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Home Improvements!

Course video 86 of 130

We finish up renewables this week by discussing those coming from water – hydropower, geothermal, waves, and tides. You will even see Prof. Ruzic walking on water. Then, the world of the nucleus is opened up to you. What is radioactivity and how much should be feared? What is the basis for fission and how does a power plant differ from an atomic bomb? “How Things Work” looks at the visual world – from why the sky is blue to how a 3D IMAX movie system makes it seem like you are really there.

For a sample of what this course will include, see the video "Energy, Environment, and Everyday Life MOOC with University of Illinois Professor David Ruzic" - http://go.citl.illinois.edu/Energy-MOOC This course teaches you everything you need to know about energy, the environment, and at least a number of things in everyday life. It starts by talking about energy itself and where it comes from. This includes how much we have, who has it, who uses it, and what that all means. The video clips are produced in a fast-paced multimedia format during which Professor Ruzic throws in fun and demonstrations. There are multiple-choice questions to check your understanding and some more in-depth exercises to guide you deeper into the subject. After explaining the main things we use energy for – our cars and electronics! – fossil fuels are examined in detail. Want to really learn about fracking or pipelines? Watch these segments. The environmental effects of fossil fuels are taught as well. Global warming, acid rain, and geoengineering all are in this part of the course. Part of their solution is too. Renewables follow, with clips on solar, wind, hydro, geothermal, biofuels, etc. You’ll even see Professor Ruzic in a corn field and in the middle of a stream showing how you could dam it up. Finally, nuclear power is taught in detail – how it really works and what happens when it doesn’t work, as in Three Mile Island, Chernobyl, and Fukushima, as well as how we are making it today, which is shown here without political preconceptions. In this course, economics takes center stage. People will ultimately do whatever costs the least, so energy policy is most effective when it is targeted at the user’s wallet. Throughout the course there are 24 segments on “How Things Work." These guides to everyday life are tremendously varied, covering everything from fireworks to making beer to what happens backstage at a theater. The course is designed to be enjoyable as well as informative. We hope you will take a look!

Visualiser le programme de cours

Enseigné par

David N. Ruzic
Abel Bliss Professor

Transcription

[SOUND]

If you look at energy statistics over

the last 40, 50 years, you'll see, generally, an increase.

And the world is certainly continuing that.

There are bumps here and there, as we have discussed, for great depression,

world wars, revolutions, the oil embargos.

But, generally, world energy use has gone up and so

has the productivity, the gross national products of the countries of the world.

In the United States, a very interesting things has occurred.

Our energy use has actually stayed very flat,

yet our productivity, our gross domestic product,

the combined effort of our goods and services has increased.

This next graphic really illustrates that point.

Here is energy consumption per real dollar of GDP, that means adjusted for inflation.

And you can see on the green curve, that this number has gone down from something

over 15 in 1950, today, probably under 10,

practically cut in half in this intervening 50, 60 years.

So this graph is energy use per gross domestic product.

If we show the graph of just our gross domestic product,

it's growing up and our energy totally use has gone flat.

How is this happen?

And could the rest of the world also become as efficient?

But first I should tell you that the graph of something like this for

Europe looks very similar.

And even in many of the developing world countries, they have become

a bit more efficient per GDP that they've produced as time as gone on.

The real key is to understand where can we have gains of efficiency so

that we can use energy wiser.

So a key in understanding this is to see where have these gains and

efficiencies come from?

Where have we used energy more efficiently?

And that may point us to places where we might be able to use it even more

efficiently in the future.

So we have gains from doing better, I'll call it green architecture.

Right, improving installation.

Let me show a typical cross-section of a window, I don't know if it doesn't

look much like a window, but this is a cross-section of a double pane window.

The original brand name for

this was thermal pane and sometimes that's used as a generic term.

The outside is over here, right.

Then we have a layer of glass.

You could have coatings, number 2 and 3, inside the glass, another plane of glass.

There's a spacer here at number 6, and the whole window structure is sealed and

insulated from the rest of the house.

If I only had one glass pane, there's an R value of insulation.

