EnergyNon-renewable and Renewable Resources

The Earth’s Interior• Composed of 4 layers

• Crust• Mantle• Outer Core• Inner Core

Crust• Temperature: Over 175 degrees Celsius• Topmost layer of the Earth• Relatively cool• Made of rock• 2 types of crust

• Oceanic (4-7 km thick)• Continental (20-40 km thick)

Mantle• Temperature: Over 1250 degrees Celsius• Makes up about 80% of the Earth’s volume• ~ 2900 km thick• Outer mantle – rocks• Inner mantle – “plastic”

Core• Temperature: Over 6000 degrees Celsius• Outer core – liquid

• Pressure from the mantle & crust do not allow the metals in the outer core to become gasses

• Inner core – solid• Pressure from the mantle and crust do not allow the metals to

become liquid

Plate Tectonics• The Earth’s lithosphere is made up of 7 tectonic plates• Plate tectonics – the movement of these lithospheric plates

Why do the plates move?

• One theory suggests that plates move due to the convection currents in the asthenosphere (“plastic” inner portion of the mantle)

Divergent Plate Boundaries• 2 plates move apart• Magma fills the gap created from this movement• Magma cools as it reaches the Earth’s surface creating rift

valleys

Convergent Plate Boundaries• Oceanic plates dive beneath continental or oceanic plates

(called subduction)• Creates deep ocean trenches

Wall diving- coral reefs form over time on the “walls” of deep sea trenches. Many are thousands of feet deep.

Convergent Plate Boundaries• Mountains form at the convergent plate boundaries as magma

from the mantle rises, pushing continental crust upward

Convergent Plate Boundaries• Volcanoes form at the convergent plate boundaries as magma

rises to the surface and cools

Transform Fault Boundaries• Plates move past each other at cracks in the lithosphere

(called faults)• Transform fault boundary – horizontal movement between

two plates

Earthquakes

• Occur at plate boundaries• Plates slide past each other creating pressure• Rocks break along the fault line• Energy is released, called seismic waves

San Andreas Fault

Focus = point of earthquake origination

Epicenter = point on the Earth’s surface directly above the focus

Energy from an earthquake

• Energy is released in the forms of waves• P wave: Primary or longitudinal waves

originate from the focus & move quickly through rock. These are the first waves to be recorded

• S wave: Secondary or transverse waves originate from the focus & moves more slowly through rock.

• Surface waves: move across the earth’s surface, causes building to collapse

Earthquake Measurement

• Seismograph• Records data about P, S and surface waves• Used to locate the epicenter of an earthquake

• Richter scale• Measures energy released at the epicenter of

an earthquake (in magnitude)• Each step up in magnitude represents a 30-fold

increase in energy released!

Volcanoes

• Volcanoes result from openings or vents in the Earth’s surface

• Magma reaches the surface through these vents• When magma reaches the surface it changes

physically and is called lava

Shield Volcano

• Formed from fluid lava, rich in iron• Shield volcanoes are large

Mauna Loa in Hawaii

Composite Volcano

• Made of alternating layers of lava, ash and cinders.

• Magma is rich in silica and thick• Large with steep slopes

Cinder Cone

• Large amounts of gas are trapped in the magma causing violent eruptions

• Active for short periods of time

Minerals & Rocks

• Minerals: • naturally occurring, inorganic substances

• (inorganic = does not contain Carbon)• can be expressed by a chemical formula• Quartz SiO2 (silicon dioxide)

• Rocks:• Composed of minerals

Types of Rock

• Igneous• Formed when magma or lava cools and hardens

• Magma forms intrusive igneous rock• Lava forms extrusive igneous rock

• Sedimentary• Formed when rock particles, plant and animal

debris are carried away by water, redeposited, then fused together

• Metamorphic• Rock particles are fused together by pressure beneath

the Earth’s surface

Determining the age of rocks

Two ways to “determine” the age of a rock:

1. Superposition – determine the age based on layers, older rocks are on the bottom, newer ones on top

2. Radioactive dating

The Rock Cycle

Weathering and Erosion

• Two types of weathering• Physical

• Breaks rocks into smaller pieces, chemical composition does not change

• May be caused by ice or plants• Chemical

• Changes the chemical composition of rocks• May be caused by oxidation or acid rain

Erosion

• Erosion: the process of loosening and removing sediment• Caused by water, glaciers, wind

Deposition

• Occurs when loose sediment is laid down• Causes river beds to widen and deltas to form.

