CEA Data Analysis & Reporting 4 ā Questions and Answers
Question 1: In a scatter plot of energy use versus outdoor air temperature, a strong positive correlation during summer months most likely indicates:
- Excessive heating system operation
- Significant cooling load driven by outdoor temperature (Correct answer)
- Lighting energy proportional to daylight hours
- Baseload equipment cycling issues
Correct answer: Significant cooling load driven by outdoor temperature
A positive correlation between energy use and outdoor temperature in summer indicates that cooling loadsādriven by HVAC systems responding to heatāare a major energy driver.
Question 2: What does the term 'baseload' refer to in energy data analysis?
- The peak electricity demand during the highest demand month
- The minimum energy consumption that occurs regardless of weather or production (Correct answer)
- The energy used exclusively for heating and cooling
- The utility's base electricity rate before tiered pricing
Correct answer: The minimum energy consumption that occurs regardless of weather or production
Baseload is the minimum energy consumption level that persists regardless of weather or production changes, typically representing always-on equipment like servers, refrigeration, and lighting.
Question 3: An energy analyst is comparing two buildings using Energy Star Portfolio Manager. The primary output metric is:
- Total annual kWh consumption
- Energy Star score (1ā100) based on source energy intensity (Correct answer)
- Monthly utility cost per occupant
- Peak demand kW per square foot
Correct answer: Energy Star score (1ā100) based on source energy intensity
Energy Star Portfolio Manager generates a 1ā100 score based on source energy use intensity compared to similar buildings nationally, where 50 is median and 75+ qualifies for certification.
Question 4: When an energy report shows a facility's greenhouse gas (GHG) emissions in CO2e, the 'e' stands for:
- Estimated
- Equivalent (Correct answer)
- Emitted
- Elemental
Correct answer: Equivalent
CO2e (carbon dioxide equivalent) converts all greenhouse gases to their warming potential relative to CO2, allowing different GHGs to be expressed in a single comparable unit.
Question 5: An energy analyst uses an OLS regression model with RĀ² = 0.92. What does this indicate?
- The model has 92 data points in the dataset
- 92% of the variance in energy consumption is explained by the independent variable(s) (Correct answer)
- The model has 8% error in its energy savings projections
- Energy costs will decrease by 92% after implementing recommendations
Correct answer: 92% of the variance in energy consumption is explained by the independent variable(s)
RĀ² = 0.92 means 92% of the variation in energy consumption is explained by the model's independent variables, indicating a strong and reliable predictive relationship.
Question 6: Which of the following best describes 'source energy' as used in building energy benchmarking?
- Energy generated on-site by solar panels or CHP systems
- Total energy required to generate and deliver the energy used at the site, including generation and transmission losses (Correct answer)
- Energy consumed only by primary HVAC systems
- The energy content of fuel before combustion inefficiencies
Correct answer: Total energy required to generate and deliver the energy used at the site, including generation and transmission losses
Source energy accounts for all energy used to generate, transmit, and deliver energy to the building, providing a complete picture of total resource consumption including utility-side losses.
Question 7: A facility manager asks for a report showing which energy conservation measures (ECMs) to prioritize. Which analysis framework ranks ECMs by cost-effectiveness?
- SWOT analysis
- Cost-benefit ranking with payback period and NPV (Correct answer)
- Failure mode and effects analysis (FMEA)
- Process flow diagram
Correct answer: Cost-benefit ranking with payback period and NPV
Ranking ECMs by payback period and net present value (NPV) allows decision-makers to prioritize investments that offer the greatest financial return relative to implementation cost.
CEA Data Analysis & Reporting 4
In a scatter plot of energy use versus outdoor air temperature, a strong positive correlation during summer months most likely indicates: