For the past few years I've been very intrigued about these MicroCHP boilers
that are under development, for example I can see that the so-called "BAXI
Ecogen"
should be coming to market next year:

http://www.baxi.co.uk/baxiecogen

Have any uk.d-i-y ers encountered this technology yet? There must be
hundreds of these on test out there in the field.

I'm especially interested in the noise performance. Surely these things
must produce some kind of 50/100Hz Hum!!!!!!! That would drive me nuts.

"Vortex2" wrote in message
...
For the past few years I've been very intrigued about these MicroCHP
boilers
that are under development, for example I can see that the so-called "BAXI
Ecogen"
should be coming to market next year:

http://www.baxi.co.uk/baxiecogen

Have any uk.d-i-y ers encountered this technology yet? There must be
hundreds of these on test out there in the field.

I'm especially interested in the noise performance. Surely these things
must produce some kind of 50/100Hz Hum!!!!!!! That would drive me nuts.


It said on the website "Noise less than 45dBa" which is equivalent to a man
speaking just over 12m away. Guess it depends where it is sited!


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

In article ,
"Vortex2" writes:
For the past few years I've been very intrigued about these MicroCHP boilers
that are under development, for example I can see that the so-called "BAXI
Ecogen"
should be coming to market next year:

http://www.baxi.co.uk/baxiecogen

Have any uk.d-i-y ers encountered this technology yet? There must be
hundreds of these on test out there in the field.

I'm especially interested in the noise performance. Surely these things
must produce some kind of 50/100Hz Hum!!!!!!! That would drive me nuts.

There were a couple of other products a couple of years back.
They were eventually withdrawn, believed due to reliability issues.

I think these might make sense if we were to be self-sufficient in
gas supplies for most of the boiler life. You're too late for that
now in this country. They make good sense for countries which are
still self-sufficient in gas, but then they don't need to be
concerned so much about efficiency of gas - electricity conversion,
just like we weren't. The previous micro-CHP systems couldn't produce
electricity off-grid, so there're no use in power cuts. One of them
was intending to produce a sort of add-on power pack to anable this,
but it didn't appear before the products were withdrawn.

We need to quickly move our electricty generation away from gas now,
which is no longer consistent with micro-CHP. Their time in the UK
was 10+ years ago, if they had been around at that time. It's a shame
as I like the idea.

I like this...

"In addition it is well documented that the burning of those fossil
fuels is causing a build up of greenhouse gases that is contributing
to global warming. In light of this, it makes sense to make the
best possible use of our natural resources. It is clear that we
need to produce cleaner energy, and microgeneration can help us to
address this issue at grass roots level - in our individual homes.
"
Run that by me again -- just what fuel does it use to create the
electricity ;-)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Thu, 13 Nov 2008 11:06:50 -0000 someone who may be "Vortex2"
wrote this:-

I'm especially interested in the noise performance. Surely these things
must produce some kind of 50/100Hz Hum!!!!!!! That would drive me nuts.

One of the manufacturers, Whispergen, recommend installation on a
solid floor in their instructions and recommend not installing in a
kitchen which is also used for dining.



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"Andrew Gabriel" wrote in message
...

Run that by me again -- just what fuel does it use to create the
electricity ;-)

Does it only use the waste heat from the flu to generate?

In article ,
"dennis@home" writes:


"Andrew Gabriel" wrote in message
...

Run that by me again -- just what fuel does it use to create the
electricity ;-)

Does it only use the waste heat from the flu to generate?

Well it does, but even my 6 year old condensing boiler doesn't
produce 1.1kW waste from the flue in any normal operating mode,
and then there's the matter of not being able to recover 100%
of the waste.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Andrew Gabriel" wrote in message
...

I like this...

"In addition it is well documented that the burning of those fossil
fuels is causing a build up of greenhouse gases that is contributing
to global warming. In light of this, it makes sense to make the
best possible use of our natural resources. It is clear that we
need to produce cleaner energy, and microgeneration can help us to
address this issue at grass roots level - in our individual homes.
"
Run that by me again -- just what fuel does it use to create the
electricity ;-)

Burn a 1 kW appliance on the grid and the efficiency from power station to
appliance is around 40%ish on average. Generate the 1 kW in a boiler using
very clean natural gas at 90% plus efficiency and you see the difference.
Generated at 90% plus efficiency and zero line losses as the burning
appliance is only feet away.

micoCHP still makes sense.

