victorian/edwardian houses or new houses?

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I thought that the natural gas accessible to the UK was not all that much any more.

a
It would surprise me if they ever got that much wind power installed.

I do indeed understand how they work. The term "efficiency per square foot" is nonsense. Do you mean to tell me that if a panel has an efficiency of 1% per square foot, the installation of, say, 200 sq. ft of panel would have an efficiency of 200%?

they
That has been the situation for a couple of decades. It is not politics, but physics and engineering which may, or may not, get the economics right.

Actually I have my doubts about them too.
Franz
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The North sea is still full of it and we also import the stuff from Russia.

use
power,
There is a mass installation programme right now, with much off it just off-shore, out of sight and in direct line of wind.
Britain is the windiest country in Europe.

No. Just that other panels, such as Thermomax, are far higher per squ foot area than a normal cheap flat plate.

The technology and engineering is there, and it is improving by the month. That is not the problem at all. It is educating the people about the new technology and the will to push it through.

complicated
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much
Russia.
Stirling
are
So with a large area of Thermolux you might get to 200% more easily than with other panels? Please, please understand that there is no such concept as "efficiency per square foot" in either engineering or in physics. Efficiency is usually simply the ratio between the output power and the input power of a system.
[snip]
Franz
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I forget the figures, but they are much more efficient and generate hot water at low solar levels.

Output per squ foot then. A sq foot of Thermomax is ratio between input and output, which is much more than the input output ratio of a squ foot of flat panel. This means in a given area the Thermoxmax gives me more hot water per square foot, which mean per square foot of area the Thermomax is more efficient. This is a moot point.
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The figure itself is irrelevant, if it is a figure for "efficiency per square foot". Any value, whatever it may be, will, according to you, be able to yield more power out than is put in, if you employ a large enough area.

per
system.
That is an entirely different can of fish.

No. a square foot is not a ratio of any kind whatsoever. It is an area.
which is much more than the input output ratio of a squ foot of flat

You appear to be trying to say that any given area of Thermomax will yield a larger power output than the same area of what you call "flat panel". If my guess is right, I will have no reason to disagree with you.

Yes.
No. The efficiency is not proportional to the area. If the efficiency per square foot of Thermomax is, let us say, 30% per square foot, then a setup with, say, 20 square feet, would be 600%, which would violate the first law of thermodynamics.

The mootness will immediately disappear into thin air if you would stop talking about "efficiency per square foot" and just stick to the shorter phrase "efficiency", without conjoining the "per square foot".
Franz
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Franz Heymann wrote:

Actually that is not totally so. Efficency is a term that can be applied to more things than power.
For example, one could define the efficiency of a roof in terms of the amount of water that runs off versus the total amount that falls on it.
One can define an efficient business as one that has the highest sales value, or margin value, per employee.
Efficiency is a measure of the efficacy against a theoretically perfect system, of something doing the job it is designed to do. As normally measured by how much it produces of the desired output versus how much input it needs.
If we for example take solar energy, it is not menaingful to say that e.g. civering every roof in lonbdon with a .3% efficient solar panel is inefficient, if the cost of so doing would actually be less than building and running an equivalent power station over the same . timescales.
One could argue that in terms of various resources one or the other is more efficient.
The power station takes up less space, but uses more fossil fuel. The electric panel is inefficient in overall thermodynamic terms, but maybe more efficient in the actual use of sunlight, since we don't have to wait a couple of million years for the trees to turn back into oil...The power station has far less labour content involved, but perhaps uses more materials.
uppose fo an instant that we cracked fusion power. Who cares about efficiency, since the actual waste products - helium and heat - are totally insignificant in a global context. At that point electcity would become the cheapest form of energy, subject to no taxes at all probably, and we would all be driving electric cars, and heating our houses electrically, immediately :-)

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per
system.
<snip>
quite.
but Efficiency _per square foot_????
if
efficiency = power of panel out per square metre / power put into panel per square metre
then the area terms disappear.
-- Richard Sampson
email me at richard at olifant d-ot co do-t uk
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than
usually
per
They don't. They are clearly there. Look above, you wrote it..."per square metre", make that per square foot.
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than
usually
per
Quite. And you don't even have to measure the area to deduce the efficiency.
Franz
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per
system.
That is the beginning of a circular argument.

