On 2011/01/13, at 10:58 , Michael GLASS wrote:
> Dear People,
> <snip>
> 3 As a result, power consumption on larger screen sizes is far higher than
> might be anticipated by looking at the screen size. For example, a 15 inch
> computer monitor is very nearly a 33% larger than a 13 inch model whereas 15
> is just over 15% larger than 13.
>
> 4 With the issue of global warming, the power consumption of larger screens
> is a matter of increasing concern.
> <snip>
> Michael Glass
Dear Michael,
I think that you have confused "power consumption" when you mean "energy
consumption". Here is a note that I sent to my member of Parliament when he,
likewise, used the word "power" when he meant "energy".
##
Did they mean energy or did they mean power?
When politicians and journalists speak about energy or power it invariably
becomes clear that they have no idea what these words actually mean, when they
use these words interchangeably. And if I hear this I immediately lose
confidence in their ability to understand the basic reality that underpins
globally important concepts such as peak oil, the greenhouse effect, global
warming, and climate change. When discussing these issues we are really
discussing energy and the rate it flows into and out of our environment; that
is we are discussing energy ('the ability to do work') and power ('the rate of
using energy').
Many politicians and journalists clearly don't know that energy means being
able to do something and power is a measure of how quickly the energy is used.
One way of understanding the difference between energy and power is to compare
them with distance and speed.
If you travel the 1000 kilometres from Sydney to Melbourne in 10 hours
travelling time, you know that your average speed is 100 kilometres per hour
(km/h). If you do this in a Ferrari with a top speed of 350 km/h you will still
average 100 km/h unless you break some, or all, of the speed limits on the way.
The Ferrari marketers routinely publicise the top speed even though they know
that no-one can legally travel at anywhere near this speed on public roads.
Now let us suppose that in my business I receive regular deliveries that are
charged as so many cents per kilometre. It does not matter to me how fast the
driver travels to my address. He could deliver my parcels in a truck at 80 km/h
or in a Ferrari at 350 km/h. I am buying distance, not speed. Most of us know
that distance and speed are quite different concepts.
Energy and power are also quite different concepts. Energy gives us the ability
to do things and power is the rate (speed) we do them. Energy is measured in
joules and power is measured in watts where the word, watt, simply means joule
per second; the word 'watt' is just a short way of writing 'joule per second'.
Suppose you turn on a 100 watt light bulb for 10 seconds to light your way to
the toilet. This means that you have just bought 1000 joules of energy from
your electrical energy supplier The 100 watt light bulb uses energy at a rate
of 100 joules per second (J/s).
If you replace the 100 watt light bulb with a 20 watt light bulb (using energy
at 20 joules per second), you will now use only 200 joules of energy to light
your way to the toilet instead of the 1000 joules of energy you used before.
Your cost has gone down by 80 % and your production of greenhouse gases has
also dropped dramatically because you are using less energy. You are still
buying and using energy but you are now using it more slowly.
When you get your energy bill you are paying for the energy you used, not how
fast you used it. You are buying energy, not power. You did not – and you
cannot – use power for lighting your way to the toilet. Power is always simply
a measure of how fast you use the energy.
As another example, if you boil an electric jug to make four cups of coffee you
will need about 350 kilojoules of energy that you buy from your electrical
energy provider. If you want to do this quickly you need an electric element in
your jug that uses energy faster – with more power. A 1000 watt jug will boil
this jug in about 6 minutes and a 2000 watt jug will take about 3 minutes.
Few people are aware that energy and power are quite different physical things.
They don't know that energy is the ability to do things and that power is a
measure of how fast you use the energy.
When selling electrical energy plans to politicians and the public, the
electrical engineers who are doing the marketing actively encourage this
ignorance. Like the Ferrari marketers these electrical marketing people choose
to sell by referring to the top power rating (equivalent to speed) that will
rarely, if ever, be achieved. For example TRUenergy has gained political
approval to build a solar energy converter near Mildura by describing it as a
'345 gigawatt generator'.
Maybe some day ("Solar energy will not come in overnight"), when the Sun is
shining brightly, when there are no clouds, when there is no dust in the desert
air, when all of the solar collectors have just been cleaned, and when the
temperature is at an optimum for solar collector operation, this installation
might occasionally be able in a single second to convert 345 gigajoules of
solar energy into 345 gigajoules of electrical energy that TRUenergy can then
sell.
However, two things are clear: TRUenergy will not be generating power as they
are an energy converting company and TRUenergy will never sell power because
what they do is convert energy from one form to another and then sell that
energy to us in the form of electrical energy. We can then use that energy
around the house, and we can choose the power to use the energy we buy quickly
or slowly.
Unfortunately, the marketing engineers have had considerable success with their
obfuscation. They have been able to convince many, perhaps most, in politics
and the media that the two concepts of energy and power are synonymous and
therefore these words can be used interchangeably. This leads to some odd
constructions that are routinely used by politicians, reporters, and editors.
I have already mentioned 'power generation', which cannot be done, but which
sounds rather godlike; and the idea of selling power, which is equivalent to a
car salesman asking, 'How would you like to buy some 80 kilometres per hour –
it's on special this week.'
When you understand that energy and power are different physical realities, you
begin to question whether many word constructions actually have any basis in
reality. Consider these examples from newspapers where the word, power, has
incorrectly replaced the correct word, energy: electric power, power assets,
power bill, power blackouts, power consortiums, power supply, power companies,
power stations, reducing power demand, saving power, solar power, steam power,
wind power, and so on. (These are correctly written as electric energy, energy
assets, energy bill, energy blackouts, energy consortiums, energy supply,
energy companies, energy stations, reducing energy demand, saving energy, solar
energy, steam energy, wind energy, and so on.)
In all of these the word power is hopelessly confused when writers don't
realise that power only refers to the physical reality of how fast energy is
used. Specifically, power cannot be generated, it cannot be bought, and it
cannot be sold.
However, the word power can be, and often is, used outside this purely physical
reality. Let me construct a mythical story using only words and phrases that I
have taken directly from politicians and the daily media:
The politician got his big break into a power position when his party came to
power at the last election. As the only engineer in the party in power, the
powerful leadership team appointed him as Minister for Power. The Minister for
Power was a large powerful man who exuded physical power when he was seen doing
his power walk in the corridors of power.
As Minister for Power he enjoyed having the power to supply or to deny power to
the community. One of the responsibilities was to manage power stations from
their initial power up, maintaining power supplies during their lives of power
production, and to depower each power station at the end of it power producing
life. He felt that among the various administrative power positions in this
powerful government, he alone had any power over real power supplies.
As a practical matter I know that I have to pause whenever I read or hear
either of the words, energy or power, anywhere in the media. I try to determine
whether the journalist or politician knows that energy and power are different
and distinct physical realities, and I try to guess what the writer and the
editors might mean by energy or power according to the context. This makes for
rather stop-start, and very slow, newspaper reading, so mostly I just stop
reading or listening as soon as I determine that the politician or the
journalist doesn't know what they are talking about.
Unfortunately, the marketing engineers have had considerable success with their
obfuscation over the last 100 years or so by regularly interchanging the words,
energy and power, and by pretending to sell energy in the cobbled together
words, kilowatt and hour as kilowatt-hour that give the illusion of selling
power. The marketing engineers have been able to convince many, perhaps most,
in politics and the media that the two concepts of energy and power are
synonymous and therefore the two words, energy and power, can be used
interchangeably.
In the meantime gas companies, who also sell energy to the public, use the
technically accurate and precise measuring units, joules, kilojoules,
megajoules etc.
Finally, I have to say that I doubt that our politicians can begin to fully
understand peak oil, the greenhouse effect, global warming, and climate change
until they are informed by experts who understand the difference between the
physical realities of energy and power and not from articles written by
journalists who are deluded by spin from companies who hope to gain from
misinformation and obfuscation.
I doesn't help if lobbyists, such as from the ACF, misuse the words energy and
power when communicating with politicians or with the public. I'm sorry to be
so blunt but I do so in the interests of clearer communication on what are
vital global issues.
##
Cheers,
Pat Naughtin LCAMS
Author of the ebook, Metrication Leaders Guide, see
http://metricationmatters.com/MetricationLeadersGuideInfo.html
Hear Pat speak at: http://www.youtube.com/watch?v=_lshRAPvPZY
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008
Metric system consultant, writer, and speaker, Pat Naughtin, has helped
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