Tuesday, March 18, 2008

Is energy expensive?

With the price of oil surging well past US$100, Michael Tobis reminds us that energy is actually quite cheap:

A hundred dollars a barrel. A barrel! Energy is unbelievably cheap.

That's about six million BTUs. One point seven megawatt hours. With that $100 barrel you can power your laptop for two years. You can ship hundreds of pounds of bananas from Guatemala. You can microwave a hundred and two thousand cups of tea to steaming warmth. You can power the digital clock on your microwave for seven million years!

Tobis and commenter John Mashey relate oil prices to the debate over buying local food.

So how much does it cost to carry a tomato from California to Maine?

It's about 3000 miles. It's about 1/4000 of a ton. So its about 3/4 of a ton mile. OK, make it a nice big juicy tomato. It's a ton-mile. So that costs about 1/200 of a gallon of fuel, or about a penny and a half.

Suppose the price of fuel quadruples. Your tomato will cost almost an extra nickel. Big deal.

The bottom line of many life cycle analyses is that buying local is not always the most efficient choice. One must weigh the energy required to produce the local food with the energy required to produce and ship the "global" food (including the indirect costs of maintaining the shipping network).

1 comment:

TimC said...

Glad to see someone bringing this up. I certainly think that we have to reduce CO2 emissions starting four decades ago, but when you think about it, the reason why we ship produce is because it is generally cheaper to produce elsewhere or on an industrial scale even when one includes the cost of transportation. And whereever there are additional costs in growing the produce locally, you have to ask: where are those costs coming from -- and do they have a carbon footprint?

Subsidize alternate energy? I can certainly see that. Try to reduce energy and water consumption, use more efficient lightbulbs, or increase required fuel efficiency? Certainly.

But going only to local growers? Think twice. (Of course, there is the problem with monocultures and the fact that they will put our food supply at additional risk particularly in the context of rapid climate change, but that is another matter -- and could be addressed by other means.)