Incandescents are widely maligned for making much more light than heat;
but if I'm correct, in a centrally heated home that extra heat produced
by incandescents would be recycled, by helping heat the home (and
reducing heating oil bills slightly)?
Of course this means incandescents are doubly wasteful in
air-conditioned homes, although they're rare in Europe.

Seb

On Fri, 7 Oct 2005, wrote:

Incandescents are widely maligned for making much more light than heat;

itym 'more heat than light'?

but if I'm correct, in a centrally heated home that extra heat produced
by incandescents would be recycled, by helping heat the home (and
reducing heating oil bills slightly)?
Of course this means incandescents are doubly wasteful in
air-conditioned homes, although they're rare in Europe.

quite so, they are only wasteful when the heat is not 'useful' in heating
the surroundings.

Though bear in mind that electricity is rather more expensive per kWh than
gas.

--
Alistair Riddell - BOFH
Microsoft - because god hates us

In article ,
Alistair Riddell writes:
On Fri, 7 Oct 2005, wrote:

Incandescents are widely maligned for making much more light than heat;

itym 'more heat than light'?

but if I'm correct, in a centrally heated home that extra heat produced
by incandescents would be recycled, by helping heat the home (and
reducing heating oil bills slightly)?
Of course this means incandescents are doubly wasteful in
air-conditioned homes, although they're rare in Europe.

quite so, they are only wasteful when the heat is not 'useful' in heating
the surroundings.

Electricity generation is less than half as efficient as a modern
gas boiler. Heating with electricity is like heating with a 40%
efficient gas boiler, so the larger part of the energy consumed
as a result of running a light bulb goes up the flue or out of
the cooling towers at the power station. This isn't useful, ever.

--
Andrew Gabriel

wrote in message
oups.com...
Incandescents are widely maligned for making much more light than heat;
but if I'm correct, in a centrally heated home that extra heat produced
by incandescents would be recycled, by helping heat the home (and
reducing heating oil bills slightly)?
Of course this means incandescents are doubly wasteful in
air-conditioned homes, although they're rare in Europe.


Sticking a heater near the ceiling is not an effective use of energy. Yes,
they are widely maligned because using 'lighting' as a source of heat is
stupid. The heat is in the wrong place and its made using a particularly
inefficient method.

Replacing an incandescent bulb with a low energy bulb saves about £50 over
the life of the low energy bulb. It's as simple as that.

wrote in message ...
On 7 Oct,
"OG" wrote:


Sticking a heater near the ceiling is not an effective use of energy.
Yes,
they are widely maligned because using 'lighting' as a source of heat is
stupid. The heat is in the wrong place and its made using a particularly
inefficient method.

The 'old' incandescent Gas lights were certainly very effective as a heat
source in my youth - - before ceilings were insulated, too.


Yes, gas burned in the house has c100% efficiency at producing light+heat
(though the heat _was probably in the wrong place_). However, burning gas in
your not-so-local power station to produce electricity at +/- 50% efficiency
(which then produces 20% light and 80% heat (in the wrong place)) is not the
best use of energy.

wrote:
Incandescents are widely maligned for making much more light than heat;
but if I'm correct, in a centrally heated home that extra heat produced
by incandescents would be recycled, by helping heat the home (and
reducing heating oil bills slightly)?
Of course this means incandescents are doubly wasteful in
air-conditioned homes, although they're rare in Europe.

Seb

its far from the biggest problem we face, but its one that can be fixed
elementarily, and to your financial advantage by using CFLs.

Much of the year that heat isnt wanted, and for several months it only
increases indoor temps. They add to bills, are a greater fire risk than
CFLs, and need replacing around 10x as often.


NT

wrote in message
oups.com...
Incandescents are widely maligned for making much more light than heat;
but if I'm correct, in a centrally heated home that extra heat produced
by incandescents would be recycled, by helping heat the home (and
reducing heating oil bills slightly)?

Where incandescent lamps do score is that, unlike low energy lamps and
fluorescent tubes, they are not classed as hazardous waste and do not need
specialist disposal facilities.

Colin Bignell

In message , nightjar
writes

wrote in message
roups.com...
Incandescents are widely maligned for making much more light than heat;
but if I'm correct, in a centrally heated home that extra heat produced
by incandescents would be recycled, by helping heat the home (and
reducing heating oil bills slightly)?

