CEM Concepts and Principles 2 — Questions and Answers
Question 1: What does the term 'demand charge' refer to on a commercial electricity bill?
- The cost per kWh of electricity consumed
- A fee based on the peak power demand during the billing period (Correct answer)
- A surcharge for exceeding contracted energy volume
- The fixed monthly service charge from the utility
Correct answer: A fee based on the peak power demand during the billing period
Demand charges are billed based on the highest 15- or 30-minute average power draw (kW) recorded during the billing period.
Question 2: In energy management, what is 'baseload'?
- The maximum energy demand recorded in a year
- The minimum level of energy consumption maintained continuously (Correct answer)
- The average of peak and off-peak loads
- Energy consumed only during business hours
Correct answer: The minimum level of energy consumption maintained continuously
Baseload is the minimum power requirement a facility maintains around the clock, representing constant, uninterruptible energy use.
Question 3: Which metric best describes how effectively a facility converts input energy into useful output?
- Power factor
- Energy intensity
- Energy efficiency (Correct answer)
- Load factor
Correct answer: Energy efficiency
Energy efficiency is the ratio of useful energy output to total energy input, indicating how well energy is converted to productive work.
Question 4: What is the primary purpose of a Measurement & Verification (M&V) plan in an energy project?
- To estimate future utility rates
- To document and verify energy savings achieved after implementation (Correct answer)
- To set energy reduction targets for the next fiscal year
- To audit contractor invoices for capital equipment
Correct answer: To document and verify energy savings achieved after implementation
An M&V plan establishes the methodology for measuring actual energy performance and verifying that projected savings are realized.
Question 5: The International Performance Measurement and Verification Protocol (IPMVP) Option A is best described as:
- Whole-facility metering with no stipulated parameters
- Key parameter measurement with stipulation of other parameters (Correct answer)
- Calibrated simulation of the entire building
- Retrofit isolation using short-term spot measurements only
Correct answer: Key parameter measurement with stipulation of other parameters
IPMVP Option A measures key performance parameters while stipulating (assuming) values for less significant parameters to reduce measurement cost.
Question 6: Which of the following best defines 'energy conservation' as distinct from 'energy efficiency'?
- Using higher-efficiency equipment to deliver the same service
- Reducing energy use by modifying behavior or curtailing services (Correct answer)
- Switching from fossil fuels to renewable energy sources
- Implementing automated controls to optimize equipment schedules
Correct answer: Reducing energy use by modifying behavior or curtailing services
Energy conservation involves reducing consumption by changing behavior or accepting reduced service levels, whereas efficiency delivers the same service with less energy.
Question 7: What is 'specific energy consumption' (SEC) used to measure in industrial energy management?
- Total facility energy use in BTUs per year
- Energy used per unit of production output (Correct answer)
- The ratio of electricity to fuel usage
- Peak demand divided by annual operating hours
Correct answer: Energy used per unit of production output
SEC normalizes energy consumption against production volume, allowing fair comparison of efficiency across different output levels.
CEM Concepts and Principles 2
What does the term 'demand charge' refer to on a commercial electricity bill?