CEA Data Analysis & Reporting 2 — Questions and Answers
Question 1: When normalizing energy consumption data for weather variations, which metric is most commonly used?
- Relative humidity index
- Degree days (heating and cooling) (Correct answer)
- Wind chill factor
- Solar radiation index
Correct answer: Degree days (heating and cooling)
Degree days (heating and cooling) are the standard metric for weather-normalizing energy consumption, allowing meaningful comparisons across different climate periods.
Question 2: A facility's energy intensity is best expressed as:
- Total kWh consumed per year
- BTU per square foot per year (Correct answer)
- Peak demand in kW
- Monthly utility cost in dollars
Correct answer: BTU per square foot per year
Energy intensity expressed as BTU per square foot per year normalizes consumption by building size, enabling meaningful benchmarking against similar facilities.
Question 3: Which statistical technique is used to identify the relationship between energy consumption and production output in a manufacturing facility?
- Chi-square test
- Linear regression analysis (Correct answer)
- Pareto analysis
- Monte Carlo simulation
Correct answer: Linear regression analysis
Linear regression analysis quantifies the relationship between energy consumption (dependent variable) and production output (independent variable), producing an Energy Performance Indicator.
Question 4: In an energy audit report, the Simple Payback Period (SPP) is calculated as:
- Annual energy savings divided by implementation cost
- Implementation cost divided by annual energy savings (Correct answer)
- Net present value divided by discount rate
- Annual energy savings multiplied by project life
Correct answer: Implementation cost divided by annual energy savings
SPP = Implementation Cost ÷ Annual Energy Savings, giving the number of years required to recover the initial investment through energy cost reductions.
Question 5: What does a coefficient of variation (CV) in energy data analysis primarily indicate?
- The trend direction of energy use over time
- The relative variability or dispersion of data around the mean (Correct answer)
- The correlation between two energy variables
- The seasonal adjustment factor for consumption
Correct answer: The relative variability or dispersion of data around the mean
The coefficient of variation (CV = standard deviation / mean) indicates the relative dispersion of data, helping analysts assess data reliability and identify anomalous readings.
Question 6: Which chart type is most appropriate for displaying the distribution of a facility's energy end-uses by percentage?
- Scatter plot
- Pie chart or stacked bar chart (Correct answer)
- Control chart
- Histogram
Correct answer: Pie chart or stacked bar chart
Pie charts and stacked bar charts effectively display proportional breakdowns of energy end-uses, making it easy to identify the largest consumption categories.
Question 7: When reporting energy savings from an Measurement & Verification (M&V) plan, the baseline period must:
- Cover at least five years of historical data
- Represent normal operating conditions before the efficiency measure (Correct answer)
- Be adjusted for future production forecasts
- Exclude any months with equipment downtime
Correct answer: Represent normal operating conditions before the efficiency measure
Per IPMVP protocols, the baseline must represent typical operating conditions prior to implementing the energy conservation measure, ensuring valid savings comparisons.
CEA Data Analysis & Reporting 2
When normalizing energy consumption data for weather variations, which metric is most commonly used?