Where incandescent lamps do score is that, unlike low energy lamps and
fluorescent tubes, they are not classed as hazardous waste and do not need
specialist disposal facilities.

.. . . and you can use them with electronic time switches

--
bof at bof dot me dot uk

Thanks sorry for typo. Yes you're right about electricity being less
efficient, although I'm in France and our rather new apartment block
uses electric heating only (probably cheaper than the UK: France got
loads of nuke stations). So no difference compared to gas. But the
other guys are right, most of the heat from incandescents go right to
the top of the ceiling (not many people up there).
About the better lifespan of fluorescents, I'd assume that it's more or
less exactly offset by their greater purchase cost?

Seb

PS You guys have been much more helpful than another environmental
newsgroup--don't wanna put down others but my posting on this topic
attracted a great big flamewar between a few others about being "Green
Goblins" but no useful answers.

Wait, are halogens hazardous?

Seb

OG wrote:
wrote in message ...

On 7 Oct,
"OG" wrote:



Sticking a heater near the ceiling is not an effective use of energy.
Yes,
they are widely maligned because using 'lighting' as a source of heat is
stupid. The heat is in the wrong place and its made using a particularly
inefficient method.

The 'old' incandescent Gas lights were certainly very effective as a heat
source in my youth - - before ceilings were insulated, too.



Yes, gas burned in the house has c100% efficiency at producing light+heat
(though the heat _was probably in the wrong place_). However, burning gas in
your not-so-local power station to produce electricity at +/- 50% efficiency
(which then produces 20% light and 80% heat (in the wrong place)) is not the
best use of energy.



That energy efficiency could probably be upped a lot (In the winter
anyway) if they installed underground pipes to local houses, shops,
businesses around the powerstations to provide them with the waste heat
(At least in the UK, because they seem to site thermal powerstations in
the middle of towns here... e.g. Slough. Although it's probably the best
looking think in slough. Maybe they did it to make the place nicer).

Would also keep the roads clear of ice if they were in tunnels under the
road...

I know they do this for some factories in NZ... e.g. The buge Anchor
milk powder factory just north of Hamilton provides hot water to local
houses... IIRC back in the early 90's they had a wee accident with
caustic soda in the water... Not so good...

On 8 Oct 2005 04:22:34 -0700, wrote:

| Thanks sorry for typo. Yes you're right about electricity being less
| efficient, although I'm in France and our rather new apartment block
| uses electric heating only (probably cheaper than the UK: France got
| loads of nuke stations). So no difference compared to gas. But the
| other guys are right, most of the heat from incandescents go right to
| the top of the ceiling (not many people up there).
| About the better lifespan of fluorescents, I'd assume that it's more or
| less exactly offset by their greater purchase cost?

Over the years, fluorescent and Energy saving lights are **much** cheaper,
especially as the price of energy saving lights has fallen to GBP3

--
Dave Fawthrop dave hyphenologist co uk
The London suicide bombers killed innocent commuters.
Animal rights terrorists and activists kill innocent patients.

wrote:
Wait, are halogens hazardous?

Seb


Halogen gases (e.g. Cl, Fl, Br etc) are pretty reactive... But I suspect
there's not enough in a bulb to hurt you. probably more Cl in your
toilet cleaner...

H

nightjar wrote:
wrote in message
oups.com...
Incandescents are widely maligned for making much more light than heat;
but if I'm correct, in a centrally heated home that extra heat produced
by incandescents would be recycled, by helping heat the home (and
reducing heating oil bills slightly)?

Where incandescent lamps do score is that, unlike low energy lamps and
fluorescent tubes, they are not classed as hazardous waste and do not need
specialist disposal facilities.

Colin Bignell


Both types of lamp contain toxic metal. Filaments contain thorium
(iirc), flouros contain mercury. Modern fls use a tiny fraction of the
amount of mercury used in older tubes, some old tubes can be a genuine
toxicity issue.

Bear in mind politics and history factor into disposal decisions as
much as anything. Metal filaments have been with us since the 1920s,
whereas CFLs are relatively modern.


NT

bof wrote:
In message , nightjar
writes

Where incandescent lamps do score is that, unlike low energy lamps and
fluorescent tubes, they are not classed as hazardous waste and do not need
specialist disposal facilities.

