Can we Power the World by Trimming Fat?
Most recent answer: 11/11/2012
Q:
I thought to solve the problems we have with obesity and supplying the world with its energy needs, we could use the excess fat our bodies don't use to power electrical appliances. Is anyone doing research on this and if it can't be done why not?
- Tom (age 32)
UK
- Tom (age 32)
UK
A:
That's an interesting thought. Let's do a quick rough calculation.
Say that you could trim off about a pound a month. That's about 15 gm/day. I think some of that is just water, so let's round down to 10 gm/day. Burning a gram of fat releases about 4 kcal of energy. So we have about 40 kcal/day or about 160 kJ per day. Real electrical generators are rarely better than about 40% efficient at converting chemical energy to electrical energy, so let's say that gives 60 kJ of electrical energy. With about 105seconds/day, that would only be about 0.6 W on the average. In real life you'd need a huge amount of resources, including energy, just to do the surgery. It's a losing scheme.
It does suggest something useful, however. By walking and biking instead of driving, you get exercise, lose some of that same weight, and reduce consumption of fossil fuels for transportation. That's a winner.
Mike W.
Say that you could trim off about a pound a month. That's about 15 gm/day. I think some of that is just water, so let's round down to 10 gm/day. Burning a gram of fat releases about 4 kcal of energy. So we have about 40 kcal/day or about 160 kJ per day. Real electrical generators are rarely better than about 40% efficient at converting chemical energy to electrical energy, so let's say that gives 60 kJ of electrical energy. With about 105seconds/day, that would only be about 0.6 W on the average. In real life you'd need a huge amount of resources, including energy, just to do the surgery. It's a losing scheme.
It does suggest something useful, however. By walking and biking instead of driving, you get exercise, lose some of that same weight, and reduce consumption of fossil fuels for transportation. That's a winner.
Mike W.
(published on 11/11/2012)