Total World Energy

ENGR40

Foothill College

Energy in Terawatts (TW)

http://en.wikipedia.org/wiki/File:World_Energy_consumption.png

What can we know from this info-graphic?

• Total energy in quads– Convert terawatt to watt-second to joules to

BTU (write it out and use all your units!)

• Total ‘mass’ of each fuel type– Coal ~10,000 BTU/pound– Petroleum is ~5.8M BTU/barrel– Gas is 100,000 BTU/ cubic foot

• Total emissions from each fuel type– Work back to mass of carbon => CO2

Working in Terawatts

• Convert TW to tWh => multiply by 8760

• Convert tWh to kWh (divide watts/1000)

• Convert kWh to BTU (multiply by 3412)

• Terawatts is not that tricky (it is a RATE of energy use) and shows total energy trends

• If we are 15TW today (2011) how many Quads is that? What about in 2035-2050?

• Think about energy efficiency as a lever…

Converting to GHGs

• Convert BTU to pounds of carbon coal (10,000 BTU/pound) then correct for C:H (85:15) then multiply by 3.7 pounds CO2 per pound carbon

• Convert BTU petroleum to barrels (~5.8M BTU/barrel) then ~7 pounds (-CH2-) per gallon. Convert to moles (or correct for C/H ratio CH2)

• Natural gas is 1020 BTU/cubic foot and 1.26 moles per cubic foot. Convert Quads => moles CH4 = moles CO2. convert to pounds/tons

• Hint: one mole CO2 is roughly 0.1 pounds CO2

Working with info-graphics

• One picture can be worth 1,000 data points, especially if it is a trending graphic

• Try to calculate numbers from data points, see if the data are ‘internally consistent’.

• What other things can you learn from a graph? (We calculated quads and GHGs)

• Can you project the future, or ‘federate’ with other data (global/capita GDP, and energy use). What will the future look like?