As Howard Odum noted in his classic work on environmental accounting, “The natural conversion of sunlight to electric charge that occurs in all green-plant photosynthesis after 1 billion years of natural selection may already be the highest net emergy possible.”
Emergy—embodied energy—is nearly invisible to us. In a previous post I looked at how emergy might help us better understand the energy that the Internet uses. But beyond such analyses, I’ve started to see the world through the lens of embodied energy and/or net energy. It’s been a slow and strange transition for me; I’ve begun to see every object around me not only for its function but for its manufacture. Obviously it takes time and mental effort to not just go about our days interacting with things around us but instead thinking about them. But it’s that blindness to emergy that contributes to poor energy decision-making.
There are a number of examples of this from everyday life: instances in which considering emergy would help us easily make the energy-efficient choice. Consider food. We know that there are numerous reasons to grow food on our own or to buy from local farms, yet the easiest way to think about it is to consider the emergy of the food from different sources. Emergy calculations also help us choose between, for example, food that was grown with the use of pesticides and food that was grown without it (even though, once again, there are reasons to avoid pesticides). Consider buying new vs. used goods. The amortized emergy of a used item is nearly always less than the emergy cost of a new item.
Neither of these examples is novel: buying used and buying local are well known notions. However, emergy analysis provides an all-purpose tool for decision-making in these and other instances. It may not always solve the problem—particularly when doing the emergy analysis itself is difficult—but I think it may help in most cases.
As a result of thinking about embodied and net energy, I’ve found myself asking a lot of strange questions, many of which may not even be well-formed. (I’ve also wondered if it might help to broaden these concepts to embodied resources and net resource expenditure rather than narrowly considering energy alone.) I’d like to list some of them here, and try to find answers to them in some future post:
- Are tropical fruits sweeter because they have more energy from the sun at their disposal?
- Are ebooks really more efficient than paper books, as is sometimes claimed? Are printed handouts (e.g. conference proceedings) more efficient than flash drives? Are libraries more efficient than ebook stores (and their corresponding devices)?
- Do blended raw-food diets make people feel energetic because they have greater net energy?
- What makes food sustainable? Is “sustainable fish” sustainable?
- Are human-powered tools actually more energy-efficient than electrical tools or equivalent machines?
- How much energy did it take to produce the Windows operating system? What about the Mac OS? Is it more efficient to download an OS update or get it in the mail?
- What style of farming / gardening has the highest net energy (e.g. industrial vs. industrial-organic vs. small raised bed-organic vs. organic permaculture vs. biointensive-organic vs. etc.)?
- What natural systems / phenomena would yield the highest emergy and/or available net energy (e.g. lightning vs. oil vs. volcanoes vs. high-altitude wind vs. ocean thermal gradients vs. etc.)?
- What is the emergy of a flywheel bicycle? Is it more efficient to use a flywheel bicycle than a regular bicycle?
- In general, do buffers in systems increase their net energy?