CEM Certified Energy Manager Audit & Billing 3 — Questions and Answers
Question 1: When comparing energy performance across multiple facilities, a CEM should normalize consumption data to account for:
- Utility rate schedules
- Weather variations and occupancy differences (Correct answer)
- Billing cycle length only
- Meter reading errors
Correct answer: Weather variations and occupancy differences
Normalization for weather (heating/cooling degree days) and occupancy ensures valid comparisons across dissimilar facilities and time periods.
Question 2: A facility's Energy Use Intensity (EUI) is calculated as:
- Annual energy cost divided by square footage
- Annual energy consumption (kBtu) divided by gross floor area (sq ft) (Correct answer)
- Peak demand (kW) divided by occupancy hours
- Monthly kWh divided by number of employees
Correct answer: Annual energy consumption (kBtu) divided by gross floor area (sq ft)
EUI equals total annual energy use in kBtu divided by gross floor area in square feet, enabling benchmarking across similar building types.
Question 3: Which document should a CEM review FIRST when beginning a billing analysis for a commercial facility?
- Equipment maintenance logs
- Utility tariff schedules and rate structures (Correct answer)
- Building floor plans
- HVAC equipment specifications
Correct answer: Utility tariff schedules and rate structures
Understanding the applicable tariff and rate structure is essential before analyzing any billing data, as rates determine cost drivers.
Question 4: A facility is on a Time-of-Use (TOU) rate. Operations want to run a 500 kW chiller. To minimize costs, it should preferably operate during:
- On-peak hours (typically 12–6 PM weekdays)
- Off-peak hours (nights and weekends) (Correct answer)
- Super-peak hours
- Shoulder periods only
Correct answer: Off-peak hours (nights and weekends)
Off-peak hours have the lowest energy and demand rates under TOU schedules, minimizing operating costs for large loads.
Question 5: What is the purpose of a baseline energy model in an energy audit?
- To project future utility rate increases
- To establish pre-retrofit energy consumption for savings verification (Correct answer)
- To calculate power factor correction needs
- To size replacement equipment
Correct answer: To establish pre-retrofit energy consumption for savings verification
The baseline model represents pre-retrofit conditions against which post-retrofit performance is compared to verify energy savings.
Question 6: A CEM reviews 24 months of utility data and finds consumption in months 13–24 is 12% higher than months 1–12 despite no operational changes. The MOST likely cause is:
- Meter calibration drift
- Rate schedule change by the utility
- Increased equipment runtime due to aging (Correct answer)
- Weather normalization error
Correct answer: Increased equipment runtime due to aging
Aging equipment typically loses efficiency over time, causing increased energy consumption even with constant operational schedules.
Question 7: Coincident demand charges are based on a customer's demand during:
- Their own facility's peak demand hour
- The utility system's peak demand period (Correct answer)
- The highest 15-minute interval of the month
- Business hours only, regardless of grid conditions
Correct answer: The utility system's peak demand period
Coincident demand is the customer's load measured specifically during the utility system's peak period, often used by wholesale utilities.
CEM Certified Energy Manager Audit & Billing 3
When comparing energy performance across multiple facilities, a CEM should normalize consumption data to account for: