Energy Concepts Flashcards
Energy units
joule, calorie, british thermal unit, kilowatt hour
Power units
Watt, horsepower
Laws of Thermodynamics
- Energy can not be created or destroyed, only transformed
2. Entropy (chaos) increases because energy lost as heat or other forms in transformations
Energy
capacity to do work
Potential energy
energy at rest
Kinetic energy
energy in motion
Radiant energy
sunlight
Convection
transfer of heat by movement of heated matter
Conduction
transfer of energy through matter
Fossil fuels provide ___ of the world’s electricity.
64%
____ energy provides 17% of the world’s electricity.
Nuclear
Renewable energy sources provide ___.
19% of the world’s electricity.
Coal
purest- anthracite, then bituminous, then sub-bituminous, worst is lignite
scrubbers remove sulfur dioxide
fly ash and boiler residue are waste products
(found on land)
Oil
crude oil is what is pumped out
most environmental damage is from transporting thousands of miles
(found in water)
Natural Gas
mostly methane, but also pentane, butane, etc
comes from wetlands and livestock
transported in gas tanks as liquefied natural gas, compressed
Nuclear Energy
nonrenewable, non-fossil fuel
use uranium-238 with a 3% uranium-235
isotopes are split with fission
two types of reactors- boiling water and pressurized water
Hydroelectric Power (dams)
moving water turns a turbine which generates electricity
production releases no pollutants
does produce thermal pollution and dams rivers, which destroys habitats
Bad: huge buildup of sediment behind dam
Fish can’t spawn unless they have fish ladders to go upriver
Energy Conservation
biofuel- fuel made of something other than fossil fuels, such as cooking oil
important to find alternative fuel sources
CAFE, Corporate Average Fuel Economy, set standards for mile per gallon for cars
hybrid vehicles run on electricity and gasoline only for starting and stopping car
Renewable Energy
Hydroelectric, solar, wind, geothermal, ocean tides, hydrogen cells
Solar
passive solar energy collection- collect sunlight with windows and building placement
active collection- solar panels
photovoltaic cells- collects solar energy, produce electricity to store in batteries
Wind
turbine- wind turns blades, main part of wind turbine
nacelle- gearbox and generator to control turbine
wind farms- wind turbines put in groups
Geothermal
energy from within earth, takes earth’s internal heat from heated water and steam
