Restack: BLTs per Barrel of Oil
We demand complex sandwiches; Self-organizing markets need energy to meet our demand.
This was published a couple of hundred subscribers ago. I get asked about it a lot, so here it is again.
‘It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest.’ — Adam Smith
God gave me a wife. My wife is an endless source of funny mispronunciations and malapropisms. She told me the other day she does not like that new orange “marmanade” I bought: too bitter. I happen to love marmanade.
She somehow fused Marmite (which she HATES) with marmalade, which she also hates. But her heart is in the right place, even though her tongue and hands may not be. Once, during a wedding shower, she rubbed a woman’s rotund tummy and asked when the child was due. The woman explained, hissing through gritted teeth trying to keep cool, that her round belly was caused by a benign tumor that would be removed that very week.
I still laugh about it.
I work in the petroleum industry, so when she asked me how many BLTs were in a barrel of oil I nearly wet my pants. Obviously, she meant BTUs (British Thermal Units), bless her.
After a long laugh, I thought about it. What she asked made sense. More sense actually, to a regular person, than the BTU itself which is the amount of energy needed to heat 1 pound of water 1 degree Fahrenheit.
Why not measure energy by something which is made from that energy? And Bacon, Lettuce & Tomato sandwiches might be the best food for such a measurement. Several industrial supply chains can be analyzed using this delicious, and best, sandwich ever invented. Perhaps several macro-economic phenomena could be understood using the BLT. Fittingly, the British are credited with inventing the BLT. The British also invented the British Thermal Unit… crazy, eh?
The Chart below shows some standard, and BORING, conversion factors. Where are BLTs? Chocolate cake? Thanksgiving Turkey?
Also missing from the chart is a standard, 42-gallon barrel of crude oil which has 5,800,000 Btu, give or take, depending on quality. West Texas Intermediate is a nice one.
So let’s estimate how many BLTs can be made with a barrel of oil using half-assed, un-rigorous methods. I climb the mountain of mediocrity so you don’t have to.
First, we must calculate the cumulative energy needed to raise, grow, fertilize, feed, water, house, transport or chill each BLT component. For the exercise, we shall be BLT purists and not include adjuncts such as turkey, cheese and avocado. We will also not bother with condiments which are used in very small amounts. So: bread, bacon, lettuce and tomato only.
Second, we must also calculate the energy used to toast the bread and fry the bacon. You will have to do all the unit cancellations in your head to check my work (you’re smart or you wouldn’t be reading the Anastomosing Dendrite).
Bread energy required (from a 1980 study): “In the complete production system for standard bread, including wheat growing, flour milling, baking and retailing, primary energy consumption was 14.8 MJ kg-1 bread.”
Dimensions: 1 Btu = 1,055 joules, 1Mj = 1,000,000 joules, 35.3 ounces = 1 kilogram, Standard loaf of bread = 24 ounce and has an average 22 slices.
14.8Mj/kg x 10^6j/1Mk x 1Btu/1055j x 1kg/35.3oz x 24oz/loaf x 1loaf/22 slices = 433.5 Btu of energy are required per slice of bread.
Bacon energy required (from National Hog Farmer): 800 pounds of corn and soybeans are required to grow a hog to maturity. It takes 1,347Btu of energy to grow, dry, harvest and ship 1 pound of soy and 1,235Btu for corn. Hog farms also use propane and electricity: Average 0.41 gallons of propane and 36.7 Kw-hrs electricity per hog. Average mature hog weight is 250 pounds and package weight is 1 pound with 18 slices per pound. I am not including the energy used to process the bacon! Most commercial bacon is now “wet cured” at a very low cost and I could not find those cost data.
Dimensions: 3,412 Btu = 1 Kw-hr, 91,502 Btu in 1 gallon propane, 1,473 Btu to grow and harvest 1 pound of corn and 1347 Btu to grow and harvest 1 pound of soybeans. Assume a 50% corn and soybean mixture.