What makes best sense is:

1. Superinsulation,
2. Air-tightness
3. passive solar design.
4. Natural gas boiler using weather compensation control and CH zoning.

Existing homes can do Nos 1 & 2. Not fully in most cases on No. 1.

On Thu, 13 Nov 2008 11:06:50 -0000, "Vortex2"
wrote:

For the past few years I've been very intrigued about these MicroCHP boilers
that are under development, for example I can see that the so-called "BAXI
Ecogen"
should be coming to market next year:

http://www.baxi.co.uk/baxiecogen

Have any uk.d-i-y ers encountered this technology yet? There must be
hundreds of these on test out there in the field.

There were, Powergen (I think) got awfully enthusiastic about them in
2004 as potential subsidy generators and imported the Whispergen
units. After some initial reports of unreliability with many being
removed it all went very quiet and although reports were that 80,000
units had been contracted for I don't think more than a few hundred
were ever installed and the production rollout date has been one year
away for the past half decade.

The Baxi unit is I presume based upon the work they did with the now
defunct British Gas subsidiary Microgen Energy Ltd.

One major problem with MicroCHP is that it only really work well in
large houses which need a lot of heating. They are very inefficient
on short run cycles. The more you insulate your house and lower the
heat requirement the less the CHP boiler generates as they only
generate electricity parasitically on top of the heating load.
Typically the carbon savings in a reasonably well insulated house will
be below 5% and in modern houses insignificant.

I'm especially interested in the noise performance. Surely these things
must produce some kind of 50/100Hz Hum!!!!!!! That would drive me nuts.

From past performance the major problem with noise appears to be the
complete absence of it as the units seem to spend a lot of time dead.
With their low life expectancy and unreliability it might be wise to
allow others to buy the first few production batches.

"Peter Parry" wrote in message
...

From past performance the major problem with noise appears to be the
complete absence of it as the units seem to spend a lot of time dead.
With their low life expectancy and unreliability it might be wise to
allow others to buy the first few production batches.

The Microgen unit promised super reliability having a free wheeling piston
(one moving part) in the Stirling engines to generate electricity. Coils in
the piston. Designed by a specialist US company.

On Thu, 13 Nov 2008 15:18:05 -0000, "Doctor Drivel"
wrote:

"Peter Parry" wrote in message
.. .

From past performance the major problem with noise appears to be the
complete absence of it as the units seem to spend a lot of time dead.
With their low life expectancy and unreliability it might be wise to
allow others to buy the first few production batches.

The Microgen unit promised super reliability having a free wheeling piston
(one moving part) in the Stirling engines to generate electricity. Coils in
the piston. Designed by a specialist US company.

Whichever way you look at it it is a gas boiler with an added
generator. It is always going to be less reliable than the same
boiler without the added bits. What is promised, especially in terms
of reliability, in glossy brochures and what is achieved in practice
are frequently some distance apart.

So far all microCHP devices have proven to be unreliable and to have a
short service life. That isn't unexpected with any new device where
the manufacturing process is new. If you want to be at the bleeding
edge of boiler technology you will have to be willing to accept the
increased probability of failure.

"Peter Parry" wrote in message
...
On Thu, 13 Nov 2008 15:18:05 -0000, "Doctor Drivel"
wrote:

"Peter Parry" wrote in message
. ..

From past performance the major problem with noise appears to be the
complete absence of it as the units seem to spend a lot of time dead.
With their low life expectancy and unreliability it might be wise to
allow others to buy the first few production batches.

The Microgen unit promised super reliability having a free wheeling piston
(one moving part) in the Stirling engines to generate electricity. Coils
in
the piston. Designed by a specialist US company.

Whichever way you look at it it is a gas boiler with an added
generator. It is always going to be less reliable than the same
boiler without the added bits. What is promised, especially in terms
of reliability, in glossy brochures and what is achieved in practice
are frequently some distance apart.

