Chapter 10 Energy

Big Question

Can We Ensure a Reliable Supply of Energy?

Wind turbines inEastern Washington

Types of Fuels

• Conventional or Alternative

• Conventional - fossil fuels including oil, gas and coal

• Alternative – include wind, solar, water, wood, nuclear, and geothermal.

• Conventional fuels are non-renewable, some alternative fuels are renewable

Petroleum Products: Oil

• Oil is very abundant, but known supplies are dwindling

• The oil resource is the entire amount on Earth (total resource).

• An oil reserve is the portion of the resource that we can extract now at a profit (proven reserve)

When will we reach peakproduction?

• World crude oil production is expected to peak between 2020 and 2050 and cease by 2100

• Estimated total reserve is 3 trillion barrels of oil

• Two other sources of oil are oil shale and tar sands.

Petroleum Products: Natural Gas

• The worldwide known recoverable natural gas will last approximately 70 years at the present rate of use

• However it has only recently been widely exploited, and more reserves are expected to be discovered

Coal

Centralia, WA coal-fired powerplant produces about 10% ofWashington State's energy

How Coal is Made

• Formed as dead vegetation was buried in sediments

• Then crushed, heated and transformed over millions of years into carbon rich sedimentary rocks

• Other chemical elements and soil particles mixed with the dead plants and form impurities

The Environmental EffectsAssociated with Coal

• Coal may be extracted from underground mines or from strip mining such as at Black Mesa

• Strip mining involves digging the coal out from the surface.

• Produces soil erosion, increased flooding risk and acid runoff

Environmental Effects Associated with Petroleum Products

• Air pollution from combustion

• Leaks and spills during storage, transportation and refining

• In 1989 the supertanker Exxon Valdez ran aground in Prince William Sound Alaska, and spilt 250,000 barrels (11 million gallons)

Alternatives Energy Sources: Solar

• Solar energy is renewable and therefore sustainable.

• Solar energy is stored in wind, water, tides, ocean currents, and organic matter (biomass)

Passive solar energy

Historically, houses were designed and oriented to collect and use sunlight for heating

• Solar collectors store the sun’s energy to provide space heating and hot water

Active solar Energy

• Photovoltaics (PVCs) convert sunlight directly into electricity

• Thin layers of semiconductors produce an electric current when sunlight falls on them

• Energy conversion efficiency has increased from 1–2% up to 18%

Wind Power

Water Power

Grand Coulee Dam in Washington State. Note the outlet in the right hand corner for irrigation water. The dam serves to generate electricity (87% of Washington's) and provide irrigation

water. Wikipedia photo.

Tidal Power

The primary areas with potential for

tieal power are highlighted in yellow.

Most studies show Admiralty Inlet as the highest potential for

tidal power due to the strong currents there.

Biomass Energy

Biomass energy is a "closed" cycle, except for the use of any fossil fuel to utilize it.

Fiat flex car. Note sugarcane in background,

the primary source of fueld for cars in Brazil

Pellet stove heating home. Pellet fuel is wood-based, so

it is renewable "recent" carbon and doesn't

contribute to global CO2 except for the electricity

used to produce and run the stove and transport the fuel

Geothermal Energy

Nuclear Energy

Nonbreeder Reactors: Fission Reactors• 1 kilogram (2.2 pounds) of uranium oxide produces

as much heat as about 16 metric tons of coal.

• The heat from nuclear fission makes steam to run turbines that generate electricity.

Environmental Problems ofNuclear Power: Three Mile Island

• A cooling failure led to a meltdown on March 28, 1979

• A main water pump failed, increasing pressure• A pressure release valve reduced pressure, but

then failed to close, and cooling water poured out

• Reactor core overheated, leading to a partial core meltdown

• Intense radiation was released inside the plant, and some escaped into the atmosphere

Chernobyl

• Cooling system failed, causing the temperature of the reactor core to rise to over 3000°C (5400°F), melting the uranium fuel.

• Explosions removed the top of the reactor building

• Graphite surrounding the fuel rods caught fire.

Radioactivity

Energy: Storing it

The Grand Coulee Dam is the world's 5th largest, and includes a pump-

storage facility, including the ability to flood Grand Coulee. Note the canal in the upper right hand corner. Water is pumped up into the canal, and can

also be pumped back into the reservoir when there is excess electricity.

Energy: Transporting it

Conserving Energy

The UW's Center for Urban Horticulture, replaced after being burned by ecoterrorists, was the UW's first certified "green"

building on campus.

• Design residential and office buildings to use sun and wind

Steps to Energy Conservation

UW students conserving energy by walking and riding bikesSource UW homepage, Traillink.com