CEA Data Analysis & Reporting 3 — Questions and Answers
Question 1: An energy analyst discovers that a facility's load factor is 0.45. This means:
- The facility operates at 45% efficiency
- Average demand is 45% of peak demand over the billing period (Correct answer)
- 45% of energy is lost to heat
- The power factor is 0.45
Correct answer: Average demand is 45% of peak demand over the billing period
Load factor = Average Demand ÷ Peak Demand; a value of 0.45 means average consumption is 45% of the peak, indicating significant demand variability and opportunity for load leveling.
Question 2: Which data visualization method is best for identifying patterns and anomalies in hourly energy consumption across an entire year?
- Annual summary table
- Heat map (calendar or time-of-day matrix) (Correct answer)
- Single-line trend chart
- Bar chart of monthly totals
Correct answer: Heat map (calendar or time-of-day matrix)
Heat maps display hourly energy data across days or months simultaneously, making it easy to visually spot recurring patterns, anomalies, and occupancy-related consumption spikes.
Question 3: In energy reporting, what is the primary purpose of an Energy Performance Indicator (EnPI)?
- To set the utility billing rate for the facility
- To quantify energy consumption relative to a relevant variable like production or area (Correct answer)
- To calculate the carbon footprint of the organization
- To determine peak demand charges on utility bills
Correct answer: To quantify energy consumption relative to a relevant variable like production or area
An EnPI normalizes energy consumption against a relevant variable (e.g., BTU/unit produced), enabling meaningful performance tracking independent of changes in output or occupancy.
Question 4: A facility uses 500,000 kWh/year and installs LED lighting expected to save 20%. What is the annual energy savings in kWh?
- 20,000 kWh
- 50,000 kWh
- 100,000 kWh (Correct answer)
- 200,000 kWh
Correct answer: 100,000 kWh
500,000 kWh × 0.20 = 100,000 kWh annual savings; this straightforward percentage calculation is fundamental to energy audit reporting.
Question 5: When performing interval data analysis, 15-minute demand data is primarily used to:
- Calculate annual carbon emissions
- Identify demand peaks and opportunities to reduce peak demand charges (Correct answer)
- Verify meter accuracy against nameplate ratings
- Determine seasonal energy price adjustments
Correct answer: Identify demand peaks and opportunities to reduce peak demand charges
15-minute interval data reveals demand peaks that drive utility demand charges, allowing analysts to identify load-shifting or peak-shaving opportunities that reduce costs.
Question 6: What is the purpose of a cumulative sum (CUSUM) chart in energy monitoring?
- To display monthly utility costs over time
- To detect sustained shifts in energy performance relative to a baseline model (Correct answer)
- To compare energy costs between different facilities
- To calculate the payback period for retrofits
Correct answer: To detect sustained shifts in energy performance relative to a baseline model
CUSUM charts accumulate deviations from a baseline model over time, making sustained performance changes—either improvements or degradations—clearly visible even when individual deviations are small.
Question 7: Which factor should an energy analyst adjust for when comparing a school's energy consumption between a school year and summer break?
- Utility rate changes
- Occupancy hours and operational schedule (Correct answer)
- Equipment depreciation
- Carbon offset credits
Correct answer: Occupancy hours and operational schedule
Occupancy hours and operational schedule dramatically affect school energy use; comparing periods without this adjustment produces misleading conclusions about efficiency performance.
CEA Data Analysis & Reporting 3
An energy analyst discovers that a facility's load factor is 0.45.
This means: