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Sustainability Matters 11: More about Energy Consumption


More about Energy Consumption

Each country seems to have its own pattern of energy consumption.

The US historically has used the most energy in relation to income. Japan’s energy use, though less than the US, has been rising steadily, while the UK’s energy use has remained relatively static. China and India are in similar places to where the US and UK were in the 1800’s, which suggests they have a long road of development ahead of them. They also represent the largest potential source of worldwide energy demand we are likely to see over the next half century.

Figure 3-18:  Primary energy use (GJ) versus GDP (at market exchange rates (MER) in 2005US$) per capita. Source: USA, Japan: updated from Grubler, 1998, UK: Fouquet, 2008, India and China: IEA (2010) and World Bank (2010). Note: Data are for the United States (1800–2008), United Kingdom (primary and final energy, 1800–2008), Japan (1922–2008), China (1950–2008), and India (1950– 2008). For China and India, also GDP at purchasing power parities (PPP, in 2005 International$) are shown.

The graph above also suggests the potential of energy efficiency. Japan and the UK have similar standards of living to that of the United States, but seem to do it with about half the amount of energy. This has to do with variety of factors including geography and cultural norms.  

As you can see, the question, “How much energy do we use?” has no simple answer.

The world requires upwards of 330 EJ of final energy (see Figure 3-13) to do the work provided by 169 EJ of useful energy. Given the relationship between energy consumption and development, it is safe to assume that the availability of affordable energy is one of the prerequisites for economic development. If less developed countries are to grow, it is clear they will demand more energy. Whether they take the same or different growth paths as the more developed nations will be influenced by technology, communications and how a society integrates cultural norms and economic conditions.  

Now let’s turn to the future. How much energy will the world demand in the future? 

The most recent projections published by the US Energy Information Administration predict that renewable energy and nuclear power will be the fastest growing sources of energy between 2013 and 2040, each growing on average by 2.5% yearly. 

They also predict that natural gas will be the fastest growing fossil fuel.

Figure 3-19: International Energy Outlook.  Source: U.S. Energy Information Administration, 

According to the EIA’s publication, Today in Energy, the world used 524 quads of energy (553 EJ) in 2013 and is projected to use 820 quads (865 EJ) in 2040, an increase of 56% in primary energy demand.  The projected continued dominance of fossil fuels to meet this increase would see 45 billion metric tons of CO2 emitted in 2040, a 46% increase over 2010 levels.

According to the same report, the industrial sector will continue to use a large percentage of the final energy. Much of that industrial growth will come with the economic development of Asia, which is expected to show the greatest increase in demand for energy between now and 2040. This is consistent with the previous year’s IEA report, “Future world energy demand driven by trends in developing countries,” which published the following graph. 

Figure 3-20:  Projected World Primary Energy Consumption 

In OECD countries energy consumption is expected to grow at a rate similar to the population, 

Non-OECD countries – highly concentrated populations with fast growing and developing economies with fast changing habits – will drive significant increases in energy use. 

Energy use in non-OECD countries is projected to grow by 2.2% per year, and the share of non-OECD energy use is expected to rise from 54% of total world energy use in 2010 to 65% in 2040.

What about Energy Usage in the United States?

In 1950, the US population reached 152 million, and its total primary energy consumption was 34.6 quads. By 2009, US population increased to 307 million, and its total primary energy consumption grew to 94.9 quads. Energy consumption increased to 95.1 quads by 2012.

Two sectors of the economy accounted for 90% of this increase. Electric generation increased from 4.7 to 38.5 quads between 1950-2009, while the transportation sector rose from 8.4 to 27.2 quads during the same period. The following charts describe the energy consumption and demand flow by sector in the US. For each source, we can follow the path through the sectors for which the energy is being used. We can also see the breakdown of fuel sources for each demand sector. The following are two different ways of analyzing the data. Figure 3-21 is a representation of 2008 data and 3-22 a representation of data from 2009.

Figure 3-21: US Dept. of Energy, “U.S. Primary Energy Consumption by Source and Sector, 2008” (2009)

Figure 3-22:  Primary Energy flow to Final Energy

The above charts represent snapshots of energy use for single years (2008 and 2009), while the following chart shows the evolution of these sectors over the course of the last 40 years (1970-2016). You can see the trend, as discussed above, of increased consumption for transportation and electric generation within the residential and commercial sectors. 

Figure 3-23: Energy Consumption by Sector (1970 – 2016)

The following is a chart of US energy usage for 2012. We consumed 95.1 quads of primary energy, which yielded 53.9 quads of final energy, which ultimately yielded 37 quads of useful energy. That works out to a 38% efficiency from primary to useful energy, slightly higher than the world average of 33%.

Figure 3-24

The boxes on the left represent primary energy, and the pink boxes represent final energy. The dark grey represents useful energy services. Secondary energy is harder to calculate from these numbers, but its flow is represented by the “spaghetti” between primary and final energy.

This chart also suggests areas of potentially large energy efficiency savings. The light grey areas represent rejected heat lost through inefficient conversions. This chart suggests that the two places where we lose the most energy are electricity generation and transportation. 

The following graph of projected US primary energy consumption for 2010-2050 is based on a series of different scenarios run by the Rocky Mountain Institute.  

Figure 3-25: Energy Consumption in the U.S. Economy, 2010-2050

The top green wedge shows us the potential for assertive energy efficiency policy action in limiting future energy consumption. The line between the top green wedge and the blue wedge represents the ‘business-as-usual’ scenario based on 2010 trends. Without efficiency measures put in place through 2010, the top of the green wedge would be the business-as-usual line. 

The chart shows US demand for energy rising to just over 100 quads yearly by 2050 if no additional efficiency measures are implemented. As we will see in the next chapter, there is some question as to how long this growth pattern can be sustained.

The area between the top of the yellow area and the bottom of the green area represents what the Rocky Mountain Institute sees as potential for efficiency, which could drop consumption by a third by the end of the century. 

We now have a clearer understanding of how much energy we use and the complexity of the energy systems we depend upon to provide us with that energy. To review, world primary energy consumption was just under 500 EJ year in 2005. That turned into 330 EJ of final energy and 169 EJ of useful energy. Of that the US demanded about 91 EJ of primary energy and consumed 35 EJ of useful energy. These numbers have continued to climb over the past decade. 

Recent Energy Consumption Estimates

World Primary and Useful Energy Consumption Historical Estimates
2013 World Primary Energy Consumption 553 EJ Grubler
2015  World Primary Energy Consumption 571 EJ American Geosciences Institute
2016 World Primary Energy Consumption 565 EJ BP
2013 World Useful Energy Consumption 169 EJ Grubler
United States Primary and Useful Energy Consumption Historical Estimates
2012 US Primary Energy Consumption 90.57 EJ Grubler
2016  US Primary Energy Consumption 102 EJ IEA
2012 US Useful Energy Consumption 37 EJ Grubler
Projected Primary and Useful Energy Consumption Projections
2040 World Primary Energy Consumption  865 EJ Grubler
2040 World Primary Energy Consumption  777 EJ EIA


How much energy we choose to consume is, to a point, up to us. There are, however, physical limits to how much energy we can consume.

We will explore some of those limits in the next post.



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