The importance of considering energy security and resource efficiency in policies across the Department of Defense (DoD) has recently been emphasized. DoD-sponsored research reports repeatedly encourage consideration of energy efficiency and energy security in all decision-making processes, including those that pertain to Forward Operating Military Base Camp (FOB) equipment. But while energy security and efficiency are valued in the general sense, for FOBs, energy and water are strategically vital and sources of vulnerability. There are incredibly high human and capital costs associated with transporting fuel and water within hostile war zones, where convoys are routinely subjected to mortal danger. A volumetric framework for evaluating field equipment is proposed that simultaneously addresses the broad DoD-wide goals of bolstering energy security and energy efficiency, as well as the immediate and strategically significant goal of "taking [fuel and water delivery] trucks off the road." The metrics associated with this framework focus on the volume of field equipment itself, as well as the volumes of fuel and water that are either consumed or saved by the equipment over time. For example, solar panels require additional up-front volume to be brought to the FOB, but then spare future volumes of fuel that need not be shipped. Using a volumetric framework described herein, the tradeoffs between up-front and marginal volumetric requirements can be rigorously assessed. Existing metrics, such as those that focus only on equipment lifecycle cost, are unsuitable for evaluating field equipment for FOBs primarily because they are extremely difficult to accurately quantify. By instead focusing on fuel and water volumes that are more easily quantified, decision-makers might gain important insights about the relevant trade-offs and strategic implications of fielding equipment on FOBs. The proposed metrics are compared to existing metrics with respect to their effectiveness for quantifying the true values of energy- and water-saving devices on FOBs in a strategically relevant way. A suite of volume-based metrics is developed by adapting existing economic metrics, including return on investment (ROT), payback period, and net present value (NPV), for a volume-based rather than cost-based analysis. Use of the volumetric framework is illustrated for a few different technologies.
