Energy consumption accounts for a significant portion of a product's environmental impacts. Biological research suggests the existence of a fundamental energetic limit. After reviewing research into the influence of thermodynamic and economic principles on living systems' evolution, a biological principle explaining the existence of a mass-specific energy consumption rate limit for living systems is identified and quantified. These findings lead to a potential sustainable engineering principle and metric. Simple assessments of consumer goods and vehicles illustrate the principle's application. Discussions of this biologically inspired limit and the general value of seeking environmental design guidance from living systems close this paper.
Keywords: energy consumption, metabolic rate, metabolism, sustainable design, design for environment, DfE, environmental assessment, biomimicry, biologically inspired limit, sustainability, sustainable manufacturing, product design