And this type of symbol or number that shows you

how good of insulation you have various across the world.

So I'm using the US standard, but I'm illustrating a particular point.

R1 is basically a single pane of glass.

Okay, and you might remember or you've experienced if you

touch just a single pane a glass, it's a terrible insulator.

It's cold outside, the inside of the glass is cold.

If it's warm outside, the inside of the glass is warm.

And the sunlight goes right through.

Either heating or if the night, the ambient heat and

infrared radiation goes right out.

So what can you do?

Well clearly, here you could put a second pane of glass.

And if you do that, as you might imagine, you can double the insulation property.

This number represents how good of an insulation barrier it is.

So R = 2 is double pane.

Still though, the windows are the leakiest part of a house.

In their walls, just a simple 3.5 inch batting of

fiberglass insulation might be something of R12 in your roof.

Since heat goes up that's where you really need insulation.

You might have some thicker layers that might be in the 20s or even R30.

The windows are your leaky spot.

So what can you do?

Well modern technology has helped us here, because inside that space at number 6,

you don't have to use just air.

You can use something like argon gas, okay?

Argon-filled windows.

Argon conducts heat much worse,

maybe about two-thirds the value of air conducting heat.

Argon is harmless, vaporless, it's fairly heavy.

It's not that uncommon in the atmosphere, so

it's not that expensive so they can fill argon gas.

Now, if it ever starts leaking, of course, you don't have your argon protection.

And there's other things you can do,

you see on these coatings inside here, number 2 and 3.

You're never going to touch this, so the coating's not going to come off, so

you don't have to worry about that.

You need to make the coating clear, of course.

But if you don't make it clear for infrared light,

in the winter you want the sunlight to come through and

then the coating can prevent the infrared wasp to come out.

They call this low-e glass, low-e emissivity.

There are even more complicated schemes where the layer that coats

the glass can be very, that's electrochromic glass.

It's much more expensive, but

it allows you on a too hot of a day inside to let the heat go through the coating.

And on a very cold day, where you want to capture the heat, you can adjust it,

so the heat and the ambient light cannot come in as much.

If you do these things, you can get to about R = 3.

That's about as good as you can do on glass.

Now clearly, you could add a third pane and a fourth pane and a fifth pane, but

the costs are going up and your visibility through the window starts going down.

It becomes heavier and the like.

So insulated homes has certainly been a plus and when

people recognize that their pocketbook is affected because they have to

pay more to heat their houses, they start saying hey, what are the cheap solutions?

Let's put more insulation in, let's do weather stripping around there and

every time there's a surge in natural gas prices or home heating oil prices,

or the things that people use and

have to pay in the winter, our architecture becomes a little greener.

Building designations are now, for large commercial buildings,

are given designations of bronze, platinum, gold.

Some standards that are set up across the world, these differ.

But people build to those standards and make more energy-efficient buildings.

The very oldest buildings often to get the right temperature you have to have both

a heating system and an air conditioning system on at the same time.

That, of course, is a tremendous waste of energy.

So one of the things that's made things more efficient

is having better building design and more insulation.

That's not the whole story.

There are other things that have become more efficient.

One of them is lighting.

A compact fluorescent bulb uses one-quarter of the energy of

an incandescent bulb, the normal playing white bulb that has the filament

that Edison helped invent and create.

They use only one-quarter of the energy yet they give the same amount of light.

And now we have a new transformation even beyond compact fluorescence to

LED lighting which gives even more light output for

less energy consumption, so that's helpful.

Another has been motors.

In industry, you almost always pay for something going around in a circle.

In the very old days, you'd have electric motors, and

if you needed to run a process slower, you didn't change the speed of the motor,

you use some gearing system, some pulley system that just

basically throttled it down, but that didn't change your energy use.

Variable speed motors were invented and perfected, and

now the motor only uses as much electricity as you need.

So industrial processes like

many of the things that go into factories have become more energy efficient.

We also have done a better job on transportation.

Here's a slide of the miles per gallon,

the average fuel economy in the United States.