Important Elements

• Oxygen – most abundant element in the Earth’s crust

• Nitrogen – most abundant element in the atmosphere

• Iron – most abundant element in the core

Non-renewable Resources

• Defined:• An energy source that cannot be renewed in our

lifetime

• Examples:• Oil• Natural Gas• Coal• Aluminum• Gold• Uranium

Non-renewable resources – Environmental Impacts• Mining

• IMPACTS:• Disrupts land• Disrupts ecosystems• Causes acid rain

Surface Mining• Description – if resource is <200 ft. from the

surface, the topsoil is removed (and saved), explosives are used to break up the rocks and to remove the resource, reclamation follows

• Benefits – cheap, easy, efficient• Costs – tears up the land (temporarily),

byproducts produce an acid that can accumulate in rivers and lakes

Underground Mining• Underground Mining

• Description – digging a shaft down to the resource, using machinery (and people) to tear off and remove the resource

• Benefits – can get to resources far underground• Costs – more expensive, more time-consuming,

more dangerous – mining accident in Chile

Coal• formed from ancient peat bogs (swamps) that

were under pressure as they were covered.• Used for electricity, heat, steel, exports, and

industry, may contribute to the “Greenhouse Effect”

• Four types of coal exist: lignite (soft, used for electricity), bituminous and subbituminous (harder, also used for electricity) and anthracite (hardest, used for heating)

• 50% of all the coal is in the United States, the former Soviet Union and China

Fig. 16-12, p. 368

Increasing heat and carbon content

Increasing moisture content

Peat (not a coal)

Lignite (brown coal)

Bituminous

(soft coal)

Anthracite

(hard coal)Heat Heat Heat

Pressure Pressure Pressure

Partially decayed plant matter in swamps and bogs; low heat content

Low heat content; low sulfur content; limited supplies in most areas

Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content

Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas

Fig. 16-13, p. 369

Waste heat

Coal bunker TurbineCooling tower

transfers waste heat to

atmosphere

Generator

Cooling loop

Stack

Pulverizing mill

Condenser Filter

Boiler

Toxic ash disposal

COAL• Coal reserves in the United States, Russia, and China could last

hundreds to over a thousand years.• The U.S. has 27% of the world’s proven coal reserves, followed

by Russia (17%), and China (13%).• In 2005, China and the U.S. accounted for 53% of the global coal

consumption.

Reclamation

• returning the rock layer and the topsoil to a surface mine, fertilizing and planting it• Benefits – restores land to good condition• Costs – expensive, time-consuming

• In the United States, mining companies are required to do this!

Open-pit Mining• Machines dig holes and

remove ores, sand, gravel, and stone.

• Toxic groundwater can accumulate at the bottom.

Figure 15-11

Area Strip Mining• Earth movers strips away

overburden, and giant shovels removes mineral deposit.

• Often leaves highly erodible hills of rubble called spoil banks.

Figure 15-12

Contour Strip Mining• Used on hilly or

mountainous terrain.• Unless the land is

restored, a wall of dirt is left in front of a highly erodible bank called a highwall.

Figure 15-13

Mountaintop Removal• Machinery removes the

tops of mountains to expose coal.

• The resulting waste rock and dirt are dumped into the streams and valleys below.

Figure 15-14

United States mining

• Central – diamonds (Arkansas), bituminous coal• West – bituminous and subbituminous coal, gold,

silver, copper• East – anthracite coal, bituminous coal• South – some gold (SC), bituminous coal• North – bituminous coal, some gold (SD, WI)

Energy from non-renewable resources• Cogeneration• Primary• Secondary

Fossil Fuels• Only about 30% efficient • Benefits –

• easy to use, currently abundant• Costs –

• a nonrenewable resource, produces pollutants that contribute to acid rain and the greenhouse effect

• Oil- Supplies the most commercial energy in the world today. People in the U.S. use 23 barrels of petroleum per person or 6 billion barrels total each year!!!

Fig. 16-5, p. 359

Gases

Gasoline

Aviation fuel

Heating oil

Diesel oil

Naptha

Grease and wax

Asphalt

Heated crude oil

Furnace

OIL

• Eleven OPEC (Organization of Petroleum Exporting Countries) have 78% of the world’s proven oil reserves and most of the world’s unproven reserves.

• After global production peaks and begins a slow decline, oil prices will rise and could threaten the economies of countries that have not shifted to new energy alternatives.

Case Study: U.S. Oil Supplies

• The U.S. – the world’s largest oil user – has only 2.9% of the world’s proven oil reserves.

• U.S oil production peaked in 1974 (halfway production point).

• About 60% of U.S oil imports goes through refineries in hurricane-prone regions of the Gulf Coast.

Heavy Oils from Oil Sand and Oil Shale: Will Sticky Black Gold Save Us?

• Heavy and tarlike oils from oil sand and oil shale could supplement conventional oil, but there are environmental problems.• High sulfur content.• Extracting and processing produces:

• Toxic sludge• Uses and contaminates larges volumes of

water• Requires large inputs of natural gas which

reduces net energy yield.

Oil Shales

• Oil shales contain a solid combustible mixture of hydrocarbons called kerogen.

Figure 16-9

Core Case Study: How Long Will the Oil Party Last?

• We have three options:• Look for more oil.• Use or waste less oil.• Use something else.

Figure 16-1

NATURAL GAS

• Natural gas, consisting mostly of methane, is often found above reservoirs of crude oil.• When a natural gas-field is tapped, gasses are

liquefied and removed as liquefied petroleum gas (LPG).

• Coal beds and bubbles of methane trapped in ice crystals deep under the arctic permafrost and beneath deep-ocean sediments are unconventional sources of natural gas.

NATURAL GAS

• Russia and Iran have almost half of the world’s reserves of conventional gas, and global reserves should last 62-125 years.

• Natural gas is versatile and clean-burning fuel, but it releases the greenhouse gases carbon dioxide (when burned) and methane (from leaks) into the troposphere.

Nuclear

Economics

Energy Efficiency – Non-renewable energy sources• Coal, Natural Gas, Oil: about 30% efficient• Nuclear:

Laws of Thermodynamics• 1st law: Conservation of Energy

• Energy cannot be created nor destroyed• Energy can be transferred from one system to another

• 2nd law: • Energy transfer must only have one direction• Entropy (disorder) increases over time

• 3rd law:• Absolute zero is achieved when all kinetic energy stops

SO…..• 1st law of Thermodynamics

• Explains how we can convert energy from chemical or mechanical energy to usable electric energy

• windmill animation

• 2nd law of Thermodynamics explains WHY energy efficiency can be so low

Renewable Energy

Solar

• Solar energy is harnessing energy from the sun’s rays• Passive Solar – Placing buildings strategically to

take advantage of the sun’s heat• Example: Log Homes

• Active Solar – uses solar panels to convert energy into a usable form such as electricity

Fig. 17-17, p. 398

Single solar cellSolar-cell roof

–

Boron enriched silicon

+

Junction

Phosphorus enriched silicon

Roof options

Panels of solar cells

Solar shingles

• Benefits of Solar:• Readily available• Renewable• Fairly simple system• Pollution free energy source• Can sell back extra energy to the power company

• Drawbacks of Solar:• High start up cost for active solar energy system• Location dependent (Seattle would not be a good

city for solar energy)

Core Case Study: The Coming Energy-Efficiency and Renewable-Energy Revolution

• It is possible to get electricity from solar cells that convert sunlight into electricity.• Can be attached like shingles on a roof.• Can be applied to window glass as a

coating.• Can be mounted on racks almost

anywhere.

Core Case Study: The Coming Energy-Efficiency and Renewable-Energy Revolution

• The heating bill for this energy-efficient passive solar radiation office in Colorado is $50 a year.