Quality of design and quality of manufacture are very different things. I
know some poorly designed products that are well made and the opposite. The
free wheeling piston can only give reliability if made just to average
quality.

So far all microCHP devices have proven to be unreliable and to have a
short service life. That isn't unexpected with any new device where
the manufacturing process is new. If you want to be at the bleeding
edge of boiler technology you will have to be willing to accept the
increased probability of failure.

Good simple design that ensures reliability with decent manufacturing is a
great starting point. What you are saying is that Ladas were unreliable so
all cars are unreliable.

microCHP is ideal if they are subsidised in new estate developments as less
electrical infrastructure needs to be run in. The microCHP copes with
peaks. The power companies can subsidise the installations. It also gives
dispersed power generation, so less power stations needed. Millions of
homes are needed and are planned (Credit Crunch is a blip which will go
away). If these homes are all fitted with microCHP the country will
benefit, as well as the householder too.

It all makes sense. It all adds up.

On Fri, 14 Nov 2008 10:57:02 -0000, "Doctor Drivel"
wrote:

microCHP is ideal if they are subsidised in new estate developments as less
electrical infrastructure needs to be run in. The microCHP copes with
peaks. The power companies can subsidise the installations. It also gives
dispersed power generation, so less power stations needed. Millions of
homes are needed and are planned (Credit Crunch is a blip which will go
away). If these homes are all fitted with microCHP the country will
benefit, as well as the householder too.

It all makes sense. It all adds up.

A report by Advantica the research and development department spinoff
of Centrica or Transco (I can't recall which) said that MicroCHP could
probably mitigate 0.45kW of electrical load per household for eight
hours a day across the winter heating period. On a development with
200 homes that's around 350A. When the electrical supply for those
200 homes will be capable of circa 20000A then the gains from
electrical infrastructure changes are zero because a reduction of that
level has no real impact on the overall design. Scale it up to a
small eco town of 10,000 homes and it makes a difference of a few 10's
of amps at 132kV, insignificant and making no real difference to the
design of the equipment.

The conclusions that a number of studies are coming to is that CHP can
work with a heating or cooling demand in a single installation of
around the 250kW level but below that the picture is far from
conclusive. What we can be sure of is that if MicroCHP had clear
benefits for reducing carbon emissions or infrastructure spend then
the likes of EdF and Eon would have been involved in a large scale
roll out programme more than two years ago. They haven't and that is
as clear a sign as any that it doesn't offer any real benefits to the
user, the utility or the environment.


--

On Fri, 14 Nov 2008 10:57:02 -0000, "Doctor Drivel"
wrote:


"Peter Parry" wrote

Whichever way you look at it it is a gas boiler with an added
generator. It is always going to be less reliable than the same
boiler without the added bits. What is promised, especially in terms
of reliability, in glossy brochures and what is achieved in practice
are frequently some distance apart.

Quality of design and quality of manufacture are very different things. I
know some poorly designed products that are well made and the opposite.

They are usually very closely related as unless an item is well
designed for manufacture poor quality in the end product is almost
inevitable.

The free wheeling piston can only give reliability if made just to
average quality.

Just average quality is all you will ever get from mass market items -
they set the average.

If Baxi (or anyone else) make a microCHP boiler based on an existing
boiler it is _always_ going to be less reliable than the boiler only
version from the same manufacturer as the component count is going to
be higher.

So far all microCHP devices have proven to be unreliable and to have a
short service life. That isn't unexpected with any new device where
the manufacturing process is new. If you want to be at the bleeding
edge of boiler technology you will have to be willing to accept the
increased probability of failure.

Good simple design that ensures reliability with decent manufacturing is a
great starting point.

Unfortunately no one seems to have managed to do it yet.

tWhat you are saying is that Ladas were unreliable so
all cars are unreliable.

As Lada are particularly reliable - no. What I am saying is that a
considerable amount of development effort over many years by many
companies has not produced a reliable product. This indicates it
isn't an easy task and avoiding new versions might be a really good
idea until the delivery of the technology into stable manufacture
improves.

microCHP is ideal if they are subsidised in new estate developments as less
electrical infrastructure needs to be run in.

