The Energy Cost of Local Food

In The Energy Cost of Food I showed how incredibly energy intensive the US food system is. There’s a common assumption among those in the local food movement that one benefit of relocalizing food systems is a reduced demand for energy. As someone who’s been doing energy input-output audits of small farms for years I’ve come to believe that the realities of local food are a bit more nuanced. In The Energetics of Food Distribution I started chipping away at the myth that locally distributed food is always more energy efficient, and in this post I’ll explore the energy cost of local food in greater detail.

The graph below shows, at left, the energy input needed to produce, process and distribute the average calorie of meat, vegetables and dairy according to US Department of Agriculture data [1, 2]. At right are data I’ve gathered on several small farms throughout Vermont. As far as vegetable production goes, the CSA farm uses slightly less energy to get their food to consumers than the average US vegetable supply chain, while the other vegetable farm that sells at farmers’ markets and delivers to some wholesale accounts ends up requiring more than twice as much energy as the US average to put its products in the hands of customers. Realize that ‘Distribution’ in the columns at left are not just the energy used in long-distance transport, but also the energy used in wholesale warehouses and retail outlets which are left out of the local vegetable data on the right. If my audits had included the totality of distribution energy, the columns associated with local producers would be taller still.

On the other side of the fence, I also present data from a local pork & beef farm, a sheep farm, a diversified farm and a grass-based dairy farm. The dairy looks amazing compared to the US average, so amazing that I spent extra time ground-truthing the data to make sure there weren’t errors. It uses less than half as much energy as the average US dairy farm to produce milk, and since it’s grass-based it likely turns out a higher quality product. The audit I did does not include off-farm energy use in processing or distribution though, so my audit doesn’t tell the whole story of this farm’s milk. The sheep and pork/beef operations didn’t fare so well relative to the energy intensity of US meat, on average. Neither of these audits included all food distribution energy or the energy used to slaughter and process meat before sale, so the energy used throughout the entire supply chain for these farms’ meat is higher than what’s shown.

As I point out in The Energy Basis of Food Security there’s a strong relationship between energy prices and food prices owing to the high energy demand associated with food production. As long as local food fails to gain an advantage over larger scale food production in terms of its energy intensity, it’s reasonable to expect the price of local food to trend with energy prices just like food from larger-scale operations. Perhaps the higher energy inputs often needed for small-scale farms partially accounts for why local food tends to be pricier than comparable mass marketed products? While food enterprises in general need to pay more attention to their energy intensity, this is particularly true for smaller enterprises that seek to market their products locally.

Years back a pair of planners, Branden Born and Mark Purcell, wrote an article warning that there’s nothing about smaller scale enterprises that make them inherently better than their larger counterparts [3]. The audit results I’ve presented suggest Born and Purcell’s premise is accurate with respect to the energy intensity of food production. While a few small-scale agricultural operations prove superior to their larger counterparts, most do not. This is true both in the realm of vegetable farms as well as those that raise meat. It doesn’t necessarily have to be this way; I suspect smaller farms have much more flexibility in their management practices than larger operations, so a thorough energy input-output audit could help farmer achieve substantial efficiency gains. The big question, of course, is whether farmers and the communities they serve will see enough value in an energy audit to invest in one.

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