The Energy Underpinning our Modern World
Summary: Our modern economies present us with a smorgasbord of products and experiences, mostly underpinned by processes burning fossil sunlight. We tend to take the energy embedded in it all for granted. The USA uses 98 “quads” of primary energy each year. Quad stands for a quadrillion BTUs and equates to about 172 million barrels of oil. The USA uses 38 of these 98 quads as inputs to generate electricity, which, at an average thermal efficiency of 33%, result in 12.8 quads of useful electricity. But on a net bas is, only 21% of America’s energy use is electricity. 183 The majority of our energy use comes from natural gas, distillate and propane for heat, diesel, motor and aviation fuel for transport, and a vast array of various hydrocarbon compounds for machine lubricants, asphalt to build roads, and other industrial processes such as making steel, wire, glass and cement.
When considering a future powered by “renewable energy,” using sources that primarily generate electricity, some key points need be considered:
• Concrete, a very energy-and CO 2 -intensive product, is the
foundation for most of our buildings, infrastructure and highways. Humans are now producing over three billion tons of cement (the main ingredient in concrete) each year, with over half of that being created in China. (In fact, from 2011-2013, China created more cement than the United States has in its entire history. 184 ) Cement, steel and other industrial products require extremely high heat.
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