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APES Chapter 17
Terms in this set (41)
What is energy?
Energy is the ability to do work or make something move.
What are the various forms of energy
Potential energy- stored energy, usually high quality.
chemical- coal, oil, natural gas, food
nuclear- stored in atomic bonds
gravitational- water behind a dam, object at top of hill
Solar energy- light from the sun (EMR), energy source for Earth's biota.
Kinetic energy- due to object's motion.
Heat energy- the random motion of molecules. (heat ≠ temperature)
1st Law of Thermodynamics
Energy cannot be created or destroyed (it can be converted from one form to another) ** conservation of energy
2nd Law of Thermodynamics
When energy is changed from one form to another, some energy is converted to heat. entropy increases, quality decreases, energy cannot be recycled or go from low to high quality
What is entropy
disorder, randomness, ≠ energy
What is meant by energy quality
Energy quality- availability of energy to do work
high quality- organized, easy to convert to work
low quality- disorganized
What is work
Work- exerting a force over a distance (Work= force x distance)
What happens to energy quality and entropy when work is done?
Energy quality decreases and entropy increases when work is done.
What is energy efficiency?
Energy efficiency- the ratio of output obtained from given input, expressed as %
1st law efficiency
work done/energy used
common 1st law efficiencies
total US energy use, an average coal fired power plant, incandescent light bulb, fluorescent light bulb
total US energy use- 50%
an average coal fired power plant- 30-40%
incandescent light bulb- 5%
fluorescent light bulb- 20%
What is 2nd law efficiency
minimum energy needed/actual energy used
usually high quality energy is being used to do tasks low quality tasks.
this is an area of potential energy savings.
What does it mean if the 2nd law efficiency is low
if the 2nd law efficiency is low, the method of producing the specific type of energy, is not fit for producing the energy.
Describe the relationship between standard of living and energy consumption
Energy consumption is directly proportional to level of affluence
The US has 5% of the world's population and accounts for what % of world energy consumption?
25% of world's energy consumption by 5% of population
91% of US'S energy from non-renewable sources (Oil, Natural gas, Coal, Uranium, Propane)
9% of US's energy from renewable resources (Biomass, Hydropower, Wind, Geothermal, Solar)
Over all US efficiency is approximately 50%
What % of US energy comes from fossil fuels
90% of our energy needs come from fossil fuels
What are fossil fuels
Fossil fuels are forms of stored solar energy.
What are the 3 main fossil fuels
3 main fossil fuels are coal, oil, and natural gas.
What are alternative energy sources?
Biomass Energy, Wind Energy, Solar Energy, Geothermal Energy, Hydroelectric Energy
What are renewable energy sources?
energy that comes from resources which are naturally replenished on a human timescale such as sunlight, wind, rain, tides, waves and geothermal heat.
(energy) metric unit, defined by amount of work it can perform
1 Joule= 1 N•m (the force of 1 Newton applied over 1 meter)
(energy) amount of energy needed to raise 1g (ml) of H2O 1ºC
1 calorie= 4.28 joules; 1 joule= 0.239 calories
BTU- British Thermal Unit
(energy) 252 calories= 1055 joules
(energy) 1 quadrillion (1015) BTU's= approximately 1 exajoule
(energy) 1018 joules or a billion gigajoules = approx 1 quad
(energy) 3,600,000 joules
What is power?
Power is the rate of doing work or using energy (must be per unit time)
(power) 1 joule/second= 1 N•m/sec= 1 watt
(power) 747 watts
getting by with less demand for energy
the ratio of output obtained from given input, expressed as %. Involves designing equipment to yield more energy output from a given amount of input energy (1st law of efficiency) or better matches between energy source and end use (2nd law efficiency)
using waste heat to do work. Number of processes designed to capture and use waste heat rather than simple to release it into the atmosphere, water, or other parts of the environment as a thermal pollutant
Negawatt power is a theoretical unit of power representing an amount of energy (measured in watts) saved. The energy saved is a direct result of energy conservation or increased energy efficiency
building design more efficient
solar energy, insulation
industry energy use more efficient
Cogeneration- using waste heat to do work
cars more efficient
better fuel efficiency, hybrids, fuel cells
emphasizes quantity over quality (hard= hardware)
more power plants built to satisfy peak demand, find more oil
changing behavior, increase conservation and efficiency
conservation- use less. what do you really need?
efficiency- getting more from energy you do use (improve technology, fuel efficiency)
integrated energy management- use a diversity of fuels, renewable fuels
What is integrated energy management?
recognizes that no single energy source can provide all the energy required by the various countries of the world
What is sustainable energy development?
-provide reliable sources of energy
-it would not cause destruction or serious harm to our global, regional, or local environments
-it would help ensure that future generations inherit a quality environment with a fair share of the Earth's resources
What is micropower?
Smaller, distributed systems for production for electricity.
THIS SET IS OFTEN IN FOLDERS WITH...
APES Chapter 18
APES Ch. 20 Nuclear Energy
APES Ch. 19 Alternative Energy
APES AP Exam Review Cases/Laws
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