How will each house producing (on average) less than 100W/hr but only
in the winter allow for less electrical infrastructure

The microCHP copes with peaks.

As it is entirely parasitic upon the heating load how on earth can it
do that?

The power companies can subsidise the installations.

You mean their customers subsidise the installations.

It also gives
dispersed power generation, so less power stations needed.

The Holy Grail as far as greenwashers are concerned is dispersed
generation (no matter how ineffective). If you can get rid of the
National Grid you make Nuclear power generation impractical which is
their primary aim.

Millions of
homes are needed and are planned (Credit Crunch is a blip which will go
away). If these homes are all fitted with microCHP the country will
benefit, as well as the householder too.

If all these house are built to decent insulation standards with
modern and efficient boilers the heating load drops dramatically, the
waste heat is minimised and the energy to be got from parasitic
generation becomes negligible. One place Sterling Engine MicroCHP
makes no sense at all is in new builds. It may be worthwhile is in
old, large houses with very high heating loads.

It all makes sense. It all adds up.

It doesn't though.

"Peter Parry" wrote in message
...

The microCHP copes with peaks.

As it is entirely parasitic upon the
heating load how on earth can it
do that?

The CH and electricity peaks coincide.

The Holy Grail as far as greenwashers are concerned is dispersed
generation (no matter how ineffective). If you can get rid of the
National Grid you make Nuclear power generation impractical which is
their primary aim.

Which is quite a good idea.

On Sat, 15 Nov 2008 04:24:38 -0000, "Doctor Drivel"
wrote:

"Peter Parry" wrote

As it is entirely parasitic upon the
heating load how on earth can it
do that?

The CH and electricity peaks coincide.

Unfortunately they don't, they are an hour or two apart. You also
haven't explained how generating 100w/hr for a few months of the year
is going to affect infrastructure requirements?

The Holy Grail as far as greenwashers are concerned is dispersed
generation (no matter how ineffective). If you can get rid of the
National Grid you make Nuclear power generation impractical which is
their primary aim.

Which is quite a good idea.

Only if you are a neo-Luddite. The Microgen believers are the same
ones who were promoting a windmill on every roof a year or so back.

"Peter Parry" wrote in message
...
On Sat, 15 Nov 2008 04:24:38 -0000, "Doctor Drivel"
wrote:

"Peter Parry" wrote

As it is entirely parasitic upon the
heating load how on earth can it
do that?

The CH and electricity peaks coincide.

Unfortunately they don't, they are
an hour or two apart.

Government research stated so.

You also haven't explained how generating
100w/hr for a few months of the year
is going to affect infrastructure requirements?

Your estimate are way off the governments.

The Holy Grail as far as greenwashers are concerned is dispersed
generation (no matter how ineffective). If you can get rid of the
National Grid you make Nuclear power generation impractical which is
their primary aim.

Which is quite a good idea.

Only if you are a neo-Luddite.

Nonsense. You have NEVER approved any advanced ideas, always spouting the
stus quo - a Luddite. Local district CHP is a superior way to go, fired by
natural gas, using waste heat to heat buildings and less line losses.

However the anachronistic grid will remain. It is there to justify
nuclear - which is a big expensive mistake. The only reason to keep it is
using lagoons to generate electricity. The UK and Ireland can get all of
its energy, including EVs, by having about 20% of the Irish Sea made into
tidal lagoons - a 20-25 year project though, but it will be implemented in
stages. Knock on effects of bridges across say the River Seven, the Isle of
Man, N Ireland to Scotland, etc. Lagoons is being taken very seriously,
with trial planned off Swansea. Our electricity can be generated over the
horizon.

Reducing energy needs helps a lot. Having superinsulation in new and
reconditioned homes. PVs & solar panels as standard on roof tops, etc, etc.
Better urban design reducing the need for car use, etc. As high insulated
homes with solar design are being introduced, and the lagoons brought on
line the impact should be a lot quicker than people think.

Town planning and improving the building regs to superinsulation, passive
solar, etc, cots the taxpayer next to nothing. The insulation and design is
paid for by the house builders.

On Sat, 15 Nov 2008 11:13:53 -0000, "Doctor Drivel"
wrote:


"Peter Parry" wrote

Unfortunately they don't, they are
an hour or two apart.

