Part 1: energy overview

Earth at night

Earth lights

Population and per capita consumptionare the driving forces behind energy use

and climate change

Energy use per capita

Haves and have-nots

US energy use

US: 1949-2007

Last time wehad “Energyindependence”

USenergy

production

US energy consumption

World consumption

US energy projections

Basic termsrenewable energy sources: energy sources for which thedemand rate (or use rate) is less than or equal to theproduction rate.

example... if trees are cut down faster for firewoodthan they can grow back, trees are non-renewable energysources. If they grow back faster than they are cut down ( or ifthe cutting rate is equal to the growing rate) then trees arerenewable energy sources.

This, of course, does not take into account other uses oftrees... how will other uses affect whether trees are renewableenergy sources or not?

Energysources

Non renewable energy sources

1. oil2. natural gas3. coal4. nuclear5. fuelwood

Renewable energy sources

1. hydropower (water)2. windpower3. solar power4. geothermal

Notesa. hydropower and wind power are really manifestations of solar power...they are separated here only for historical reasons.

b. fuelwood can be either renewable or non renewable

c. nuclear power is technically non renewable.. but potentially it will lasta long time...

d. hydropower includes tidal power

e. these are primary sources of energy. Many other forms can be derivedfrom these, such as electricity, hydrogen, etc.

World energy use as a function oftime

Consumptionby region

AChanging

World

Energy use: the fossil fuel issue

Fossil fuels and CO2

Fossil fuels and CO2: The future

Energy use and OPEC

Energy use and wealth

Relationship isnot perfect, butit is significant

Public awareness?

Time/ABC/Stanford poll:• About 85% of Americans say global

warming is happening…right• But 65% think scientists disagree

about global warming…wrong• And 81% oppose higher taxes on electricity,

68% oppose higher gasoline taxes• Perception and reality… the first step is

admitting you have a problem… living on afault line…

Publicawareness… or lackof it… polltaken inDenverafter a

month ofsnow and

coldweather

Forms of energy

1. chemical: energy stored in materials that can be released bychemical reactions (such as combustion); examples includefood, oil, batteries

2. heat: energy in moving molecules that we perceive astemperature (warmer = more motion)

3. mass: energy and mass can be interchanged… nuclearreactions

More forms of energy4. kinetic: energy of motion, a form of mechanical energy; amountdepends on mass and speed of moving object (an SUV has more thana Honda Civic)

5. potential: energy associated with position in a force field; obviousexample is object in gravitational field.

6, electrical: charged particles have potential energy, depends onvoltage and charge

7. electromagnetic: energy radiated by all bodies (sun is a goodexample)

Key energy pointsKey points to keep in mind:

Energy cannot be created or destroyed, it can only beconverted from one form to another

Whenever you convert energy from one form to another,you do so at less than 100% efficiency… generally atmuch less than 100% efficiency…

Energy tends to go from useful forms (heat) to less usefulforms (entropy)

Energy Reserves and the R/P Problem

R/P = reserves/production rate

units are:Time = amount/(amount/time)

R/P spinningR/P is a dynamic concept... and thus one subject to abuseand misunderstanding.

reserves are constantly changing...

production rates are constantly changing...

reserves and production rates are notindependent...

production rate can be confused with consumption rate...They can be different

R/P spinningAs long as use increases with populationand use per capita increases, unlessreserves increase exponentially, R/P willalways be inflated

R/P concepts

1. History of R/P

2. What stabilizes R/P?

3. What is the future of R/P?

The R/P worksheet

Fossil fuels are not just fuels

Background thoughts:what are the characteristics of an ideal energy source?

•low pollution (are there any non-polluting sources?)•abundant (cost)•dependable (solar in the winter in Norway?)•well distributed (Gulf War)•useful in many applications (nuclear in a car?)

what are the merits of multiple versus single energy sources?

•is there a single, ideal energy source?•how is energy used in industry, transportation andresidences and businesses?

Wheredoes ourenergycomefrom?

Less than 1Less than 1GeothermalLess than 1*Less than 1*SolarLess than 1Less than 1Windpower

76Hydropower15Fuelwood

43Nuclear3026Coal2017Natural gas3833Oil

Percent usewithoutwood

Percent useEnergy type

Take home points• Fossil fuel use is 76%, or 88% not including fuel wood• Wind, solar, and geothermal total about 1%.• Roughly half of the world’s peoples still rely on wood as

the primary energy source• Solar use is intrinsically underestimated as we don't know

how much passive solar energy is used in heating, forexample.

Some basics• The Earth’s resources are finite• Some can be re-used (iron, aluminum,

etc) with a cost (energy)• Others cannot be re-used, they are

converted to other forms (oil to CO2 andwater)

• Humans are very impressive… we usefossil energy far faster than the Earthproduces it (about 50,000 times faster)