Diagnosing the energy system and sustainability boundaries

Review questions

From service balance to strategic diagnosis

Start a transition decision with the service that must continue: its quantity, quality, timing and interruption limits. Then follow energy from the meter to useful output. In the boiler case, omitting distribution losses and auxiliaries understated electricity demand. The annual balance also failed to establish sufficient connection capacity during the peak hour. A fair technology comparison preserves service and measurement boundaries before ranking alternatives.

An emissions inventory describes a declared boundary and accounting method; project impact requires a counterfactual. Purchasing steam can lower scope 1 while moving most emissions into scope 2. The supplier factor could reverse the worked case from a reduction to an increase, making data quality a decision condition. Lower intensity likewise establishes neither lower total emissions nor a particular project's causal effect.

Test strategy against conditional futures rather than treating one scenario as a forecast. Minimax regret can select a different alternative from the one with the greatest upside, while a strict downside condition may exclude an option before ranking. Unsupported probabilities do not create precision. Calculate the switching threshold and identify an observable signal that justifies updating the assumption.

Service, water and emissions constraints precede weighted comparison. Withdrawn water differs from consumed water, and annual totals can hide seasonal stress. In the cooling case, low cost could not compensate for violating a binding condition. When every alternative fails, redesign the package rather than change weights to conceal failure.

Finish with a testable diagnosis. The electricity company's mix improved while fossil conversion efficiency stayed constant and total emissions rose. The data supported neither the efficiency narrative nor the claim that no progress occurred. A defensible recommendation connects each alternative to a decisive assumption, a performance or displacement test and a decision date. Preserve the distinction between calculation, measurement, conditional inference and unresolved evidence.

Review questions

Test your understanding with these questions. Marking and saved results are available with a free account.

Question 1What is fuel input? 38,880 60,000 75,000 67,500
Question 2Constant-intensity baseline gives48,000. What does the3,000 difference establish? A normalized difference, not proof of intervention causation alone Absolute reduction3,000 from prior year Current emissions48,000 Certain causal maintenance impact
Question 3What good-state probability equalizes expected values? 0.50 0.70 0.4167 Approximately0.5833
Question 4What is consumption in this simplified balance? 100 m³ 30 m³ 70 m³ 170 m³
Question 5What is conversion efficiency? 45% 250% 40% 60%
Question 6At new output13,200, what are same-output savings? 2,112 1,920 1,152 12,560
Question 7A heat pump uses3,200 MWh with35 thousand maintenance. What electricity price equalizes operation? 131.25 109.375 142.1875 120.3125
Question 8What electricity recharges it? 17.10 Approximately21.0526 20.00 18.95
Question 9Does lower electricity use by a heater establish substitution? Yes, all energy is functionally interchangeable Yes, electricity is always emission-free No; compare the chemical function and required service No technical alternative can be evaluated
Question 10What is wrong? The package is infeasible because alternatives cannot coexist Addition is valid if both values are positive Simply remove one cost Rename an asset to resolve exclusion
Question 11How does it enter incremental cash flow? Annual expense100 thousand Ignore because it is recovered Positive100 thousand now, negative year5 Negative100 thousand now, positive year5 discounted
Question 12What is equivalent annual cost? −120,000 Approximately148,252 Approximately268,252 Approximately508,252
Question 13What is its proper use? Official next-year price forecast Guaranteed profit above it regardless of other inputs A decision threshold conditional on other assumptions Evidence the market will reach it
Question 14What is cost per used unit? Approximately73.33 60 55 Approximately86.67
Question 15Immediate investment value1.5; instant perfect-information value3.3. What is maximum information value before cost? 3.3 1.5 4.8 1.8
Question 16What is the number’s status in current performance reporting? Delivered reduction8 kt Funded planned reduction, not operating achievement yet Negative inventory emissions Cash savings necessarily received
Question 17Can a5-week parallel schedule stand? Yes because they are separate branches Yes if the activity colour changes No; require9-week sequencing or a verified extra resource No; always require20 weeks
Question 18What is the funding gap? 0.8 million 0.4 million 1.6 million Zero because support is not capital
Question 19Which procurement requirement best supports verification? Enlarge the environmentally friendly label Treat recyclability as proof of actual recovery Exclude end-of-life from comparison Specify materials, take-back responsibility, cost and recovery-route evidence
Question 20Which measure is closer to a leading indicator of asset operating readiness rather than a lagging outcome? Annual emissions after operation only Successful critical operating-task test before handover Prior-year revenue Project name in a report
Question 21Which statement is correct? Necessarily a95% confidence interval Bounds130 and150 only Conservative range70–210, not automatically95% No uncertainty because savings are positive
Question 22Grid spending10 million within a50-million portfolio: does the grid label alone establish transition alignment? No; require criteria, asset function, dependencies and pathway contribution Yes; every grid asset is automatically aligned Yes; all capital expenditure is abatement No; every grid asset is necessarily fossil
Question 23What is the service gap? No gap because10 exceeds9 2 MW 9 MW 1 MW
Question 24Observation88 is followed by missing data. What should happen? Release because missing equals zero Verify data and do not count missing as below90 Declare equipment failure as certain Replace the missing value with another88
Question 25Standalone efficiency reduces demand15% using the same fuel; a later portfolio is expected to avoid1,300 t. What reduction belongs to the first stage alone? 1,300 t 2,550 t 450 t 1,750 t