As a society and individually, we use energy every moment of our lives to improve our quality of life. Energy 101 will develop the big picture and connect the details of our energy use, technology, infrastructure, impact, and future.
Energy Conversion
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Del curso dictado por Georgia Institute of Technology
Energy 101: The Big Picture
441 calificaciones
De la lección
Energy Conversion
This module concentrates on topics in Energy Conversion
Conoce a los instructores
Dr. Sam SheltonProfessor Emeritus
Woodruff School of Mechanical Engineering
Dr. Richard A. SimmonsSenior Research Engineer & Fellow
Strategic Energy Institute
Hello. In this module of Energy 101 we're
going to talk about the energy conversion.
We've talked about the ways that society uses energy and the, and where we get
that energy from. We'll talk about why, why society and
where society uses it. We'll talk about where the natural forms
of that energy comes from, because we can't create energy out of
nothing. And now, we're going to talk about energy
conversion that converts the energy from the natural forms that we find it, like
coal, and natural gas, and nuclear, and oil, and wind, and solar, and hydro, and
all biomass, and all the natural forms that we find this energy in.
But it doesn't do us any good unless we can convert it from the form that we find
it in its natural state to a form the society wants it.
So that's where we're, where we're headed on this module.
let's break that conversion process down a little bit further.
on the left here, we have the, again, the natural forms of energy,
that we find them in the natural state. And we have the society uses that we, the
he, the, have them, that we want to make like more comfortable.
Heat and work and chemical energy, cooling energy for, and electricity.
But now let's talk about the energy conversion process to convert those.
The devices, the infrastructure, the equipment that's necessary to convert
energy from one form to the other are fossil fuel power plants like coal power,
power plants, natural gas power plants, nuclear power plants.
Nuclear is not fossil, but moving down to nuclear.
the auto engine converts gasoline that comes directly from oil.
And the diesel engine for, takes diesel fuel that comes directly from oil on
essentially a one to one energy basis, and drives a car for transportation which
is in the work form. Natural gas furnace heats our homes, air
conditioning keeps our homes cool. Pumps pump the water from the wells into
our bathrooms and our kitchens, so, and take showers, so we don't have to haul it
by, with buckets. the refrigeration system preserves our
food so we don't have to shop everyday for fresh food.
And then the light bulb converts electricity to light which the
electricity of course has to be, is, of course produced from from the power
plants. So these are the conversion processes and
the equipment. One thing that I'll note here.
That we can't just change getting energy from oil, gas or coal for instance to
produce heat or electicity that we want in society without changing the equipment
that's necessary to make the conversion. And that, that infrastructure is a huge
investment, it's a huge economic investment.
So that's one of the problems with going to renewables from the, from coal, for
instance, or nuclear, is because we have to, to replace the infrastructure that
we're currently using to convert coal or natural gas to, the forms of energy we
wanted, to a totally new, conversion process requires all new equipment and
these, these this is like trillions of dollars in order to do that on a national
basis. just one note that we need to be aware of
there but these, that conversion process is what we're going to focus on now.
the, the conversion process has some natural laws that govern what can be done
and what we can't do. And this isn't a science course, and I'm not a scientist,
and the philosopher to talk about, why the laws are the way they are. They're
natural laws that, the way, the the Earth is made up.
gravity pulls down, not up. We don't debate why it doesn't pull up
why it pushes down. same way with the natural laws of energy
conversion. And those natural laws are divided into 2
primary laws. The first law of energy conversion most,
many times called the first law of thermodynamics and the second law which
we'll get to in just a minute. So in this module we just want to
introduce these concepts but the first law of thermodynamics or the way nature
makes us operate is that energy is conserved.
As we've already commented we can't create nor destroy energy.
Total energy cannot be created or destroyed, and so we can't produce it
from nothing. And yet, too many times our intuition
tells us, well why can't we get energy from all of the molecules bouncing around
in the atmosphere for instance. But it just doesn't allow us to do the
that even. but the first law of thermodynamics is,
we can only, we cannot produce energy, we can only convert it from one form to the
other. that's a major issue, so when we talk
about breakthroughs in energy technology. It's merely a breakthrough to convert
energy from a new form that we can find it, like solar energy or wind energy,
into a form that we want it. we haven't discovered a new form of
energy. That wind energy and solar energy was
always there. We merely developed the technology and the infrastructure to
convert it. trying to give you a little bit of
intuition on this. The analogy that our intuition, probably
a little more consistent on is total mass cannot be created or destroyed.
You can't just annihilate energy, mass, nor can you create mass.
We can have a chemical reaction and change one changed mass from one type of
form to another. But the total mass, stays the same.
You can take two components and react them, but the resulting mass is going to
be the sum of the two that you started out with.
So that's the first law to thumb dynamics, which makes a little bit of
intuitive sense, if we think about it from that's similar to the mass of
conservation. The second law of thermodynamics is even
less intuitive than the first might be. And, it really says all forms of energy
do not have equal value. whereas a kilogram or a pound of mass is
equal to another kilogram or pound of mass, they may not have equal value.
Well, the 2nd law of thermodynamics, or the 2nd law of energy conversion has a
similar statement about energy. There, forms of energy have, some have
higher value than another form and that's just the way nature has built the
universe. And we can't get around it.
We've known this for 150 years And there's no, no new discovery.
First law of thermodynamics is 150 years old.
The second law is about the same. And so we have to operate with those laws
of physics. but as an example, work energy or
electrical energy has a higher value than Than warm air or hot air energy.
You may have an equal amount of energy in each, but they aren't of equal value.
Again, taking an analogy from mass, is that even though a pound of gold is equal
in mass to a pound of silver They are not of equal value from lot many
perspectives. And you can't just change 100% of
kilogram of silver and one kilogram of gold.That just doesn't work that way.
So, those are the two basic laws that control our energy conversion from the
natural form that we want it, that we find it to these forms that society wants
it, and we'll delve into those a little deeper in the next two modules.
Thank you.
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