Government research stated so.

Oh, _Government_ research. Must be right then. Would this be the
same "Government research" which assumed windmills on houses would
produce kilowatts a day of electricity per house in towns?

You also haven't explained how generating
100w/hr for a few months of the year
is going to affect infrastructure requirements?

Your estimate are way off the governments.

You are supposed to be a plumber - how much energy would be needed to
heat a 3 bedroom house built to modern building standards? How
efficient is the boiler doing the heating? The only energy left to
power the generation part of the Microgen plant is part of the 10%
waste heat from the boiler. You should be able to work out how much
that will be quite easily. When you do you will see my figures are
right (if not a bit high).

Only if you are a neo-Luddite.

Nonsense. You have NEVER approved any advanced ideas,

Which "advanced ideas"? Windmills on roofs? Generating electricity
from power which isn't there? These are not "advanced ideas" but
idiocy.

Local district CHP is a superior way to go, fired by
natural gas, using waste heat to heat buildings and less line losses.

That isn't what we are talking about.

However the anachronistic grid will remain. It is there to justify
nuclear - which is a big expensive mistake. The only reason to keep it is
using lagoons to generate electricity. The UK and Ireland can get all of
its energy, including EVs, by having about 20% of the Irish Sea made into
tidal lagoons - a 20-25 year project though, but it will be implemented in
stages.

It will?

Our electricity can be generated over the horizon.

It already is -in nuclear reactors in France.

Reducing energy needs helps a lot. Having superinsulation in new and
reconditioned homes. PVs & solar panels as standard on roof tops, etc, etc.
Better urban design reducing the need for car use, etc. As high insulated
homes with solar design are being introduced, and the lagoons brought on
line the impact should be a lot quicker than people think.

So with these highly insulated homes what is the role of the Baxi
Ecogen?

Town planning and improving the building regs to superinsulation, passive
solar, etc, cots the taxpayer next to nothing. The insulation and design is
paid for by the house builders.

You learn your economics from "Mr Browns Bedtime Economics Reader" I
presume?. Who do you think pays the house builders?

"Peter Parry" wrote in message
...
On Sat, 15 Nov 2008 11:13:53 -0000, "Doctor Drivel"
wrote:


"Peter Parry" wrote

Unfortunately they don't, they are
an hour or two apart.

Government research stated so.

Oh, _Government_ research. Must be right then.

That is what they concluded - no doubt by a privet company contracted on.

Would this be the same "Government
research" which assumed windmills on houses would
produce kilowatts a day of electricity per house in towns?

I don't know about that.

You also haven't explained how generating
100w/hr for a few months of the year
is going to affect infrastructure requirements?

Your estimate are way off the governments.

You are supposed to be a plumber

I am not a plumber. Never in million years

- how much energy would be needed to
heat a 3 bedroom house built to modern building standards? How
efficient is the boiler doing the heating? The only energy left to
power the generation part of the Microgen plant is part of the 10%
waste heat from the boiler. You should be able to work out how much
that will be quite easily. When you do you will see my figures are
right (if not a bit high).

The best of them use a thermal store to store energy. The utilities wanted
to control them remotely and start them up at specific times. This was
looked into.

Only if you are a neo-Luddite.

Nonsense. You have NEVER approved any advanced ideas,

Which "advanced ideas"?

Any.

Local district CHP is a superior way to go, fired by
natural gas, using waste heat to heat buildings and
less line losses.

That isn't what we are talking about.

It is all power generation related.

However the anachronistic grid will remain. It is there to justify
nuclear - which is a big expensive mistake. The only reason to keep it is
using lagoons to generate electricity. The UK and Ireland can get all of
its energy, including EVs, by having about 20% of the Irish Sea made into
tidal lagoons - a 20-25 year project though, but it will be implemented in
stages.

It will?

If it goes ahead.

Our electricity can be generated over the horizon.

It already is -in nuclear reactors in France.

And when they malfunction, many are on the Channel coast a few miles away
from us. Nuclear is not cheap and waste an expensive waste of time in the
long run. A front for nuclear bombs.

