AP Environmental Science
apes week 2.1
energy->water->food->culture
units: Joule = work or energy
kJ = 1000 J
4.18 J = 1 cal
1 kcal = 1000 cal = 1 Cal (food calorie, note the capital letter)
electricity units:
1 joule/second = 1 Watt (capital again, named after James Watt)
1 kW = 1000 W, or about the power used to run a toaster
energy is like amount of water (gallons, liters)
power is like flow (gal/minute, liters/second)
Try these:
100W bulb runs for 3 hours = 0.3 kWh
Huh? another unit?
Yes, power people are not so complex, so instead of using Joules (like they do in much of the world), we take an energy unit (Joules) divided by time (seconds), then multiply by time again (hours) to get energy. Pretty dumb.
Another calculation:
1.5 kW toaster runs for 2 hours. Electricity costs $0.50 per kWh. How much does this cost?
1.5 kW x 2 hours = 3 kWh, 3 kWh x $0.50 = $1.50
This really adds up if you have a 4.5 kW water heater running for 2 hours per day. How much would this cost?
Back to energy:
In the US, energy is used for three things:
1/3 transport (usually using oil-gasoline or diesel)
1/3 buildings (nat gas, heating oil, electricity from coal/nat gas)
1/3 industry (same as above, more electricity though)
How can we change this?
Industry: factories, machines, pumps, furnaces
Nat gas instead of coal for electricity. Why?
Coal mining, air pollution, water pollution, heavy metals, coal ash, CO2.
Nat gas (methane, propane, butane, pentane etc.) has lower CO2 per Joule, lower Hg, no ash, no water pollution.
If it comes from fracking, then we have another issue (water pollution, toxic waste)
Transport: moving stuff around (cars, trucks, trains, airplanes)
hybrid/electric vehicles, nat gas for trucking and train fleets (see same reasons as above).
question: why are electric trains so much more efficient?
Buildings: heating and cooling.
HVAC systems (Heating, Ventilation And Cooling) or heating/ventilation/air conditioning, depending on who you ask.
Very energy intensive, dependent on set points (thermostat), humidity, insulation, and air flow (ACH means something, look this up).
Conservation = 8x production $
Three phases of campus energy overhaul:
conservation/monitoring+harvesting+storage
One very rich dude bought up all of the trains in the US a few years ago, at the same time he bought up much of the natural gas resources. Why would he do this?
Another very rich oil dude sold all of his oil holdings and created huge networks of wind farms in Texas. Why would he do this? How old were these dudes? Why does this matter?
e2 Videos: (20 minutes each)
Harvesting the wind: community wind power in Minnesota
Energy for a developing world: solar power in Bangladesh
Paving the way: next generation cars
Growing energy: bioethanol in Brazil
State of resolve: California cars
Coal and nuclear: Next generation nuclear, coal
Heat video (recall the melting glaciers) (120 minutes)
ERoEI video (9 minutes)-connect the dots with Hydrogen as an energy carrier (wind->H2 for transport)
Peak Resources video (15 minutes) (from Crash course)
China Syndrome event
Hubbert Peak-graphic
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