400lbs corn x 1,235 Btu/1 lb corn + 400lbs soy x 1,347 Btu/1 lb soy + 38.68Kw-hr x 3412/1 Kw-hr + 0.41 gal x 91,502 Btu/gal x 1 hog/250lb x 1 lb/18 slices = 267 Btu of energy is used per slice of bacon.
Tomato energy required: 150 Kilocalories (in the ground) to 560 Kcal (in a heated greenhouse) (IEEE website) for a pithy, flavorless tomato shipped from somewhere nasty. One cannot buy a good tomato anymore. Either grow it or buy from a gardener. I will use larger (560 Kcal) energy tomato which is the only kind available in the non-summer months.
Dimensions: 1 Kilocalorie = 3.97 Btu and 0.33 of a tomato (three thick slices) per sandwich
560Kcal/tomato x 3.97Btu/Kcal x 0.33tomato/tomato slices = 734 Btu of energy is needed for three slices of tomato
Lettuce energy required (from 2017 UC Davis paper): I assume that all costs (less labor and marketing) are related to diesel fuel directly or indirectly: operations, fertilizer, et cetera, and therefore apply the average fuel cost cited in the study ($2.70/gallon) to each carton of lettuce. A head of iceberg lettuce* yields about 8 servings of proper sandwich leaves (the remainder is too watery and small).
Dimensions: $8,296 cost per acre, 900 cartons per acre, 24 heads per carton, 2017 diesel price = $2.70, 137,381 Btu per gallon diesel.
$8,296/acre x 1acre/900 cartons x 1carton/24 heads x 137,381Btu/$2.70 x 1head/8 servings = 2,442 Btu of energy is needed for the sandwich’s lettuce
Total: 2breads(433.5) + 4bacons(267) + 734tomato + 2,442lettuce = 5,111 Btu for all ingredients.
Cooking energy required: the average toaster uses 3.6Kw-hr/month assuming 4 slices per day, the average electric stove uses 11,942Btu/hr and gas stove use 9,000Btu/hr (That’s right, electric stove use MORE energy for the same job!), assume 10 minutes to fry bacon.
TOAST: 3.6Kw-hr/month x 3,412Btu/1Kw-hr x 1 month/30days x 1day/4slices = 102.4 Btu energy used per slice
BACON: 10,471Btu/hr x 1hr/60min x 10min/bacon = 1,745Btu are needed to fry the bacon.
Cooking energy: 2slices(102.4) + 1,745bacon = 1,950Btu are needed to toast and fry
Total BLT energy: 5,111 + 1,950 = 7,061Btu are needed to make one BLT sandwich
BLT per Barrel = 5,800,000 Btu/bbl x 1BLT/7,061Btu = 821 BLTs per barrel of oil.
So there you have it: one barrel of crude oil will grow and cook enough bacon, wheat, tomato and lettuce to make 821 BLT sandwiches. That would feed me for about a week.
You may have noticed that lettuce is expensive while pork is not (excluding the cost of processing bacon). My lettuce estimate is probably wrong, but not by much. Harvesting and transporting lettuce is very expensive and requires each head to be individually packed. Lettuce must be chilled while stored and transported. Consider: the data used in the study is from an “efficient” economy of scale!
ALL the steps required to plant, grow, feed, harvest and ship are tied to a hydrocarbon fuel (gasoline, diesel, natural gas, propane). Every seed must be transported, planted and harvested by a powered machine operated by a guy who rides in another powered machine to work. The wheat, tomatoes and lettuce are fertilized by chemicals made from and generated by petrochemicals or, if fertilized by organics, must still be spread by machines. The economic complexities, the many price discoveries, the myriad dependencies on weather, transport and individual skill just to get these four ingredients to market defy comprehension and prediction. Watch the movie, PI, for an entertaining take on economic complexity and the consequences of “knowing” (see clip below).
Can we make a BLT with only “renewable” energy soon? Unlikely.
Key lesson: GROW YOUR OWN LETTUCE!
Vale!
*I know iceberg is not the preferred BLT lettuce, but these data are probably the same for other types. So get off my back, man!