Reducing energy needs helps a lot. Having superinsulation in new and
reconditioned homes. PVs & solar panels as standard on roof tops, etc,
etc.
Better urban design reducing the need for car use, etc. As high insulated
homes with solar design are being introduced, and the lagoons brought on
line the impact should be a lot quicker than people think.

So with these highly insulated homes what is the role of the Baxi
Ecogen?

That is an expensive waste of time in eco homes.

Town planning and improving the building regs to superinsulation, passive
solar, etc, costs the taxpayer next to nothing. The insulation and design
is
paid for by the house builders.

You learn your economics from "Mr Browns Bedtime Economics Reader" I
presume?. Who do you think pays the house builders?

It is not via taxation. Those who benefit pay for it. Mass production
brings prices down to what we have now, or less as pre-fabbed SIP panels
will have to be used, instead of this shoddy brick an block and Paramount
board crap we see now, that leaks air like hell.

Doctor Drivel wrote:

That is what they concluded - no doubt by a privet company contracted on.

They must have been hedging their bets...

--
Andy

In message , Andy Wade
writes
Doctor Drivel wrote:

That is what they concluded - no doubt by a privet company contracted on.

They must have been hedging their bets...


vbg

--
geoff

In article ,
Doctor Drivel wrote:
Burn a 1 kW appliance on the grid and the efficiency from power station to
appliance is around 40%ish on average. Generate the 1 kW in a boiler using
very clean natural gas at 90% plus efficiency and you see the difference.
Generated at 90% plus efficiency and zero line losses as the burning
appliance is only feet away.

Given the overall efficiency is only 92% which is poor for a modern boiler
it would be fair to assume that it's the generating part which is pulling
it down in the absence of any actual figures.

But with your record on quoting efficiency it's not surprising you think
it is over 90% efficient when producing electricity.

--
*A day without sunshine is like... night.*

Dave Plowman London SW
To e-mail, change noise into sound.

"geoff" wrote in message
...
In message , Andy Wade
writes
Doctor Drivel wrote:

That is what they concluded - no doubt by a private company contracted
on.

They must have been hedging their bets...


vbg

Maxie, what does vbg mean? Is this your new secret name?

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:
Burn a 1 kW appliance on the grid and the efficiency from power station
to
appliance is around 40%ish on average. Generate the 1 kW in a boiler
using
very clean natural gas at 90% plus efficiency and you see the difference.
Generated at 90% plus efficiency and zero line losses as the burning
appliance is only feet away.

Given

You must eff off as you are a total idiotic Jocko plantpot.

On Sun, 16 Nov 2008 09:51:17 +0000 (GMT) Dave Plowman (News) wrote :
Given the overall efficiency is only 92% which is poor for a modern
boiler it would be fair to assume that it's the generating part
which is pulling it down in the absence of any actual figures.

But with your record on quoting efficiency it's not surprising you
think it is over 90% efficient when producing electricity.

Forgetting Drivel's understanding of things, where MicroCHP units
deliver is in reducing CO2, given that grid-sourced electricity is
assumed to have a CO2/kW figure of just over twice that for mains gas
(0.422 v. 0.194). The test cases we were sent when I was writing SAP
software assumed a heatower ratio of 2:1, which may or may not
realistic, but assuming this and a heat load of 20kW

Gas boiler 92%: 20 x 0.194 x 100/92 = 4.22kg CO2

CHP 90% 2:1 20 x 100/60 = 33.33kW input
33.33 x 0.194 x = 6.47kg CO2 for heating
electricity generated = 10kW
CO2 saving from displayed = 10 x 0.422 = 4.22
Net CO2 = 6.47 - 4.22 = 2.25 - 47% reduction

The docs I have read (a while back now) did emphasise that unlike
modulating gas boiler systems, Micro CHP is very sensitive to correct
sizing as you need the load to keep it running for long periods.

Note it's 2330 Melbourne time so my arithmetic is not guaranteed!

