Energy Efficiency of Thermal Power Generation in Ecuador's Sacha Oil Field

This study reassesses the relative energy efficiency of the thermal generation system serving Ecuador's Sacha Oil Field during 2020-2023. A quantitative, retrospective, nonexperimental longitudinal case-study design examined a census of 49,185 daily unit records from 11 plants; standardized operational spreadsheets and a structured extraction matrix were the data-collection instruments. The objective was to establish the system baseline and identify defensible operational conclusions. An input-oriented constant-returns-to-scale data envelopment analysis model used daily diesel, natural gas, and bunker consumption as inputs and daily electricity generation as output. The validated unbalanced panel contained 49,185 day-by-unit observations from generating units grouped within 11 plants. Conventional annual mean efficiency was 0.880, 0.910, 0.891, and 0.869, while bias-corrected means were 0.869, 0.903, 0.883, and 0.855. Medians exceeded means in every year, indicating a lower-performing tail rather than uniform underperformance. However, the observed decline in frontier membership during 2023 cannot be attributed entirely to technical deterioration because the panel expanded from 43 to 56 units and the empirical frontier changed. The study therefore interprets the index as an internal, sample-dependent benchmark, not absolute thermodynamic efficiency or proof of attainable savings. The corrected article identifies plant-level priorities, explains the limits of interannual comparison, and proposes engineering validation before operational targets are assigned.