empty bottles emerging from the bottle factory by the energy bill of the bottle factory, but not surprisingly no one really advertises that fact. The value I used here is a bit of a wild guess, but not off by more than a factor of 10, I’d say. It is a small value compared to the other values.

When I think about the future, it seems that buried in the maker ethos is a fundamental part of the solution.

4. In the case of food, there’s the energy used in its refrigeration and storage.

Photography and digital manipulation by Andrea Dunlap and Dan Benoit

Finally, for the refrigeration of this product I took a shot in the dark. In the real world, this value should be a measure of the number of times it’s cooled, warmed, and recooled, as well as the efficiency of the refrigerators, and the number of days spent on the refrigerator shelf. Again, I used a guess-like value, for illustration.

Those are the easy things to calculate. Harder things to add to the calculation would include the energy to run the computers of the workers in the company that produced the bottle, or the energy for the fluorescent lights in the retailer’s shop.

Harder still are the negative effects of the non-energy, noneconomic factors of the product, like the aesthetic pollution they cause if washed up on beaches, or the health effects of toxic components like the plasticizers. This ethical calculus is very poorly developed, and in my mind one of the most important, difficult, and interesting areas of study in our times. If you’re a student of economics, ethics, or philosophy, this is the frontier.

What comes out of the analysis? Given my confidence in the embodied energy value, I can definitely say that a lower bound for the individual bottle of 5 million joules (MJ) and an upper bound estimate of 8MJ are reasonable.

That’s the energy value; so how did I use this in the calculation of my daily allowance? Humanity currently uses around 15 terawatts (TW) of power. Watts are a rate, that is, an amount of power being consumed all the time: 100 joules consumed each second equals 100 watts.

Undoubtably, 15TW is a lot of power. It’s hard to get an accurate figure, but to level off our CO₂ emissions to prevent global warming, we probably can only afford to make 2TW of that power with carbon-based fuels. The other 13T W would need to come from nuclear power and renewable sources that collectively produce barely 1.5TW right now.

There are 6. 65 billion people on the planet. If you take the bold assumption that they all deserve an equal measure of the Earth’s power resources, that would be 15×1012 / 6. 65× 109 = 2,255 watts each. The average American already uses more than 10,000 watts. I’m going to use 2,000 watts as your

Make: 25