Figure 17-1

Passive Solar Heating

• Passive solar heating system absorbs and stores heat from the sun directly within a structure without the need for pumps to distribute the heat.

Figure 17-13

Fig. 17-13, p. 396

Direct Gain

Summer sunHot air

Warm air

Super-insulated windows

Winter sun

Cool air

Earth tubes

Ceiling and north wall heavily insulated

Fig. 17-13, p. 396

Greenhouse, Sunspace, or Attached Solarium

Summer cooling vent

Warm air

Insulated windows

Cool air

Fig. 17-13, p. 396

Earth Sheltered

Reinforced concrete, carefully waterproofed walls and roof

Triple-paned or superwindowsEarth

Flagstone floor for heat storage

Fig. 17-14, p. 396

Trade-Offs

Passive or Active Solar Heating

Advantages Disadvantages

Energy is free Need access to sun 60% of time

Net energy is moderate (active) to high (passive)

Sun blocked by other structures

Need heat storage system

Quick installation

No CO2 emissions

Very low air and water pollution

High cost (active)

Very low land disturbance (built into roof or window)

Active system needs maintenance and repair

Moderate cost (passive)

Active collectors unattractive

Cooling Houses Naturally

• We can cool houses by:• Superinsulating them.• Taking advantages of breezes. • Shading them.• Having light colored or green roofs.• Using geothermal cooling.

Wind• Wind energy is converted into a usable energy form by using

wind turbines

www.lacoastpost.com www.windenergyplanning.com

Wind Power

• Benefits of Wind Power:• Readily available• Can sell back extra power• Pollution free energy source

• Drawbacks of Wind Power:• Disrupts migration patterns• Turbine farms are not aesthetically pleasing• Turbines are expensive• Good for specific locations only

Hydro

• Hydro power is mechanical energy derived from water

• Most hydropower is generated by damming rivers

• Using waves or ocean currents is being researched as a source of hydropower

www.southeastasia.biz

Three Gorges Dam in China

www.livescience.com

Three Gorges Dam

• 1.5 miles long • 574 feet deep • $23 billion• 13 cities and 1,300 villages were flooded

www.howstuffworks.com

• Benefits of Hydropower• Readily available• No pollution produced• Constant source of power

• Drawbacks of Hydropower• Damming rivers disrupts ecosystems, causes

sediment to build up and disrupts the natural flow of a river

Geothermal

• Geothermal energy uses natural underground heat sources

• When heat escapes the earth in the form of steam, the steam is used to turn a steam turbine which converts the heat energy into electrical energy

• Benefits of Geothermal:• When drilled correctly, little pollution is

produced• Takes up a relatively small area, does not

disrupt the landscape• Drawbacks of Geothermal:

• Can only be used in a limited capacity• Very location specific• May run out of steam• May release hazardous gasses or minerals if

drilled improperly

Biomass

• Biomass is burning biomass fuel in a specialized burner. Steam generated turns a steam turbine which turns mechanical energy into electrical energy

Biomass at the Denver Zoo!• Trash and animal waste

is converted into pellets• The pellets are put into

a gassifier and heated to 400 degrees!

• When hot enough, a gas is emitted that is converted by micro gas turbines into electrical energy

• Denver Zoo

• Benefits of Biomass• Less waste in landfillsReadily available

• Drawbacks of Geothermal• Not currently available on a large scale basis

USING RENEWABLE SOLAR ENERGY TO PROVIDE HEAT AND ELECTRICITY

• The European Union aims to get 22% of its electricity from renewable energy by 2010.

• Costa Rica gets 92% of its energy from renewable resources.• China aims to get 10% of its total energy from renewable

resources by 2020.• In 2004, California got about 12% of its electricity from wind

and plans to increase this to 50% by 2030.

Energy Efficiency – renewable energy sources• Solar• Wind• Hydro• Biomass• Geothermal

USING RENEWABLE SOLAR ENERGY TO PROVIDE HEAT AND ELECTRICITY

• Denmark now gets 20% of its electricity from wind and plans to increase this to 50% by 2030.

• Brazil gets 20% of its gasoline from sugarcane residue.

• In 2004, the world’s renewable-energy industries provided 1.7 million jobs.