AP Environmental Science
To help you plan, here is an outline of our next few weeks:
Week one: Energy overview:
terms, sources, sinks, forms
CC15 ch. 12
PQ 1-16 p. 306
online: http://highered.mcgraw-hill.com/sites/0073383244/student_view0/chapter12/practice_quiz.html
Sem exam corrections due
Week two: non-renewable energy/fossil fuels
Withgott 4e ch 19
testing your comp. (TYC) p. 559, 1-10
iBook: ch. 17, inline questions
Withgott 4e ch. 20
TYC p. 587, 1-10
Week three: renewable energy
Withgott 4e ch. 21
TYC p. 614 1-10
iBook ch. 18 inline questions
(week four: sustainability)
(Withgott 4e ch. 24
TYC p. 688 1-10
I'd like to propose giving you the option of dropping one score from your homework each quarter, with the expectation that there will be no credit for late work.
I'll also make sure that our Sunday week questions will be assigned no later than 3PM on the Thursday or Friday of the week they are due, depending on when our last class of the week meets.
Let's discuss tomorrow, this should give you a good sense of what's ahead to plan with.
You should see the first few assignments already on the Haiku calendar.
Energy notes:
Terms:
Energy = the ability to do work (see in physics, the term is "erg", like "exert")
Energy Units: joules (usually used to define work, often in physics)
Since a joule/sec = 1 Watt, notice that Watt is the RATE we do work. We call this POWER.
Think: climbing stairs-you and someone else, same mass, same height, one takes minutes, one takes hours.
Power is the rate we do work, like jumpers need power.
Back to Watts: 1 Watt = joule/sec so... Watt x time = energy
Electrical work is called Wh or Watt hours (Watt x hours) or more commonly kWh (kiloWatt hours).
Let's make this easier: 1000 Watts on for one hour = 1 kWh
This would cost you $0.45 from our local utility
Electrical units:
Watt = power
Joule = energy
Volt = electrical potential ("pressure")
Ampere = current (flow or flux)
Ohm = resistance
Let's try a sample calculation:
A coffee maker uses 1200 Watts for 15 minutes to heat water (coffee, yum!)
Do the power part first, it's easiest: 1200 W = 1.2 kW, 30 minutes = 1/2 hour, so 1.2 x 1/2 = 0.6 kWh
This would cost us 0.6 x $0.45 or about 27 cents.
Next: some formulas
Power = Volts x Amps (P=Vi)
1200 Watts = 120 volts x 10 Amps
Power = Amps x Amps x Ohms (P = I2R)
Also
Volts = Amps x Ohms (V=iR)
Kill-a-Watt meters
Start with a hot water heater.
Measure the following with the meter:
Volts, Amperes, Watts
Measure the resistance of the heater with one of the yellow meters
Test the formulas above. If they all work, then the power factor (PF) = 1.00.
This is a measure of the electrical efficiency of the device. If the PF were 1.00, you could spend one dollar and only get 50 cents worth of work from the device. Pump motors, power supplies and air conditioners often have PF less than 1.00. All heaters have PF = 1.00
CC15 notes:
Fossil fuels (petroleum, natural gas, coal)
Renewable sources: solar, wind, geothermal, hydroelectric, tidal
Biomass: Wood, ethanol, biodiesel
Nuclear: fission, fusion
Update: IGCC "clean coal" has not been successful, Nat gas is much cheaper due to domestic Fracking (hydraulic fracturing)
Fracking: solvent, high pressure injection, fractures underground structures, releasing methane, butane, propane and others
----end of Tuesday class notes-----
(CH4 is methane, all others just add another C and H is 2n+2)
Peak oil-Hubbert Peak (compare with Intel's Moore's law)
ANWAR-Alaska National Wildlife Refuge
Tar Sands-Wyoming, Alberta (heated to release petroleum) See also the Excel Pipeline from Canada to Houston, where the refineries are
"light sweet crude" What the heck?
Natural Gas can be transported in 2 forms: CNG (compressed natural gas) and LNG (liquified natural gas) often transported via ship
Nuclear power-fission (split) and fusion (join)
Fission fast is an atomic bomb, slower releases thermal neutrons, which can hit a moderator to create heat, then steam.
Steam is the mediator for most large scale energy: oil burns to create steam, coal same thing, nuclear fission same thing
Exception: natural gas turbines are direct to the generator, are much faster and more efficient (no minimum idle)
Nuclear Fission: chain reaction: one neutron hits one Uranium atom, releases 3 neutrons, which hit 3 other Uranium atoms, then 9...
Clue: Fission is always heavy atoms like Uranium and Plutonium, Fusion is always lighter atoms like Hydrogen and Helium (like stars)
Make sure you can draw a nuclear power plant for the AP exam...
There are several types: BWR (boiling water reactor), PWR (pressurized water reactor) and TBR (thermal breeder reactor) more on these later.
Lots to consider about nuclear waste, and controlling these reactors. Submarine reactors are just scaled up for most reactors, note the difference, and the similarity: both need lots of water for cooling. See also Chernobyl, Fukushima and Three mile island (in decreasing order of radiation release). Also, make sure you understand the "China Syndrome".
Conservation: lighting, heating, transportation
Biofuels: wood (gen 1), ethanol (gen 2) cellulosic ethanol (gen 3), see also biodiesel
Wind energy: uses moving mass of wind (kinetic energy) to create electrical energy (dependent on speed and density, compare with tidal)
Solar: Three types-PV (photovoltaic), ST (solar thermal), and CSP (concentrated solar power)
Storage is the issue. Passive solar uses heat density to flow, active solar has a pump.
Hydropower uses mass of water with height (PE = Mgh) or flow (tidal). Best is lots of mass and lots of height, e.g. not Nebraska.
Geothermal: heat from Uranium fission reactions in the earth core, transferred by convection to the surface.
Geothermal can be closed cycle or open cycle, usually using injection. See also steam capture (like Iceland)
Fuel cells use the H + O = water reaction forward and reverse. To make Hydrogen, use an electrolyzer, then use the Hydrogen in a fuel cell to create DC electrical energy. Not very efficient, unless you capture the heat.
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