. . . and you can use them with electronic time switches

You can with cfls too, but there are restrictions. Its short on times
and slow warm up CFLs that are the problem combination. Also cold
outdoor conditions cause slow warm up with most types. Electrodeless
CFLs dont suffer from these issues but they cost more. And last way
longer, 10s of 1000s of hours. Although £20 a pop, they still work out
cheaper in the end.

And a few PIRs that dont have a neutral path can cause bulb flicker
while off - this applies to the all in one fittings, not to separate
PIR units.


NT

On 7 Oct 2005 18:47:06 -0700, wrote:

They add to bills, are a greater fire risk than
CFLs,

I had a CFL go wrong and overheat, charring the fitting. Fortunately
we caught it in time before the paper lampshade caught fire.

Returned it to the importer who "Couldn't find anything wrong" despite
the fact it had melted!

sponix

Hamie wrote:

That energy efficiency could probably be upped a lot (In the winter
anyway) if they installed underground pipes to local houses, shops,
businesses around the powerstations to provide them with the waste heat
(At least in the UK, because they seem to site thermal powerstations in
the middle of towns here... e.g. Slough. Although it's probably the best
looking think in slough. Maybe they did it to make the place nicer).

Would also keep the roads clear of ice if they were in tunnels under the
road...

I know they do this for some factories in NZ... e.g. The buge Anchor
milk powder factory just north of Hamilton provides hot water to local
houses... IIRC back in the early 90's they had a wee accident with
caustic soda in the water... Not so good...

In Scandinavia it is commonplace to have pavement deicing from the
district heating systems. Nice to have as your shoes last a lot longer
with no salt stains to worry about but when it stops you fall ass over
tit.

But it's not going to happen on a big scale in the UK. Most of the
significant generation is remotely located and no one really wants to
live next to a power station of virtually any type. Plus the costs of
piping and distribution of the heat only make sense when applied on a
long term basis. With a hurricane force following wind long term
planning in the UK power industry might extend to early next week.

The only way this is taking off in practice is in small scale
distributed generation with heat recovery. In effect combined heat
and power stations on the scale of a few hundred kW(e) and above.
100kW of gas fired electricity generation with waste heat recovery
costs around GBP 30k in basic capital costs, achieves around 90%+
efficiency, is almost totally silent in operation and requires next to
no maintenance. For a large block of flats or a new commercial
building they make a lot of sense IF a long term view is made.

--

In message .com,
writes
About the better lifespan of fluorescents, I'd assume that it's more or
less exactly offset by their greater purchase cost?

Ahh, but not only do they have a much longer life span, but the running
costs are a lot less - about 25%
--
Chris French

"OG" wrote in message
...


Yes, gas burned in the house has c100% efficiency at producing light+heat
(though the heat _was probably in the wrong place_). However, burning gas
in your not-so-local power station to produce electricity at +/- 50%
efficiency

Many years ago I was told the overall efficiency of generating power was in
the order of 25% taking into account generating and transmission
efficiencies. Does anyone have a link for overall electricity generation
efficiency in the UK.

In article ,
(Huge) writes:
bof writes:
In message , nightjar
writes
Where incandescent lamps do score is that, unlike low energy lamps and
fluorescent tubes, they are not classed as hazardous waste and do not need
specialist disposal facilities.

.. . . and you can use them with electronic time switches

And dimmers.

There are compact fluorescents which are dimmable with
ordinary dimmers. For some unknown reason, they aren't
imported into the UK.

Every light in my house is on either a dimmer or a timer.

Dimming incandescent lamps makes them far less efficient
then even the poor efficiency of running them at full
power gives you.

--
Andrew Gabriel

Andrew Gabriel wrote:

Dimming incandescent lamps makes them far less efficient
then even the poor efficiency of running them at full
power gives you.

Although might be worth pointing out that while the efficiency falls, so
does the power consumption - just not as fast.

--
Cheers,

John.

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

wrote:
nightjar wrote:

wrote in message
groups.com...

Incandescents are widely maligned for making much more light than heat;
but if I'm correct, in a centrally heated home that extra heat produced
by incandescents would be recycled, by helping heat the home (and
reducing heating oil bills slightly)?