--
Tony Bryer, 'Software to build on' from Greentram
www.superbeam.co.uk www.superbeam.com www.greentram.com

In article ,
Doctor Drivel wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:
Burn a 1 kW appliance on the grid and the efficiency from power
station to appliance is around 40%ish on average. Generate the 1
kW in a boiler using very clean natural gas at 90% plus efficiency
and you see the difference. Generated at 90% plus efficiency and zero
line losses as the burning appliance is only feet away.


Given the overall efficiency is only 92% which is poor for a modern
boiler it would be fair to assume that it's the generating part which
is pulling it down in the absence of any actual figures.


You must eff off as you are a total idiotic Jocko plantpot.

Thanks for confirming you're just quoting adverts as usual and have no
idea of the principles involved.

BTW what gave you the idea of adding racial insults to your usual?

--
*Yes, I am an agent of Satan, but my duties are largely ceremonial

Dave Plowman London SW
To e-mail, change noise into sound.

In message , Doctor Drivel
writes

"geoff" wrote in message
...
In message , Andy Wade
writes
Doctor Drivel wrote:

That is what they concluded - no doubt by a private company
contracted on.

They must have been hedging their bets...


vbg

Maxie, what does vbg mean? Is this your new secret name?

If I told youi I'd have to kill you

.... and that would be uk.d-i-y's main source of entertainment gone


--
geoff

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:
Burn a 1 kW appliance on the grid and the efficiency from power
station to appliance is around 40%ish on average. Generate the 1
kW in a boiler using very clean natural gas at 90% plus efficiency
and you see the difference. Generated at 90% plus efficiency and zero
line losses as the burning appliance is only feet away.


Given the overall efficiency is only 92% which is poor for a modern
boiler it would be fair to assume that it's the generating part which
is pulling it down in the absence of any actual figures.

You must eff off as you are a total idiotic Jocko plantpot.

Thanks

You must eff off as you are a total idiotic Jocko plantpot.

"Tony Bryer" wrote in message
...
On Sun, 16 Nov 2008 09:51:17 +0000 (GMT) Dave Plowman (News) wrote :
Given the overall efficiency is only 92% which is poor for a modern
boiler it would be fair to assume that it's the generating part
which is pulling it down in the absence of any actual figures.

But with your record on quoting efficiency it's not surprising you
think it is over 90% efficient when producing electricity.

Forgetting Drivel's understanding of things,

Which is much superior to yours.

In article ,
Tony Bryer writes:
On Sun, 16 Nov 2008 09:51:17 +0000 (GMT) Dave Plowman (News) wrote :
Given the overall efficiency is only 92% which is poor for a modern
boiler it would be fair to assume that it's the generating part
which is pulling it down in the absence of any actual figures.

But with your record on quoting efficiency it's not surprising you
think it is over 90% efficient when producing electricity.

Forgetting Drivel's understanding of things, where MicroCHP units
deliver is in reducing CO2, given that grid-sourced electricity is
assumed to have a CO2/kW figure of just over twice that for mains gas
(0.422 v. 0.194). The test cases we were sent when I was writing SAP
software assumed a heatower ratio of 2:1, which may or may not
realistic, but assuming this and a heat load of 20kW

Gas boiler 92%: 20 x 0.194 x 100/92 = 4.22kg CO2

CHP 90% 2:1 20 x 100/60 = 33.33kW input
33.33 x 0.194 x = 6.47kg CO2 for heating
electricity generated = 10kW

These units are 1.1kW max, just using waste heat.

CO2 saving from displayed = 10 x 0.422 = 4.22
Net CO2 = 6.47 - 4.22 = 2.25 - 47% reduction

The docs I have read (a while back now) did emphasise that unlike
modulating gas boiler systems, Micro CHP is very sensitive to correct
sizing as you need the load to keep it running for long periods.

That's what I imagine to be a big failing. Considering a house
I've done detailed heatloss calculations for, 3 bedroom, semi or
end-terrace, built 1909 (9" brick walls), only insulation added
since built was double glazing (before April 2002) and 4" loft
insulation, i.e. probably below average insulation for UK
housing stock. Calculated heat loss at -3C is 11kW. (Based on
subsequent experience running the system, I suspect this was an
over-estimate. At a more typical temperature of 5C, heat loss is
barely 7kW, which is what the boiler will modulate down to.
There's nowhere near enough wasted energy to run a waste energy
generator at this level. The only time the boiler runs at 25kW
(where it could run a stirling enging) is for about a minute
when it's first switched if the radiators are stone cold.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"geoff" wrote in message
...
In message , Doctor Drivel
writes

"geoff" wrote in message
...
In message , Andy Wade
writes
Doctor Drivel wrote:

That is what they concluded - no doubt by a private company contracted
on.