Thanks for the homily.
I agree that in general usage, "efficiecy" is bandied around with gay abandon. However, the discussion about solar panels was a scientific/engineering one. To talk about "efficiency per unit area" in such a context is pure nonsense.
In engineering and scientific parlance, efficiency is to do *only* with energy and power. The efficiency of a sytem for converting energy from one form to another is uniquely defined as the ratio between the output and the input power. Since energy is simply the integral of power with respect to time, the same definition for efficiency will then also determine the ratio between the input and the output energies.
Franz
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than
usually
What balls!
I reserve a part of a roof of 20ft x 10ft, 200 squ foot. I put in flat plate collectors, I get n volume of solar heated hot water on a certain isolation at a certain time of year. I put in the same 200 squ foot Thermomax solar collectors. I get n x 2 volume of hot water on the same isolation and certain time of year. For each squ foot of roof the Themomax is 100% more efficient. Is that clear?
I could use 400 squ foot of flat plate collector on the roof, twice the area, and produce the same volume of solar hot water as the Thermomax solar collectors which takes up half as much square footage.
The area is "very" important in this instant. Is that clear?
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IMM wrote:

Yes, but efficiency is independent of that IMM.
Thats tantamount to saying a 5oKw boiler is twice as efficient as a 25Jw one.
Because it takes up the same floor space.

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applied
oil...The
would
probably,
Themomax
solar
It is not. Solar collectors produce hot water. Some produce more than others for the same area, hence more efficient for a given area.
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the
No.
Efficiency is the ratio of converted power out to power in .
The area doesn't come into it.
Are you saying that for a given solar collector, if you have two installations of _the identical model_ but with installation X having a 1sq m area but Y having a 2 sq m area, then because installation Y has an output that is twice that of installation X it is necessarily twice as efficient?
No?
Well, that is the implication of quoting a bogus specification like "efficiency per square metre".
Or to put it another way. I have installation X which is 1 sq m and I can calculate it's efficiency is 60%. The efficiency of installation Y is still 60%. It has twice the input power, but also twice the output power.
-- Richard Sampson
email me at richard at olifant d-ot co do-t uk
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Thermomax
25Jw
In this case it does. Area is the most important factor as it is limited on a roof. Solar panel X can be more efficient (ratio of converted power out to power in) than panel Y. But panel X may take up four times the area of panel Y. It means eff all if the area is not taken into account. For a given area which is the most efficient? Area, area, area.
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twice
than
on
out
Also, with solar panels the input doesn't really matter as you don't pay for it. The output per square foot, or metre (hot water generated), is what matters. The efficiency of a boiler comes into the "ratio of converted power out to power in", and is important as you pay for the fuel.
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a
limited
of
a
for
Technically Richard's right. You keep switching your definitions.
Quote: Solar panel X can be more efficient (ratio of converted power out to power in) than panel Y <snip> For a given area which is the most efficient? Answer: Obviously panel X. You said so yourself.
Quote: panel X may take up four times the area of panel Y OK. So you could swap each panel X for four Y's in the same area. This effectively gives you a large panel Y with the same area as a panel X and all that matters is the relative efficiency.
But practically you are right as well - area is very important assuming the area cannot be tiled by panels because it is too small. But, the efficiency is still the same. Surely all you have to do is:
1. For each panel type, work out how many (if any) you can fit on the roof. 2. Multiply by the efficiency
Whichever gets the highest score will give you the most energy output from your roof.
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[snip]

[IMM says:]

You do. You talk about "efficiency per square foot" and in the next line you refuse to multiply the efficiency per sq ft by the area to obtain the resultant efficiency.
[snip]
Franz
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