US Energy Use
Energy use in the US is dominated by fossil fuels—oil (or more formally, petroleum), gas (or more formally, natural gas), and coal (which is generally just called coal). Recently, fossil fuels have been totaling about 85% of energy sales in the US (and more-or-less 85% worldwide), with the rest of US use split more-or-less equally between nuclear and renewables. (In 2010, the US Energy Information Administration gave US energy supply as Oil 37%; Gas 26%; Coal 21%; Nuclear 8%; Renewables 8%. This was used to move us around (transportation 28%), to build things (industrial use 20%), to heat and cool houses (residential 11%) and to power our plugged-in gizmos (electricity 40%).
Video: U.S. Energy Supply (0:52)
Credit: Dutton Institute. "EARTH 104 Module 2 Energy Use." YouTube. October 6, 2012.
Source: The figure is modified by Richard Alley from Figure 1.3, US Energy Information Administration, Annual Energy Review 2010
We’ll revisit these issues later. US usage per person is a little smaller than some countries, but (much) larger than many others. Per person, the world averages roughly 1/4 of US use. Most of the world's economy is dominantly fossil-fueled with people often getting about 85% of their energy from fossil fuels as in the US, and energy is often about 10% of the economy.
Activate Your Learning
In the previous section, we learned that the average person in the US uses ~10,000 watts of energy while producing only 100 watts from the food they eat. If average world energy use is about 1/4 of that in the US, and assuming all people produce about the same amount of energy from the food they eat, do people worldwide create as much energy from eating food as they use in their daily lives?
Click for answer.
For now, though, it should be evident that if we spend 10% of our money on energy, it impacts everything—jobs and security and environment and more. As we saw in last week's Discussion, there are great options for making money and saving money by doing things better in the energy business. But, over the last few decades, we actually have doubled the amount of economic activity squeezed out of each barrel of oil or ton of coal—bright people have been working on this, and making or saving much more money might take a lot of effort or some new inventions.
Perhaps most importantly, the current system is grossly unsustainable. As we will see in upcoming content, the store of fossil fuels in the Earth is limited, and we are removing them much more rapidly than nature makes new ones. With essentially everything we do relying on energy use and 85% of the energy system relying on unsustainable fossil fuels, a lot of things will need to change.
Earth: The Operators' Manual
Video: China: In with the New - A 4-minute clip on China's movement toward alternative energy use.
Credit: Earth: The Operators' Manual. "China: "In with the New"." YouTube. April 9, 2012.