Building on prior discussions at ACEEE Summer Studies and elsewhere, we argue that today's primary focus on energy efficiency may not be sufficient to slow (and ultimately reverse) the growth in total energy consumption and carbon emissions. Instead, policy makers need to return to an earlier emphasis on "conservation," with energy efficiency seen as a means rather than an end in itself. We briefly review the concept of "intensive" vs "extensive" variables (i.e., energy efficiency vs energy consumption), and why attention to both consumption and efficiency is essential for effective policy in a carbon- and oil-constrained world with increasingly brittle energy markets. To start, energy indicators and policy evaluation metrics need to reflect energy consumption as well as efficiency.
We introduce the concept of "variable" (consumption-sensitive) efficiency, 1 where the level of efficiency varies as a function of size (for a home), capacity (for an appliance), or scale of energy consumption. We propose introducing variable efficiency criteria first in consumer information programs (appliance test methods, categories for appliance labeling) and then in voluntary rating and recognition programs (LEED and ENERGY STAR for homes). As acceptance grows, the concept could be extended to utility rebates, tax incentives, and ultimately to mandatory codes and standards.
For these and other programs, incorporating both consumption and efficiency criteria offers a path for energy experts, policy-makers, and the public to join debate and build consensus on energy policies that recognize finite resources and global carrying-capacity, perhaps helping to shift our shared expectations from perpetual growth toward sufficiency and sustainability.