Certified Energy Auditor Certification Energy Audit Data Analysis 5 â Questions and Answers
Question 1: An energy auditor is performing a Level II audit and finds 15-minute interval electricity data shows demand spikes lasting only 1-2 intervals. What is the most cost-effective first step to address this?
- Install a large battery energy storage system to shave all peaks
- Investigate whether the spikes are caused by equipment with staggered start sequencing that could be adjusted (Correct answer)
- Upgrade the utility service to a higher demand tier to reduce penalty rates
- Install a power factor correction capacitor bank at the main panel
Correct answer: Investigate whether the spikes are caused by equipment with staggered start sequencing that could be adjusted
Short-duration demand spikes often result from simultaneous equipment startups; staggering starts through controls or timers can eliminate spikes at minimal cost before capital solutions are considered.
Question 2: When calculating the internal rate of return (IRR) for an energy project, what does it mean if the IRR equals the organization's minimum acceptable rate of return (MARR)?
- The project generates exactly the minimum required return and is at the threshold of acceptability (Correct answer)
- The project will generate twice the required return and should be prioritized
- The project's NPV is positive and it should be approved immediately
- The project payback period equals the project lifetime in years
Correct answer: The project generates exactly the minimum required return and is at the threshold of acceptability
When IRR equals MARR, NPV equals zeroâthe project just meets the minimum financial hurdle and the decision is at the breakeven point of acceptability.
Question 3: An auditor discovers that a manufacturing facility's energy consumption per unit of production has increased 12% over three years despite no equipment changes. What analysis should be performed?
- Re-baseline the facility using the most recent year's data to remove the anomaly
- Analyze production mix, shift patterns, equipment loading factors, and maintenance records for the period (Correct answer)
- Attribute the increase to inflation in utility rates and exclude it from the audit findings
- Recommend replacing all major process equipment with higher-efficiency alternatives
Correct answer: Analyze production mix, shift patterns, equipment loading factors, and maintenance records for the period
An unexplained efficiency decline over time requires root cause analysis across operational factorsâproduction mix changes, reduced throughput, deferred maintenance, or process changesâbefore conclusions are drawn.
Question 4: What is the primary distinction between 'gross savings' and 'net savings' in energy audit reporting?
- Gross savings are measured; net savings are calculated from engineering estimates
- Net savings account for free-rider effects and spillover, while gross savings reflect total measured savings (Correct answer)
- Gross savings exclude utility rebates; net savings include all financial incentives
- Net savings are adjusted for inflation; gross savings use current energy prices
Correct answer: Net savings account for free-rider effects and spillover, while gross savings reflect total measured savings
Gross savings are the total energy reduction attributed to a measure; net savings adjust for free riders (who would have acted without incentive) and spillover effects in program evaluation contexts.
Question 5: An auditor analyzes a steam trap survey and finds that 30% of traps are failed-open (blowing live steam). How should this finding be quantified for the audit report?
- Report the number of failed traps as a percentage and recommend annual survey
- Calculate steam loss per trap using known failure mode flow rates, convert to fuel cost, and project annual savings from repair (Correct answer)
- Estimate repair cost only, since steam loss is difficult to quantify without flow meters
- Flag as a safety issue and defer energy savings calculation to a mechanical engineer
Correct answer: Calculate steam loss per trap using known failure mode flow rates, convert to fuel cost, and project annual savings from repair
Failed-open traps have known steam loss rates by trap orifice size and pressure; converting steam loss to boiler fuel consumption and applying fuel cost yields a quantifiable annual savings for the audit report.
Question 6: A building energy model predicts 18% annual energy savings from a proposed HVAC upgrade. Which factor would most reduce confidence in this prediction?
- The model was calibrated to within 15% of actual annual consumption
- The model uses TMY (Typical Meteorological Year) weather data instead of actual historical weather
- Occupancy schedules in the model were estimated rather than measured (Correct answer)
- The model was built using simulation software not on ASHRAE's approved list
Correct answer: Occupancy schedules in the model were estimated rather than measured
Occupancy schedules directly drive HVAC loads; if schedules are estimated rather than measured (via occupancy sensors or badge data), predicted savings can deviate significantly from actual post-retrofit performance.
Question 7: When reporting energy audit findings to facility management, which financial metric is most useful for comparing projects with different lifetimes and investment sizes?
- Simple payback period
- Net present value (NPV) (Correct answer)
- First-year energy cost savings in dollars
- Total lifetime energy saved in kBtu
Correct answer: Net present value (NPV)
NPV normalizes cash flows over the project lifetime and accounts for the time value of money, enabling valid comparison of projects with different scales, lifetimes, and cash flow profiles.
Certified Energy Auditor Certification Energy Audit Data Analysis 5
An energy auditor is performing a Level II audit and finds 15-minute interval electricity data shows demand spikes lasting only 1-2 intervals.
What is the most cost-effective first step to address this?