Re: Can energy be produced with no pollution by using less of it?

The tone of your question and the particular example that you chose, would 
suggest that you are just trying to be picky for pickiness sake, but since 
physics professors live for pickiness, I'll respond.

If you had read Brendon's question that prompted my response you would 
alreay realize that he, and therefore I, were both referring to the 
production of electrical energy from limited fossil fuel resources.  If 
you read a little farther, you would realize that I was answering a 
question from a middle school student and not a college student.  I expect 
his level of physics knowledge is somwhat different from yours.  If you 
check the dates, you will realize that this question arose during the time 
when the western United States was facing rolling blackouts due to 
insufficient generating capacity.  If I were being truly picky, I suppose 
that I should have said that additional capacity could be produced with no 
additional pollution or depletion of resources, simply by using less 
energy.  

As is clear to any physicist, but often not clear to physics students, 
there is a difference in the usage of the word energy by physicists and by 
the general populace.  Energy, as the physicists use it, can not be created 
 by any process.  Even fission or fusion which seem to create energy out of 
mass are simply converting energy from one stored form to another form.  
E=mc^2 can simply be viewed as a definition of mass as a form of potential 
energy.  Energy as the ordinary person uses it, usually means the 
electrical potential energy supplied to my sockets from a power plant where 
it is generated by the conversion of some form of stored chemical or 
physical potential energy.

The creation of the latter form of energy in our society involves both 
scientific and economic principles.  Once the capacity of power plants to 
produce electrical potential is exceeded by demand, then "new" sources of 
electrical potential energy must be created to meet the demand.  One way to 
do this is to build new power plants.  Conventional fossil fuels are the 
least expensive option, but do the most environmental damage and are a 
severely limited resource.  Nuclear fuels are also an option, but also come 
with environmental implications, mostly involving processing and disposal 
of the fuel.  The only way to meet increased demand for electrical 
potential energy in some parts of the system without polluting the earth 
is to reduce demand in other parts of the system through conservation.  
Economically, as far as the power company is concerned, electrical 
potential energy made available by conservation is indistinguishable from 
such energy made available by burning fossil fuels.  Although the physics 
student can argue that energy is never "created," any reasonable person 
will accept that conservation by one person "creates" the potential for 
someone else to use that energy, and potential is all the electric grid 
supplies us with anyway.  Utility managers have found that conservation is 
such an effective way to create potential for extra users that they will 
often pay for conservation themselves.  The cost of low wattage bulbs and 
energy conserving appliances of often less per killowatt hour than the cost 
of new generating plants.

Your refrain from using fossil fuels for several days, for example, plays a 
small but non-trivial role in reducing the national demand and making the 
supply more available to others.  This is not reflected in great pools of 
gasoline sitting around waiting to be sopped up, or in some increase in 
the cosmic energy budget, but in economic factors such as the rapidly 
falling price of gasoline here in the Northeast.  

The use of language is critically important to scientists and pickiness 
is justified as it affects clarity.  Nevertheless, just as scientists would 
wish for the average person to use scientifically meaningful words with 
care, scientists must also be respectful of ordinary usages if we are not 
to be sidelined as irrelevant "ivory tower eggheads."  In a different 
example, the chemists' definition of organic would include the synthetic 
hydrocarbon-based pesticides that are anathema to the person who calls 
herself an organic farmer.  Being able to hold both these definitons in 
mind at one time and weigh their usages marks a person as intelligent, 
being slavishly devoted to one of them and unable to accept the other marks 
that person as a pedant.

Some of my best friends are pedants,

David Smith, Ph.D.
Associate Professor of Geology, Environmental Science, & Physics
La Salle University, Philadelphia, PA