A SYSTEMATIC REVIEW OF ENERGY EXERGY AND ECONOMIC ASSESSMENTS OF BREWERY ENERGY SOURCING PATTERNS

Abstract

Breweries combine low- and medium-temperature process heat with refrigeration, electricity, compressed air, water treatment and batch scheduling, so energy-source decisions must be evaluated jointly. This systematic review synthesised 33 brewery-specific studies using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement, the PRISMA extension for searches (PRISMA-S) and Synthesis Without Meta-analysis (SWiM) guidance. Searches of Scopus, Web of Science, ScienceDirect and Google Scholar covered records through 25 July 2026. The evidence comprised 19 audit, process-integration and exergy studies and 14 renewable, electrification, waste-to-energy and digital-control studies. Steam generation, brewhouse heating, wort boiling, refrigeration and packaging were the recurrent hotspots. Reported case-study results included 21.5% heat-recovery potential, overall exergy efficiency as low as 3.33%, and a dual-source heat-pump case with 60% lower modelled carbon emissions and 10% lower energy cost. Results were heterogeneous because boundaries, brewery scale, production schedules, tariffs, discount rates and validation methods differed. The proposed efficiency-first hierarchy requires breweries to meter utilities, correct avoidable losses and recover heat before sizing heat pumps, renewable supply or waste-to-energy systems for residual demand. This sequence reduces retrofit capacity and financial exposure. Practitioners should require transparent boundaries, life-cycle cash-flow assumptions and sensitivity analysis, while policymakers should prioritise metering standards, audit support and performance-linked incentives. Figure 1 summarises the evidence pathway and decision sequence.