Electric Humans

Tradition tells us that Thanksgiving commemorates a feast involving the Pilgrims, as well as the Native Americans who contributed to this feast in the early 1600s.[1] Accordingly, our modern Thanksgiving holiday is often marked by time off from work or school and a lot of eating. Eating gives us energy we need to stay alive, and by coincidence, time off is said to “recharge our batteries.” Of course that’s just a coloquial expression about recharging our batteries. Admittedly, we probably do recharge actual batteries during our time off, considering the various portable devices we use – cell phones, laptops, flashlights, electric razors, GPSes, and many more. It certainly would be convenient if we could recharge ourselves by plugging into a power source. Assuming that could even work, which is currently doubtful, how much would it cost to recharge a human with electricity?

It’s actually not hard to calculate the cost of electricity for powering a human for one day. Let’s assume we need the stereotypical daily allowance of 2000 food calories. We just need to somehow convert that 2000 calories to electricity and then determine the cost of that electricity. A food calorie is a unit of energy from food, just like a kilowatt-hour (kW*h) is a unit of electrical energy. A food calorie is also known as a kilocalorie, indicating it is 1000 of the calories typically used in physics and chemistry.[2] A kilocalorie is about 0.001162 kW*h. And the price of one kilowatt-hour? As of 11/02/2020, the price of electricity in the United States had a range from $0.0941/kW*h to $0.2887/kW*h, according to the Choose Energy web site.[3] The average price was $0.1331/kW*H, according to the same source.

Putting it all together, that original 2000 food calories is 2000 kilocalories. Those kilocalories are actually 2.324 kW*H, which cost a whopping $0.31. Yes, the energy for one day would cost us less than 50 cents per day if it were electricity. How can it be so much cheaper than what we normally pay for food? The subject of food is not so simple, to put it mildly. We like our food to taste good, not contain impurites, not be spoiled, and not be the same all the time. For the most part, electricity is electricity, assuming the voltage and AC frequency remain constant.

For comparison, suppose we could survive by consuming only all-purpose flour and water. In 2018, all-purpose flour is said to have cost an average of $2.50 for a 5-pound bag, leading to a cost of $0.50 per pound in that year.[4] White all-purpose flour has 364 kilocalories per 100g, with there being 453.59g in one pound.[5][6] That comes to about 1651 kilocalories per pound. That’s about 80% of where we need to be, so maybe the full 2000 kilocalories for one day could have cost us about $0.63 in 2018, on average. Considering everything done to that flour – planted, farmed, harvested, ground, bleached somehow, packaged, shipped, and shelved – the price really is not that bad. It also provides some of the necessary materials for our growth and repair, not just energy. But to be able to plug into the electric grid or even a windmill or solar panel to get more energy? The price for that convenience can’t be beat either.

References

[1] https://www.history.com/topics/thanksgiving/history-of-thanksgiving

[2] https://en.wikipedia.org/wiki/Calorie

[3] https://www.chooseenergy.com/electricity-rates-by-state/

[4] https://www.howmuchisit.org/how-much-does-flour-cost/

[5] https://www.recipal.com/ingredients/6335-nutrition-facts-calories-protein-carbs-fat-wheat-flour-white-all-purpose-unenriched?user_id=1

[6] https://www.metric-conversions.org/weight/pounds-to-grams.ht m