Today, I want to talk about embedded energy, which is hidden in each product that we purchase. Consider a simple hamburger. Its embedded energy includes the energy needed to produce the cattle that made the burger—including the fertilizer that grew its feed and the irrigation system that kept the cow well-watered. It also includes the energy needed to cook both the burger and its bun.
You may not think having lunch is a big source of carbon dioxide emissions to the atmosphere, but embedded energy is in everything we buy.
Consider a new car. To mine the iron ore and make the steel, to mine the silicon sand and make the glass, and to drill for oil, refine it, and make the plastics—all take a lot of energy. The embedded energy used in producing a new car represents about a year of normal gasoline consumption.
When you buy a new car, no matter what sort of mileage it gets, when you drive it off the dealer’s lot, it has already emitted the equivalent of a year’s worth of CO2 from gasoline.
Solar panels are similar. It takes about three years for a solar panel to pay back the energy used to make it. Luckily, solar panels have about a 25-year lifetime, but one does not really begin to help the environment until the end of year three.
When we think minimizing our carbon footprint, many of us think about trimming our reliance on gasoline, electricity, and heating fuel. This is a good step, but properly accounting for our impact on climate requires considering the embedded energy in all of the other products of daily life.
Photo, taken on September 20, 2010, courtesy of JaimeAnne via Flickr.