Eric Garza is an energy systems consultant (Aisthetica.com) and a Lecturer at UVM. This is the second in a series of blog posts from Eric on energy use in the food system. Read his previous post here.
In a recent essay entitled The Energy Cost of Food, I estimated that it takes 15-20 Calories worth of energy to deliver a Calorie of food in the United States today, once waste and spoilage are accounted for. Those input Calories are made up of a range of fuels, including gasoline, diesel, electricity, as well as good ol’ elbow grease. Beyond the many fuels that make up the energy cost of food, it’s also useful to differentiate between two broad classes of energy use: direct and indirect.
So what’s the difference? Direct energy use includes fuels used to power vehicles, machinery or built infrastructure, including Calories expended as human labor. Examples of direct energy use include the gasoline that drives food system workers to their job each day, the diesel fuel that powers a farmer’s tractor, and the electricity that keeps a barn’s lights on. Indirect energy includes fuels used to manufacture the vehicles, machinery, appliances, consumable goods, buildings and other infrastructure used within the food system, and to keep a supply of spare parts and other equipment at the ready when repairs are needed. Indirect energy also powers the refineries and mining operations integral to the production of fuels used directly.
So this distinction is really an accounting difference. Why does it matter? Well, food system entrepreneurs keep track of their direct energy use, but indirect energy use often goes unacknowledged. This is unfortunate, since indirect energy can make up the bulk of total energy use in many food system enterprises. Fuels used directly cost money, and energy efficiency programs that target direct energy use can make commercial ventures more profitable and non-commercial ones thriftier. Fuels used indirectly cost money too, though; their dollar value is hidden in the purchase prices of goods and services, and in physical assets like vehicles, machinery and buildings. So when the purchase of large pieces of machinery or built infrastructure is financed by debt, the monetary value of indirect energy must be paid back with interest, inflating its cost further.
So here’s the bottom line: it’s worthwhile, particularly in an era of rising and increasingly volatile energy prices, to be mindful of both direct and indirect energy use. As I do energy audits, particularly those that assess both direct and indirect energy use, on farms and other food sector ventures, the picture I’m getting is that holistic energy management practices depend on holistic assessments of energy use. Managing the ‘embodied’ energy costs associated with equipment and buildings is every bit as important as managing day-to-day purchases of diesel or propane. Vermont leads the way in many things food-related, and it would be wonderful to see entrepreneurs within the state adopt a more holistic approach to energy management that includes mindfulness of both direct energy use and indirect energy use.