Transcript ENERGY

ENERGY
WHAT IT IS
WHAT IT’S FOR
FORMS OF ENERGY
FIRE
Matter and Energy
Energy is the
abilityto do
work.
Force x Distance = Work
Read an online book about energy.
Kinetic vs. Potential
• Potential energy is
stored energy.
• Kinetic energy
involves motion.
Learn about the different forms
and sources of energy.
FORMS OF ENERGY
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HEAT
LIGHT
MOVEMENT
ELECTRICAL
NUCLEAR
CHEMICAL
FOOD WEB: ENERGY IN
THE ENVIRONMENT
• Chemical energy
changes into
– Heat
– Movement
– sound
Law of conservation of energy
• ENERGY CANNOT BE CREATED OR
DESTROYED
• ENERGY CAN CHANGE FORM
– COAL--HEAT--MOVEMENT-ELECTRICITY--LIGHT
• The sun makes energy from matter
(atom bombs, too) E=mc2
ENERGY IS IMPORTANT!
• ENERGY: THE ABILITY TO DO WORK
– ALL ACTIVITY TAKES ENERGY
– ALL LIFE NEEDS ENERGY
• WHEN ENERGY CHANGES FORM SOME
IS LOST (ENTROPY)--HEAT FROM
YOUR ENGINE
– LIFE USES CONSTANT INPUTS OF
ENERGY FROM THE SUN
SOME ENERGY
CHEMISTRY YOU KNOW
• COMBUSTION: BURNING
– CH4 + O2
HEAT + H2O + CO2
• RESPIRATION: ENERGY FOR CELLS
– C6H12O6 + O2
HEAT + H2O + CO2
• PHOTOSYNTHESIS (STORES ENERGY)
– LIGHT + H2O + CO2
C6H12O6 + O2
Energy needs of life
– Heterotrophs
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consumers
animals
fungi
most bacteria
– Autotrophs
• producers
• plants
• photosynthetic bacteria
(blue-green algae)
Energy cycle
sun
Photosynthesis
CO2
H 2O
glucose
Cellular Respiration
The Great Circle
of Life!
Where’s Mufasa?
ATP
O2
Potential to Kinetic
Potential Energy
(fuel)
Heat Energy
(steam)
Mechanical Energy
(engine parts)
Kinetic Energy
(ship moves)
The Sun is a
Source of Energy
The sun’s energy becomes chemical energy
and is stored in plants as potential energy.
Energy sources
• Sun: energy for almost all life
– Producers: use photosynthesis to store energy from the
sun
– Consumers: eat producers or other consumers
– Plant/herbivore/carnivore/omnivore/decomposer
• Fossil fuels: from fossil plants and animals
– Coal
– Oil (crude oil, petroleum)--diesel, gasoline, kerosene,
butane, propane, motor oil, grease
– Gas--methane, natural gas
• Food
– Carbohydrates (4 kcal/gram)
– Fats (8 kcal/gram)
High cost of energy
• Food production for people uses up
habitat, requires pesticides and
fertilizers
– Pesticides are poisons--biodegradable?
– Fertilizers cause algae in water
– Farms are really bad
• Fossil fuels (carbon based fuels) MADE BY
DEAD CRITTERS.
– Most pollution!
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CO2 and climate change
Acid rain from coal smoke
Mountain top removal and open pit coal mines
Oil spills
Smog
Mercury and lead in exhaust
– Why do we use them?
• Easy to use
• We have lots (coal in US)
• We really really need energy!! WE ARE WILLING TO
HARM OURSELVES AND THE ENVIRONMENT TO
GET IT.
Fossil fuel problems
• Greenhouse gasses: CO2, methane
• Source pollution (coal dust, oil spills)
• Combustion pollution
– CO2
– Mercury
– Sulfur (acid rain)
– Incomplete combustion—city smog
• Waste pollution
– Coal ash—radioactive, toxic
– Smoke—asthma, allergies
• Geopolitical: our enemies have the oil!
ACID RAIN
Other energy: “alternative”
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wind
Nuclear
Tidal
hydro
geothermal
Solar
– Photosynthesis
– Photovoltaics: solar panels (light to volts)
– Passive solar: south facing windows
Passive Solar
Photovoltaics: solar panels
turn light into volts
Wind power classes 3 (300-400 W/m2) to 7 (800-2000 W/m2) are suitable
for wind power development
WIND
GEOTHERMAL
• COMMERCIAL: electrical generation
– DEPENDS ON HEAT SOURCE:
VOLCANO OR GEYSER
– ICELAND AND ITALY USE THIS
• RESIDENTIAL: geothermal heat pump
– EXPENSIVE UP FRONT COST
biofuels
• Bio diesel
• Ethanol: alcohol from fermenting corn
or sugar cane
hydropower
• Need rivers with gradient (slope or
elevation)
• Damn river to store and elevate water
• Water goes through pipe and turns
turbines to make electricity
• Damns silt in, block fish, disrupt nutrient
delivery to land during floods
Nuclear
• Fusion: what the sun does
– Power plants: may be
– No radiation
• Fission: atom bombs and nuclear power
plants.
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Big, expensive
Weapons
Radioactive waste
Accidents: there has not been a new nuclear
power plant built in the US since 3 mile island
accident in 1979!
– No CO2
– US has lots of uranium
-There are 109 power reactors in the United States
-Produce 22% of nation’s electricity
- In France 79% of electricity comes from nuclear reactors
Nuclear Power
-Plant electrical output 1220 MW
-Plant efficiency 34%
Diablo Canyon - California
Nuclear power around the
globe
• 17% of world’s electricity from nuclear power
– U.S. about 20% (2nd largest source)
• 431 nuclear plants in 31 countries
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103 of them in the U.S.
Built none since 1970s (Wisconsin as leader).
U.S. firms have exported nukes.
Push from Bush/Cheney for new nukes.
World Nuclear Reactors
Three mile island in Pennsylvania almost blew up
• Chernobyl
• kaboom
Radiation and Health
• Health effects as a result of radiation exposure:
-increased likelihood of cancer
-birth defects including long limbs, brain
damage, conjoined stillborn twins
-reduced immunity
-genetic damage
High level Nuclear Waste (Dry Cask) Storage
Conceptual
diagram of
the Yucca
Mountain
facility
Proposed nuclear waste repository: Yucca Mountain in Nevada
FOSSIL FUELS CAUSE ALMOST
ALL OUR POLLUTION
PROBLEMS
• ACID RAIN: SULFER FROM COAL
SMOKE MAKES SULFERIC ACID
• CLIMATE CHANGE
• PARTICULATES
• SMOG
• LEAD, MERCURY
Even within the U.S., the highest emitting plants emit SO2,
NOx, and CO2 at rates several times that of the lowest
emitting plants, on a per-btu basis.
Conservation: use less
• Corporate Average Fuel Economy (CAFÉ
standards)
• Drive slower
• Smaller engines
• Compact fluorescents
• Smaller houses
• Walk, bike, etc.
• Cut power to electronics
• ALTERNATIVE ENERGY
– NON FOSSIL
– RENEWABLE
SUMMARY
• Energy is important: DON’T WASTE IT!!
CONSERVATION IS THE EASIEST WAY TO
IMPROVE THE SITUATION
• Fossil fuels: coal, oil, natural gas
– Cheap
– Portable
– Polluting!!!
• Nuclear
• Alternative energy: limited by nature
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Solar (passive and photovoltaic)
Wind
Geothermal
Tidal