Where incandescent lamps do score is that, unlike low energy lamps and
fluorescent tubes, they are not classed as hazardous waste and do not need
specialist disposal facilities.

Colin Bignell



Both types of lamp contain toxic metal. Filaments contain thorium

Tungsten. Thorium is a radioactive metal. Not used in bulb filaments
AFAIK. Google for halogen lamp. You'll get quite a few hits from
manufacturers.


(iirc), flouros contain mercury. Modern fls use a tiny fraction of the
amount of mercury used in older tubes, some old tubes can be a genuine
toxicity issue.


Yeah. I remember at school when one got smashed we all had to leave &
they had to get someone in to clean it up...

H

Andrew Gabriel andrew@a17 wrote:
In article ,
(Huge) writes:
bof writes:
In message , nightjar
writes
Where incandescent lamps do score is that, unlike low energy lamps and
fluorescent tubes, they are not classed as hazardous waste and do not need
specialist disposal facilities.

.. . . and you can use them with electronic time switches

And dimmers.

There are compact fluorescents which are dimmable with
ordinary dimmers. For some unknown reason, they aren't
imported into the UK.

Cos they'd explode.
Nobodies (as yet) made a cheap dimmable light chipset.
(well, chip)

wrote in message
oups.com...
Thanks sorry for typo. Yes you're right about electricity being less
efficient, although I'm in France and our rather new apartment block
uses electric heating only (probably cheaper than the UK: France got
loads of nuke stations). So no difference compared to gas. But the
other guys are right, most of the heat from incandescents go right to
the top of the ceiling (not many people up there).
About the better lifespan of fluorescents, I'd assume that it's more or
less exactly offset by their greater purchase cost?


Nope, a while back I calculated that each fluorescent saved about £50 over
its lifespan - and that was when they were £10 a pop.

Hamie wrote:
wrote:

Both types of lamp contain toxic metal. Filaments contain thorium

Tungsten. Thorium is a radioactive metal. Not used in bulb filaments
AFAIK. Google for halogen lamp. You'll get quite a few hits from
manufacturers.

Filaments are not pure tungsten, thats the problem. Its to do with
workability.


NT

Fred wrote:
"OG" wrote in message
...


Yes, gas burned in the house has c100% efficiency at producing light+heat
(though the heat _was probably in the wrong place_). However, burning gas
in your not-so-local power station to produce electricity at +/- 50%
efficiency


Many years ago I was told the overall efficiency of generating power was in
the order of 25% taking into account generating and transmission
efficiencies. Does anyone have a link for overall electricity generation
efficiency in the UK.



Around about 55-65%
With newest kit, from heat to electrons as it were.

From (rusty) memory

Steam piston engine 5-7%
Petrol engine 15-35%
Diesel 20-40%
Gas turbine 30-50%
Steam turbine with the full condenser kit 40-65%

The maximum energy available is a function of the maxim working fluid
temperature and exhaust temperature. Condensing turbines use superheated
steam and go down to wet dripping water and water vapour.

Gas turbines use very hot working fluid (air) and are good there, but
exhausts temperatures are pretty high.


CHP that uses a gas turbine and the waste heat to heat water, and
possibly even drive a steam turbine, is really rather good.

wrote in message
oups.com...
Wait, are halogens hazardous?

They are a form of incandescent lamp and are not classed as hazardous waste.

Colin Bignell

On Sat, 8 Oct 2005 16:10:41 +0100, "Fred" wrote:


"OG" wrote in message
...


Yes, gas burned in the house has c100% efficiency at producing light+heat
(though the heat _was probably in the wrong place_). However, burning gas
in your not-so-local power station to produce electricity at +/- 50%
efficiency

Many years ago I was told the overall efficiency of generating power was in
the order of 25% taking into account generating and transmission
efficiencies. Does anyone have a link for overall electricity generation
efficiency in the UK.



Hi,

Came across this the other day which gives the grid efficiency as a
whole to be 30%:

http://www.powerwatch.org.uk/energy/graham.asp

cheers,
Pete.

wrote:
Hamie wrote:

wrote:


Both types of lamp contain toxic metal. Filaments contain thorium

Tungsten. Thorium is a radioactive metal. Not used in bulb filaments
AFAIK. Google for halogen lamp. You'll get quite a few hits from
manufacturers.


