver, it has no moving
parts and needs no maintenence.

Do you think it could power industry and run the trains etc then;?..

especially at night..
--
Tony Sayer

Of course not at night. *But it helps lop the daily electricity peak.
Are you being obtuse or just stupid?

No realistic .. and thats based on good engineering overall not just a
silly scheme dreamt up by a misguided government to do something looking
Green;!...

Even the arabs are installing vast arrays.

Well how much land is there thats lit by large amounts of sun there?.
Now much electricity do they need anyway?. Ever been there?..
--
Tony Sayer- Hide quoted text -

- Show quoted text -

Travelled extensively in the ME.

Then you'll know that if this PV tech might stand a change of doing
anything useful then thats where it will!...
--
Tony Sayer

In article , Windmill spam-no-
lid scribeth thus
tony sayer writes:

Anyone here know if one of these exists?.

We have a job to do to control some lights, in essence similar to the
PIR operated light in your front garden except that this is Six separate
lights around 2 kW in total load.

The lights are in shall we say, very awkward locations and are a PITA to
get to. It seems to me that if we under run them a bit then their
lifetime before replacement might be extended. There is a fair old bit
of cable run in this too so its prolly going to loose a bit anyway..

If the bulbs are 300 watts each this idea might be relevant.

One can put a current surge limiter in series with each bulb,
basically a resistor whose resistance _falls_ as it warms up.

Very old technology first used to give a soft start when a string of
valve filaments ('heaters') were wired in series so that a radio could
run off 240v. without needing a power transformer. (One filament tended
to get an unbalanced, high voltage until everything warmed up, and this
approach prevented that).
Showing my age, I s'pose.

Well I do remember them and barretters;!..


An old DigiKey catalog(ue) lists an 'inrush current limiter' which has
a resistance of 120 ohms cold and 1 ohm when hot, with a max. current
of 2 amps.
A 240 volt 300 watt bulb would have a resistance of about 190 ohms when
on, so the 1 ohm series resistance wouldn't dim it much.
The cold resistance of a tungsten filament in a bulb is about 1/10
of the hot resistance, about 19 ohms in this case (meaning an inrush
current of over 12 amps, which is why bulbs fail so often when first
switched on). However this series current limiter would reduce that to
around 1.7 amps.


Might look into that, after all the simplest ideas are often the
best..

The current limiter dissipates around 1.5 watts so gets a little warm.
Needs a metal box.

No problem where this is going and its not likely to be on that long
either..

Did this once for someone who complained about the short life of
reflector floodlamps, but he didn't like it that the light switch
became a little warm.




--
Tony Sayer

In article .
com, harry scribeth thus
On Nov 3, 9:59*pm, "dennis@home" wrote:
"John Rumm" wrote in message

o.uk...

Most CAT scans are MRI these days, and not ionising at all.

I think you will find cat scans are not the same as mri.
Cat scans are good for bones and dyes, mri is good for soft tissue and not
so good for bones (no water) and doesn't know what a dye is.

CAT
Computer Automated Tomography.


Umm...

Computer Axial Tomography ...


Just refers to how the data obtained is processed.
It can be Xray or Magnetic Resonance Imaging.
So you are both right.

--
Tony Sayer

On Fri, 04 Nov 2011 01:05:01 GMT, wrote:

I was referring to the coal and nuke failing, not the power level. The
system /just/ survived at that level. 4GW would prolly bring down the
system but would need two complete stations(unless Drax A and B
together) failing at full output. As each station has multiple
generators of maximum 660MW each, then that's extremely unlikely.

How many coal conveyours are there are drax? When that failed at
Longgannet it was off for a few weeks... But I agree losing 4GW in a
short (hours) space of time would give the grid serious trouble, how
bad would depend on what was available to bring online quickly. Part
of the 2008 problem was that they also lost a number of other smaller
stations through the afternoon, which is why affects dragged on into
evening.

--
Cheers
Dave.

On Fri, 04 Nov 2011 00:23:54 +0000, Grimly Curmudgeon wrote:

I suspect there is far higher risk from the death wish
motorcylists
who blast along the local roads taking right hand bends with
their
wheels just their side of the line but their head about in line
with
the windscreen A frame of a car going in the opposite
direction...

There's always more gap than there looks to be. Unless there isn't, of
course.

Quite, several times I've seen the fear in the riders eyes as they do
a quick twitch to slighly more upright about 15' in front of me.

--
Cheers
Dave.

On Thu, 03 Nov 2011 13:33:50 +0000, Roger Chapman
wrote:

The output of a multitude of small PV arrays is predictable to a very
large degree and relatively consistent as well. It reduces domestic
demand at a time when total demand is high and requires no hot reserve.
That PV panels produce nothing during the hours of darkness is of little
consequence because of the consistency of the output. Windmills OTOH are
as likely as not to be generating at times of lowest demand and failing
to produce even as much as PV arrays when demand is at its strongest.

AFAIK peak demand for electrickery is in the evening when people come
home from work. And, of course, the end of corrie or eastenders
triggers 1000000s of kettles to be boiled.
--
(\__/) M.
(='.'=) Due to the amount of spam posted via googlegroups and
(")_(") their inaction to the problem. I am blocking some articles
posted from there. If you wish your postings to be seen by
everyone you will need use a different method of posting.

On 03/11/2011 21:59, dennis@home wrote:


"John Rumm" wrote in message
o.uk...


Most CAT scans are MRI these days, and not ionising at all.

I think you will find cat scans are not the same as mri.
Cat scans are good for bones and dyes, mri is good for soft tissue and
not so good for bones (no water) and doesn't know what a dye is.

Indeed, you are right. I was mistakenly assuming that CAT was computer
"Aided" tomography rather than Axial. It would seem that axial is
specifically a sectional x-ray technique.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 04/11/2011 11:13, Mark wrote:
On Thu, 03 Nov 2011 13:33:50 +0000, Roger Chapman
wrote:

The output of a multitude of small PV arrays is predictable to a very
large degree and relatively consistent as well. It reduces domestic
demand at a time when total demand is high and requires no hot reserve.
That PV panels produce nothing during the hours of darkness is of little
consequence because of the consistency of the output. Windmills OTOH are
as likely as not to be generating at times of lowest demand and failing
to produce even as much as PV arrays when demand is at its strongest.

AFAIK peak demand for electrickery is in the evening when people come
home from work. And, of course, the end of corrie or eastenders
triggers 1000000s of kettles to be boiled.

Since I wrote that paragraph above it has been conclusively established
that peak demand is around 5pm. The cited soaps are not on my watchlist
but the recent schedules suggests that they finish at 8pm or later. By
8pm the demand is down to the level of the daytime plateau and falling
rapidly.

--
Roger Chapman

harry wrote:
On Nov 4, 3:28 am, (Windmill)
wrote:
harry writes:
Of course not at night. But it helps lop the daily electricity peak.
Are you being obtuse or just stupid?
Even the arabs are installing vast arrays.
Because _for them_ it makes very good sense.

--
Windmill, Use t m i l l
J.R.R. Tolkien:- @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost

When they have all that oil and an existing infra structure?
As it runs out, it will be us that are deperived before they are.
And it is running out.
The Saudis are building nuclear power stations too.

Using the oil revenue to build stuff for when it runs out. Very sensible
of them. They'll also probably be in a position to export energy from
their non-oil plant after the oil becomes either too expensive or too
rare to burn. If we'd done that with North Sea Oil, we'd not be looking
at rolling blackouts within my expected lifetime.

--
Tciao for Now!

John.

John Williamson wrote:

harry wrote:
On Nov 4, 3:28 am, (Windmill)
wrote:
harry writes:
Of course not at night. But it helps lop the daily electricity peak.
Are you being obtuse or just stupid?
Even the arabs are installing vast arrays.
Because _for them_ it makes very good sense.

--
Windmill, Use t m i l l
J.R.R. Tolkien:- @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost

When they have all that oil and an existing infra structure?
As it runs out, it will be us that are deperived before they are.
And it is running out.
The Saudis are building nuclear power stations too.

Using the oil revenue to build stuff for when it runs out. Very sensible
of them. They'll also probably be in a position to export energy from
their non-oil plant after the oil becomes either too expensive or too
rare to burn. If we'd done that with North Sea Oil, we'd not be looking
at rolling blackouts within my expected lifetime.


Not that we have vast areas of useless sun drenched lands to put PV on.

But if you meant "used the money to build nukes, whilst becoming a world
leader in nuclear research, safety management and waste handling" I would
agree. We could be selling the stuff over the interconnectors and selling
the manufacture, design and consultancy thereof to the rest of the world.

It's not like we were that behind in such matters in terms of personnel -
bit asleep at the time, but a single minded policy could have kickstarted
everything.

But we (they) ****ed it up the wall instead because splashing the cash buys
you mates and not having nuclear placates the tree huggers and NIMBYs.

Perhaps we should become a world leader in superconductors instead. Cheaper
research and folks'll need quite a few cables to the Middle East when they
are the only people other than the French who actually have any serious
energy production.

Libya's hot and has lots of useless deserts - they could become an economic
power if they follow the Saudies and they wouldn't even need very long
cables to export - eg Tripoli to Scicily is only about 300 miles straight
undersea. Wonder how much of Italy could be powered off the Libyan deserts?





--
Tim Watts