Lesson 13.1 — Energy Efficiency Worksheet

Section 1 — Key Vocabulary

SEP 8 pp. 425–433

1. Define each term in your own words. Do not copy sentences directly from the text.

Energy Efficiency

Cogeneration

Hydrogen Fuel Cell

Net Zero Energy Building

2. The text compares an LED bulb to an incandescent bulb to illustrate energy efficiency. Describe one other example from the reading that shows a difference in energy efficiency. Explain what makes one option more efficient than the other.

Section 2 — Multiple Choice

SEP 8 pp. 425–429

3. According to Figure 13-2, approximately what percentage of U.S. commercial energy actually performs useful work?

A. 84% B. 62% C. 38% D. 16%

4. Why does a typical car engine waste most of the energy from burning gasoline?

A. Gasoline contains too little chemical energy to move a vehicle efficiently B. Only about 20% of the energy from burning gasoline moves the car; the rest escapes as waste heat C. Suburban drivers tend to speed, which reduces engine efficiency D. Electric motors in the car consume most of the fuel before it reaches the engine

5. Cogeneration improves energy efficiency by:

A. Using two separate fuel sources to generate one form of energy B. Capturing waste steam from power generation and reusing it to heat buildings C. Replacing coal plants with solar panels on factory rooftops D. Running industrial motors at full speed to maximize output

6. Which of the following is NOT listed as a benefit of improving energy efficiency?

A. Reduces oil imports and improves energy security B. Creates jobs and saves consumers money C. Eliminates all greenhouse gas emissions from transportation D. Reduces pollution and helps slow climate change

Section 3 — Data Analysis: U.S. Commercial Energy Flow

SEP 4 Figure 13-2, p. 425

Figure 13-2 — Key Data
Nonrenewable fossil fuels (input)	79%
Nonrenewable nuclear (input)	9%
Renewable energy (input)	12%
Useful energy produced (output)	30%
Petrochemicals produced (output)	8%
Rejected / wasted energy (output)	62%

7. Using the data above, calculate the total percentage of energy that is not performing useful work (rejected + petrochemicals). Show your math.

8. The text states that 41% of energy waste is unavoidable (Second Law of Thermodynamics), while 43% is wasted due to inefficient devices and systems. What does this suggest about where humans have the greatest opportunity to improve? Use the data to support your answer.

Section 4 — Short Answer: Sectors & Strategies

SEP 6 pp. 426–432

9. Industry: Describe two specific strategies from the reading that industries can use to improve energy efficiency. For each, briefly explain how it saves energy.

10. Transportation: The "true price" of gasoline is higher than what you pay at the pump. List at least three hidden costs described in the text, then explain how higher gas taxes could address this problem.

11. Buildings: Identify two specific features of green architecture described in the reading and explain how each one reduces energy use in a building.

12. Smart Grid: What is a smart grid, and why is the current U.S. electrical grid considered an energy efficiency problem? Describe two improvements the smart grid would make.

Section 5 — Claim · Evidence · Reasoning

SEP 7 pp. 427–428

13. Prompt: Should the U.S. government require all new passenger vehicles to meet a fuel economy standard of 43 kpl (100 mpg) by 2040? Use specific evidence from the reading to support your position.

Claim
Evidence (specific data or facts)
Reasoning (connect to your claim)

Section 6 — Application & Synthesis

SEP 6 pp. 425–432

14. According to a DOE study, replacing most U.S. vehicles with plug-in hybrids recharged by renewable energy would cut CO₂ emissions by 80–90%. Identify two other specific changes this shift would cause in the U.S. energy system. For each, explain whether it is a benefit or a trade-off and why.