Filaments are not pure tungsten, thats the problem. Its to do with
workability.


Granted.. But I don't think the additives are thorium...

OK so the only hazard are the halogens in the bulb. But I remember
they're really reactive and when exposed will form not-so-harmful
compounds right away. A few of which we eat regularly too...

Seb

Fred wrote:

Many years ago I was told the overall efficiency of generating power was in
the order of 25% taking into account generating and transmission
efficiencies. Does anyone have a link for overall electricity generation
efficiency in the UK.



I found this, when I didn't beleive OG's figures. Seems he does know
what he's talking about.

http://www-g.eng.cam.ac.uk/mmg/envir...al/young2.html

Andy

"Andy Champ" wrote in message
...
Fred wrote:

Many years ago I was told the overall efficiency of generating power was
in the order of 25% taking into account generating and transmission
efficiencies. Does anyone have a link for overall electricity generation
efficiency in the UK.



I found this, when I didn't beleive OG's figures. Seems he does know what
he's talking about.

http://www-g.eng.cam.ac.uk/mmg/envir...al/young2.html

Andy

I've read the article and recall in the 80's the maximum efficiency from a
power station was 42%. Nevertheless the average was brought down by other
power stations which included coal fuelled stations. Ironically the older
and less efficient stations produced the cheapest electricity from a
financial point of view because the capital value was already written off.
I thought these older stations were around 30% efficiency. However the loss
of transmission was considerable to bring the overall efficiency down to
25%. I am talking of the 80's.

More recently many old coal fuelled stations have either been scrapped or
converted to oil. Also the combined-cycle generation is far more efficient.
However few articles include transmission efficiency which perhaps is a more
embarrassing issue. I see no reason to doubt the efficiency of the article
in the Pete C's post of 36%.

Fred wrote:

I thought these older stations were around 30% efficiency.

Kinda sorta plausible - a bit low, but lots of heat did go up the chimbleys,
and more in the cooling towers.

.................................................. ....... However the loss
of transmission was considerable to bring the overall efficiency down to
25%.

Firstly, if your figures mean "losses in transmission reduce efficiency from
30% at generation plant to 25% at consumption point", those aren't
'considerable' losses - one part in 6, or 17%. But even that seems
implausibly high to me: sources of loss would be conductor losses,
transformer losses, and finally 'leaks' (little bits of corana discharge).
All these losses end up as waste heat somewhere. Given the *huge* energies
involved, the latter two really can't be that big, or you'd see transformers
boiling and crops under overhead lines frazzling rather more often than you
do! The only place you could dump enough heat not to notice is in conductor
losses, as there's enough length of overhead and final-underground
conductors to get slightly warmer than ambient without spectacular effect.
However, precisely to limit resistive losses, main transmission lines run at
very high voltages - 133kV, 400kV and friends - so I find the suggestion of
'considerable' losses implausible.

So do Googles sources: one clear one, written by a
'respectable-but-biased-against-electric-generation' source, is over at
http://www.uniongas.com/business/inf...tilization.asp
which claims "The transmission efficiency of electricity is 92.6%". That's a
more plausible-to-me transmission efficiency.

And it's in line with the 'A'-level project writeup which Pete C quotes:
which, if you read it, says quite clearly "... 26 TWh energy loss in
transmission and distribution during 1998 due to unwanted heating effects in
cables and substation equipment, out of a total of 350 TWh generated. This
represents a loss of 7.4%." Sure, 7.4% of a-hell-of-a-lot is quite-a-lot,
but as a proportion, three-fortieths isn't what many of us would dignify
with the adjective 'considerable'.

Next you'll be like the fool on the radio this morning, uncritically
repeating babblings about wind turbines being 'kept running' by a backfeed
when the wind's not blowing, and claiming that this uses three times as much
energy in a year as the turbine produces when the wind is blowing... what a
pile of gonads!

Stefek

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Stefek Zaba
saying something like:

Next you'll be like the fool on the radio this morning, uncritically
repeating babblings about wind turbines being 'kept running' by a backfeed
when the wind's not blowing, and claiming that this uses three times as much
energy in a year as the turbine produces when the wind is blowing... what a
pile of gonads!

Eh? FFS, I know journalists aren't all that technically aware, as a
rule, but that takes the biscuit.
What the **** does he think it is; some sort of giant table fan?

