Do Now: Energy Move Clip Answer the following questions in your notebook. 1) What is energy? 2) List 4 types of energy from the clip.

Aim: How is energy wasted?

Case Study: A Brief History of Human Energy Use Everything runs on energy Industrial revolution began 275 years ago, relied on wood… led to deforestation Today we rely on: - Coal - Petroleum products - Natural gas

Why do you think the world as a whole relies more on renewable energy than the U.S. does? Fig. 15-1, p. 370

Net Energy Is the Only Energy That Really Counts First law of thermodynamics: – It takes high-quality energy to get high-quality energy – Ex: Pumping oil from ground, refining it, transporting it Second law of thermodynamics – Some high-quality energy is wasted at every step

Do you understand the 2 laws of thermodynamics?

It Takes Energy to Pump Petroleum Fig. 15-2, p. 372

Pumping Petroleum Movie Clip How do we get oil from the ground?

Net Energy Is the Only Energy That Really Counts Net energy – Total amount of useful energy available from a resource minus the energy needed to make the energy available to consumers

Net Energy Ratio Ratio of energy produced to energy used to produce it. Conventional oil: high net energy ratio

Do you understand net energy?

Net Energy Ratios Fig. 15-3, p. 373

Fig. 15-3a, p. 373 Space Heating Passive solar5.8 Natural gas4.9 Oil4.5 Active solar 1.9 Coal gasification 1.5 Electric heating (coal-fired plant) 0.4 Electric heating (natural-gas-fired plant) 0.4 Electric heating (nuclear plant) 0.3

Fig. 15-3b, p. 373 High-Temperature Industrial Heat Surface-mined coal 28.2 Underground- mined coal 25.8 Natural gas 4.9 Oil 4.7 Coal gasification 1.5 Direct solar (concentrated) 0.9

Fig. 15-3c, p. 373 Transportation Natural gas4.9 Gasoline (refined crude oil) 4.1 Biofuel (ethanol)1.9 Coal liquefaction1.4 Oil shale1.2

Do you understand the net energy ratio?

Energy Resources With Low/Negative Net Energy Yields Need Marketplace Help Cannot compete in open markets with alternatives that have higher net energy yields Need subsidies from taxpayers…Is this good or bad? Nuclear power as an example

Reducing Energy Waste Improves Net Energy 84% of all commercial energy used in the U.S. is wasted – 43% after accounting for second law of thermodynamics Drive efficient cars, not gas guzzlers Make buildings energy efficient

Summary: Typical citizens of advanced industrialized nations each consume as much energy in 6 months as typical citizens in less developed countries consume during their entire life. Why is this? Will this ever change?