This is actually a very clever graph,

because it shows you the average fuel mileage.

And in America, we think about it as miles per gallon, I know in Europe,

they think of it as how many liters are used to go a certain distance,

but generally, in this graph, a higher number is better.

More miles, more distance you can travel per unit of fuel per gallon.

You can see back when the first Arab Oil Embargo hit in the 72 and then in 79.

There was a huge effort to increase the miles per gallon.

And that's because prices had gone dramatically higher and as soon as you hit

the pocketbook people start trying to buy cars that get more fuel efficient.

And when you have to buy cars that get more fuel efficient,

it means car manufacturers make cars that are more fuel efficient.

This is production-weighted adjusted fuel economy

for the cars that are sold in America.

Yes, we use a lot of imported cars, Japan, Korea, other places.

This graph accounts for that.

And it's also interesting, that it shows you this blue band, and

that's 50% of the cars, so most of the cars are right here.

But also shows you the absolute most efficient ones and

the absolute least efficient ones.

The highest percentages and the lowest percentages.

So it gives you the whole spectrum of the miles per gallon of the cars that have

been sold and therefore are now in use in the United States.

Yes, that there are a couple of other upturns.

This is going generally along here and we have a more dramatic upturn here,

once again around 2007, 2008 when gasoline prices sky rocketed.

We were going from $2 or

less per gallon to $4 per gallon seemingly in the space of a year.

That prompted people to once again care about fuel efficiency,

meaning they were trying to buy those types of cars,

meaning the manufacturers make those kinds of cars.

Another aspect came up, which was the first hybrid car,

the first hybrid electric vehicle where you could actually use

a gasoline engine to run an electric motor.

Which gave you just as much power like you use much fuel.

This is automobiles, America loves trucks,

pickup trucks or SUV built on pickup truck frame.

Big vehicles, I love them, too, I have to say.

And so we need a separate graph for

this classification of these quote light duty trucks.

I'm not talking about the giant semi-truck trailers.

And you can see, we have the same trend.

We have the trend here where we're going up

through the 70s when there was one dramatic price increase.

And then, again, another increase here when we have the next

big giant fuel increase to the American consumer.

Trucks have a smaller range, of course,

because their already lower than the low-end of this.

This type of information is very useful but

it doesn't tell you how many trucks we have compared to how many cars we have.

So I've got that graph for you here too.

Back in the 1980s, trucks were maybe one out of five vehicles, okay.

Pickup trucks now are maybe only one out of six, but a whole new class

of vehicles was invented, the sport utility vehicle, the SUV.

And you'll notice there are ones that are built on truck frames.

That's the most common.

And now, that's almost getting up to half of our cars are not plain old automobiles.

And then SUVs are built on the smaller frames, on the car frames.

A third class of vehicles is the minivan and

I have to say because I have a ton of grandchildren.

I still have a minivan, and minivans are useful and great and

you can see over time, the SUV type of vehicle, because it can also

have three rows of seats has been replacing a lot of the minivans.

So lighting, motors, transportation.

But really, the biggest thing that has influenced the increase in efficiency

in the United States has been a shift from

manufacturing, okay?

Heavy industry, making steel, making railroad cars.

Making large items to service.

Making not things, but making services.

Making things like computer programs, the Internet, banking services.

All of these types of things definitely add GDP.

They add value to the economy, they don't require as much energy to use.

This, first one, I showed you the improvements in insulation,

in architecture, lighting, motors, transportation, and

a shift from manufacturing to service has made the US economy more energy efficient.

And has allowed our energy use which is going like this,

like the rest of the world to pretty much go flat.

Even though our productivity, different graph,

different color of productivity has continued to go up.

Eventually the rest of the world will probably follow suit.

Their energies will go up at sometime, efficiency gains and

more global shifts to out of heavy manufacturing or

at least making heavy manufacturing much more efficient will take place as well.

The concept of a negative watt instead of a million watts,

a megawatt, means making something more efficient, so

you don't have to produce that electricity in the first place.

This is what you need to know about the concept of energy efficiency.

[MUSIC]

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