REP Energy Efficiency and Demand-Side Management 2 — Questions and Answers
Question 1: What is the purpose of an energy audit in a commercial facility?
- To verify that a facility's renewable energy certificates are valid
- To identify opportunities to reduce energy consumption and improve operational efficiency (Correct answer)
- To calculate the facility's carbon offset credits for trading
- To confirm compliance with local building permits
Correct answer: To identify opportunities to reduce energy consumption and improve operational efficiency
An energy audit systematically reviews a facility's energy use to identify inefficiencies and recommend cost-effective improvements.
Question 2: The ENERGY STAR program, administered by the U.S. EPA and DOE, certifies products and buildings that:
- Use at least 50% renewable energy in their operation
- Meet strict energy efficiency performance standards set above the minimum code requirements (Correct answer)
- Are manufactured using sustainable and recycled materials
- Generate more energy than they consume on an annual basis
Correct answer: Meet strict energy efficiency performance standards set above the minimum code requirements
ENERGY STAR certification indicates that a product or building performs in the top tier of energy efficiency compared to similar models or buildings, exceeding baseline code requirements.
Question 3: Which of the following technologies is most directly associated with demand-side management by enabling automated control of home appliances based on grid signals?
- Concentrating solar power (CSP) mirrors
- Smart thermostats and home energy management systems (HEMS) (Correct answer)
- Variable-speed wind turbine generators
- Underground pumped hydro storage
Correct answer: Smart thermostats and home energy management systems (HEMS)
Smart thermostats and HEMS respond to utility price signals or direct load control commands, automatically adjusting appliance operation to reduce peak demand.
Question 4: What is the difference between energy conservation and energy efficiency?
- Conservation means switching to renewables; efficiency means reducing fossil fuel use
- Conservation involves behavioral changes to use less energy; efficiency achieves the same output with less energy input (Correct answer)
- Efficiency focuses on generation; conservation focuses on transmission losses
- They are interchangeable terms with no meaningful distinction
Correct answer: Conservation involves behavioral changes to use less energy; efficiency achieves the same output with less energy input
Energy conservation refers to using less energy through behavioral changes (e.g., turning off lights), while energy efficiency means accomplishing the same task using less energy through improved technology or design.
Question 5: A building owner installs LED lighting to replace incandescent bulbs. Which of the following best describes this action from an energy efficiency perspective?
- Demand response, because the owner reduced load during a peak event
- Energy efficiency improvement, because the same lighting level is maintained with significantly less electricity (Correct answer)
- Fuel switching, because the energy source changed from thermal to electrical
- Load shifting, because lighting use was moved to off-peak hours
Correct answer: Energy efficiency improvement, because the same lighting level is maintained with significantly less electricity
Replacing incandescent bulbs with LEDs delivers equivalent or better illumination while consuming up to 75% less electricity, which is a classic energy efficiency measure.
Question 6: In the context of green building certifications in the U.S., which rating system awards points for both energy efficiency measures and on-site renewable energy generation?
- ISO 14001
- LEED (Leadership in Energy and Environmental Design) (Correct answer)
- OSHA 1926
- IEEE 1547
Correct answer: LEED (Leadership in Energy and Environmental Design)
LEED, developed by the U.S. Green Building Council, is the most widely used green building rating system and awards credits for energy performance, renewable energy use, water efficiency, and other sustainability categories.
Question 7: What is 'load factor' in electrical systems, and why is it important for energy efficiency?
- The ratio of actual energy produced to the nameplate capacity of a generator; higher is always better for consumers
- The ratio of average load to peak load over a time period; a higher load factor indicates more consistent and efficient use of electrical infrastructure (Correct answer)
- The percentage of electricity lost during transmission; lower percentages mean better grid efficiency
- The number of hours per day a facility operates at full capacity; always measured over a 24-hour period
Correct answer: The ratio of average load to peak load over a time period; a higher load factor indicates more consistent and efficient use of electrical infrastructure
Load factor (average load ÷ peak load) reflects how consistently electrical infrastructure is used; a higher load factor means demand is steadier, reducing the need for expensive peaking capacity and improving economic efficiency.
REP Energy Efficiency and Demand-Side Management 2
What is the purpose of an energy audit in a commercial facility?