Reliability, Economics and Responsible Plant Design
Comprehensive university textbook unit covering fundamental principles, governing relationships, and engineering applications of Reliability, Economics and Responsible Plant Design.
§8.1 Failure modes and maintenance planning
**Core topic:** repair time and outage exposure. **Representative relation:** `Availability = MTBF/(MTBF+MTTR)`. **Case context:** unit maintenance register.
§8.2 Capacity credit and reserve planning
**Core topic:** reliability versus output statistics. **Representative relation:** `E_expected = P_rated*CF*8760`. **Case context:** high-demand-week planning scenario.
§8.3 Simple levelized energy cost
**Core topic:** cost per delivered MWh. **Representative relation:** `LCOE = annual_total_cost/E_year`. **Case context:** annualized capital and operation-cost worksheet.
§8.4 Lifecycle impacts and uncertainty
**Core topic:** consistent lifecycle normalization. **Representative relation:** `I_CO2 = m_CO2_lifecycle/E_lifetime`. **Case context:** replacement versus refurbishment comparison.
§8.5 Capstone integrated plant evaluation
**Core topic:** closing energy and decision accounts. **Representative relation:** `Residual_energy = Q_in-P_e-Q_reject-Q_other`. **Case context:** conceptual comparison of three plant options.
Step-by-Step Power Plant Engineering Solutions
Three original questions connect calculations, definitions and interpretation. Open each solution to follow the reasoning.
Problem Statement: In a simplified alternating failure-repair model, MTBF is 5000 h and mean repair time is 100 h. Operational availability is 5000/(5000 + 100) = **98.04%**. Planned maintenance, derated operation and common-cause failures are outside this two-number expression.
Worked Engineering Derivation:
**Verification and limitations.** Annual capacity factor is not the same quantity as availability. The result is illustrative and does not replace equipment-specific property data, measurements or professional review.
Problem Statement: A 100 MW net-rated generator serves peaking demand and has annual capacity factor 25%. Its annual energy is 100 × 0.25 × 8760 = **219,000 MWh**. This output alone says nothing about the value of its availability during the 50 highest-price or highest-stress hours.
Worked Engineering Derivation:
**Verification and limitations.** Capacity credit depends on system need and the probability of resource availability at critical times. The result is illustrative and does not replace equipment-specific property data, measurements or professional review.
Problem Statement: A project reports annualized fixed, fuel and operations cost totaling 40 million dollars and expected delivered annual energy of 800,000 MWh. Its simplified cost is $40,000,000/800,000 = **$50/MWh**. The figure is not a complete financed project LCOE unless the capital annualization, taxes, financing and other assumptions have been specified.
Worked Engineering Derivation:
**Verification and limitations.** A cheaper mean $/MWh may still fail to supply capacity, flexibility or the required environmental service. The result is illustrative and does not replace equipment-specific property data, measurements or professional review.
Problem Statement: A lifecycle inventory attributes 400,000 tonnes of CO2-equivalent to a project, and lifetime net energy delivery is 5,000,000 MWh. The intensity is 400,000/5,000,000 = **0.08 t CO2e/MWh**, or 80 kg/MWh. Changes to the boundary—construction, fuel supply, or end-of-life—change the result.
Worked Engineering Derivation:
**Verification and limitations.** Uncertainty and allocation choices should be visible rather than hidden in one exact-looking number. The result is illustrative and does not replace equipment-specific property data, measurements or professional review.
Problem Statement: A conceptual plant receives 400 MW(th), exports 155 MW(e), rejects 210 MW(th) through cooling, and has 25 MW(th) of other quantified losses. The unclosed energy residual is 400 − 155 − 210 − 25 = **10 MW(th)**. The analyst must investigate this residual as possible unmeasured loss, stored-energy change, or measurement error; it must not silently disappear.
Worked Engineering Derivation:
**Verification and limitations.** A closed spreadsheet is not sufficient evidence of plant safety, emissions compliance or economic viability. The result is illustrative and does not replace equipment-specific property data, measurements or professional review.