Manure Recoverability Governs the Available Biogas Resource and Emissions: Peruvian Livestock as a Case Study

National estimates of the bioenergy potential of livestock manure still rest on static inventories that apply conversion yields to the gross mass of manure, ignoring the fraction that is actually recoverable under each production system and the substrate-specific nature of anaerobic co-digestion. This study develops a category-level predictive model of the technical biogas potential of livestock manure in Peru, projected to 2030, resolving seven livestock categories: dairy and non-dairy cattle, broilers and layers, swine, guinea pigs (Cavia porcellus) and goats. Recoverability is formulated as a time-dependent factor tracking the progressive confinement of production systems; the technical potential is bounded between a mono-digestion floor and a co-digestion ceiling constrained by a co-location criterion that admits synergy only when the co-substrate originates within the same production system; and a greenhouse-gas layer quantifies avoided emissions from methane conversion factors. All coefficients are reported as intervals and propagated jointly by Monte Carlo simulation. Two yield hypotheses are carried throughout: experimental biochemical methane potential and the IPCC-consistent digester ceiling. The national net technical potential is 1975 GWhpyr−1 under mono-digestion (731 GWhe; 95% credible interval 1628–2404 GWhp, Monte Carlo N=100,000) and 2093 GWhpyr−1 under co-digestion. The gross approach exceeds the recoverable resource by a factor of 3.94, equivalently a contraction of 74.6% (95% CI 68.9–79.1%), and a symmetric Shapley decomposition attributes 76.1% of that contraction to recoverability rather than to conversion yield—a share that is stable across both yield hypotheses. The greenhouse-gas layer yields a result that reverses the expected policy ordering: broilers rank first by recoverable energy but last by avoided methane, whereas swine rank first by mitigation because liquid slurry storage is the only baseline system emitting enough methane for anaerobic digestion to displace. Below a digester leakage of 4.6%, methane abatement is negative at the national scale.