They must have been hedging their bets...

vbg

Maxie, what does vbg mean? Is this your new secret name?

If I told youi I'd have to kill you

My God!!!! You are a secret agent Maxie. Fantastic!!!!

...James Bond, oh yes you are
...Maxie drives a big flash car
...He has guns inside the light
...He shoots the Ruskies to our delight

...A suave man to no avail
...shaken not stired he has his brown ale

"Andrew Gabriel" wrote in message
...

The only time the boiler runs at 25kW
(where it could run a stirling enging) is for about a minute
when it's first switched if the radiators are stone cold.

They were meant to be combis, where they run at full belt when the taps are
on.

In article ,
"Doctor Drivel" writes:

"Andrew Gabriel" wrote in message
...

The only time the boiler runs at 25kW
(where it could run a stirling enging) is for about a minute
when it's first switched if the radiators are stone cold.

They were meant to be combis, where they run at full belt when the taps are
on.

So how long do you keep your hot water running?
(For the purpose of this question, you can discount
any burst pipework;-)

Like I said, useless.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Andrew Gabriel" wrote in message
...
In article ,
"Doctor Drivel" writes:

"Andrew Gabriel" wrote in message
...

The only time the boiler runs at 25kW
(where it could run a stirling enging) is for about a minute
when it's first switched if the radiators are stone cold.

About a minute? Look again.

They were meant to be combis, where
they run at full belt when the taps are
on.

So how long do you keep your hot water running?
(For the purpose of this question, you can discount
any burst pipework;-)

It is "seasonal" performance that matters. In summer they will still be
producing electricity (combi or not) and pumping that into the grid, which
will be used by local consumers with less line losses and hence higher
efficiencies.

First thing in the morning when the combis are at full belt in heating
before modulating down, and also full belt in DHW, is also the time when
there is also high electricity demand. The peak usgage of both coincides.
microCHP will level off the peaks of electricity demand. microCHP makes
sense in new housing estates. If millions are installed then they will make
a significant impact. It is clear not so many new power stations would be
built, and probably eliminate the nuclear option.

Like I said, useless.

You need to think it through.

On Mon, 17 Nov 2008 11:40:38 -0000 Doctor Drivel wrote :
First thing in the morning when the combis are at full belt in
heating before modulating down, and also full belt in DHW, is
also the time when there is also high electricity demand. The
peak usgage of both coincides. microCHP will level off the peaks
of electricity demand. microCHP makes sense in new housing
estates.

The example you give is precisely where it makes no sense. If you
size it for DHW it will be grossly oversized for heating; if you
size it for space heating you then need something else for DHW.

A (non-micro) CHP plant possibly makes sense where you have an
extended need for heat and power, e.g. a municipal swimming pool.

--
Tony Bryer, 'Software to build on' from Greentram
www.superbeam.co.uk www.superbeam.com www.greentram.com

In article ,
Tony Bryer wrote:
On Mon, 17 Nov 2008 11:40:38 -0000 Doctor Drivel wrote :
First thing in the morning when the combis are at full belt in
heating before modulating down, and also full belt in DHW, is
also the time when there is also high electricity demand. The
peak usgage of both coincides. microCHP will level off the peaks
of electricity demand. microCHP makes sense in new housing
estates.

The example you give is precisely where it makes no sense. If you
size it for DHW it will be grossly oversized for heating; if you
size it for space heating you then need something else for DHW.

It really makes you wonder about dribbles claims to be a heating
engineer...

A (non-micro) CHP plant possibly makes sense where you have an
extended need for heat and power, e.g. a municipal swimming pool.

My guess is maintenance and repair costs would well exceed any saving in
electricity.

--
*Confession is good for the soul, but bad for your career.

Dave Plowman London SW
To e-mail, change noise into sound.