Hmmm... there's an idea; something for the glider pilots on a calm day.
--

Dave

Stefek Zaba wrote:


Next you'll be like the fool on the radio this morning, uncritically
repeating babblings about wind turbines being 'kept running' by a backfeed
when the wind's not blowing, and claiming that this uses three times as much
energy in a year as the turbine produces when the wind is blowing... what a
pile of gonads!

The "kept running" is a load of crap but most wind generators have a
large (and some would say disproportionate) reactive power
requirements due to their use of induction generators. They can also
cause instability and additional operational problems at precisely the
time when they are required to perform.


--

Pete C wrote:

On Sat, 8 Oct 2005 16:10:41 +0100, "Fred" wrote:


"OG" wrote in message
...


Yes, gas burned in the house has c100% efficiency at producing light+heat
(though the heat _was probably in the wrong place_). However, burning gas
in your not-so-local power station to produce electricity at +/- 50%
efficiency

Many years ago I was told the overall efficiency of generating power was in
the order of 25% taking into account generating and transmission
efficiencies. Does anyone have a link for overall electricity generation
efficiency in the UK.




Hi,

Came across this the other day which gives the grid efficiency as a
whole to be 30%:

http://www.powerwatch.org.uk/energy/graham.asp


Correction. It gives the grid efficiency as 92.5%. Its the power
stations that are inefficient.


How much that matters in the case of e.g. nuclear power, is a moot point.


cheers,
Pete.

Matt wrote:

Stefek Zaba wrote:



Next you'll be like the fool on the radio this morning, uncritically
repeating babblings about wind turbines being 'kept running' by a backfeed
when the wind's not blowing, and claiming that this uses three times as much
energy in a year as the turbine produces when the wind is blowing... what a
pile of gonads!


The "kept running" is a load of crap but most wind generators have a
large (and some would say disproportionate) reactive power
requirements due to their use of induction generators. They can also
cause instability and additional operational problems at precisely the
time when they are required to perform.


I agree. More than a certain percentage of windpower is not a practical
thing.

We need power stations that can run on STORED energy - like water behund
a dam, or a lump of uranium.

Windpower is too fickle - do you want to drive a land yacht to work?

"The Natural Philosopher" wrote in message
t...
Matt wrote:

Stefek Zaba wrote:



Next you'll be like the fool on the radio this morning, uncritically
repeating babblings about wind turbines being 'kept running' by a
backfeed when the wind's not blowing, and claiming that this uses three
times as much energy in a year as the turbine produces when the wind is
blowing... what a pile of gonads!


The "kept running" is a load of crap but most wind generators have a
large (and some would say disproportionate) reactive power
requirements due to their use of induction generators. They can also
cause instability and additional operational problems at precisely the
time when they are required to perform.
I agree. More than a certain percentage of windpower is not a practical
thing.

We need power stations that can run on STORED energy - like water behund a
dam, or a lump of uranium.

Windpower is too fickle - do you want to drive a land yacht to work?

What are the current stats on the pumped storage setup at Dinorwig in terms
of operatinig efficiency and additional cost per kWh? anyone out there have
the details to hand.

On Thu, 13 Oct 2005 14:21:51 +0100, John
wrote:

What are the current stats on the pumped storage setup at Dinorwig in
terms
of operatinig efficiency and additional cost per kWh? anyone out there
have
the details to hand.

Googling for Dinorwig Efficiency throws up
http://www.ipplc.com/ipplc/investors...it/fhvisit.pdf
Probably more than you would like to know, but good stuff anyway.

John Schmitt

--
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

"John" wrote:

What are the current stats on the pumped storage setup at Dinorwig in terms
of operatinig efficiency and additional cost per kWh? anyone out there have
the details to hand.

It uses around 30-35% more power than it generates to get all the used
water back up to the top lake.

I believe they have a long term fixed contract with one of the
conventional generators for overnight pumping demand rather than buy
at the marginal price. The contracts for system support ensure pumped
storage is a profitable and stable business.

There was talk a while ago of a new pumped storage scheme being under
consideration somewhere in Scotland. There is also an "AC Battery"
that was undergoing large scale trials at a Midlands power station
site a couple of years back, not sure what the latest news on that is.


--