Tuesday, April 05, 2016
3:18 PM
n-p Junction:
http://hyperphysics.phyastr.gsu.edu/hbase/solids/pnjun.html
Energy Sources:
Next class greenhouse effect
April 13th lab A119 sign in to computers for
simulations and database work
Table:
Energy
source
Fusion
Advantages
Lots of energy highest density
No waste greenhouse
gasses or
radioactive
waste
Infinite powerful
source, no
pollution
Disadvantages
Physics
Need high
Torus of magnets to
temperature and contain rotating plasma.
pressure for
nucleii to fuse.
Containing and
using the energy
is problematic.
Solar
Takes up area, Photoelectric effect
and presently
Photovoltaic cells or
costly, not
direct heater(black pipes
accessible during with water + reflector)
Energy=P/A x A x t
the night
Wind power Renewable,
Inconsistent,
Electromagnetic
Prices
induction.
Not space
decreasing
efficient
Energy = 1/2  A v3
Loud, damage to Is the density of the
birds and bats
medium, A is the crosssectional area or the
blades. v is fluid speed.
Biofuels and Carbon neutral, Less efficient,
Exothermic reaction,
waste
grow it and burn more costly,
heats water to steam
it. Biotakes a lot of
and turns turbine for
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Gas
coal
it. Biodegradable,
sustainable,
Easy to
transport, easy
to get,
Cheap, long
burning,
abundant,
geothermal Renewable, no
co2 emission,
upkeep cheap,
fission
High energy
density, low
greenhouse gas
emissions,
mining uranium
is relatively
cheap. Breeder
reactors
produce
plutonium for
bombs?
hydro
batteries
Tidal power
Wave
power
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takes a lot of
and turns turbine for
water and soil, electricity, or run an
clogs engines,
engine.
Low energy
See above
density,
greenhouse
gasses,
hazardous,
needs to be
refined.
Creates
See above
greenhouse
gasses and
particulate
matter, mining
bad for
environment.
Certain locations, Q=mcT
can release
gasses,
Building reactors Uranium 235 decays
is expensive,
when hit by slow neutron
radioactive
into daughter nucleii and
waste,
more neutrons.
meltdowns,
breeder reactors
produce
plutonium for
bombs?
Energy
source
Solar
wind
hydro
Advantages
Disadvantages
Low emissions,
renewable, sun
has lots of
energy
Low emissions,
renewable,
Low efficiency,
not viable in
Raincouver,
Low emissions,
renewable,
reservoir of
water,
Physics
2 types, photovoltaic
cells (photo electric
effect) - black pipes and
mirrors - hot water
Ugly?, not
Electromagnetic
always windy,
induction from spinning
maintenance, kill coil near a magnet.
birds and bats, maxEnergy = 1/2  A v3
noisy
Is the density of the
medium, A is the crosssectional area of the
blades. v is fluid speed.
Loss of habitat, Mgh - induction
ecosystem
See wind for water flow
problems, water
use conflict,
sedimentation,
geothermal Low emissions, Limited locations, Q=mcT could turn a
sustainable,
can be
turbine if hot enough to
expensive,
boil water
limited power.
tidal
Low emissions, Locational
See hydro or turbine
consistent,
limitations, high
upfront cost,
disturbs habitat
Fossil fuels, Cheap, easily Produces
Turbine driven,
Gas, coal found, income, greenhouse
low energy
gasses and
density
particulates
(smog)
especially coal,
fission
fusion
wave
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wave
biomass
Fuel cells
batteries
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