Report 4, 03/13/2023
Global Energy Consumption
The third and major source of modern energy is fossil fuels. I present here the history of consumption of different sources of energy, especially in recent decades. I end up with a brief look at the energy costs to produce more energy and how individuals consume energy.
In the first diagram showing energy consumption by source, I indicate my birth date and that of my great-grandfather to illustrate the radical difference in the types of energy that powered the societies of me and those of only 150 years ago. The second diagram illustrates that fossil fuels have provided the energy slaves that have allowed the world’s human populations to grow exponentially.
Until the last half of the 19th century, traditional biomass sources, such as wood and peat, provided most energy other than slaves and very small amounts of energy from renewable sources, such as from wind that powered windmills and sail boats and water that drove waterwheels. With the invention of steam engines, coal became the principal source of energy until the consumption of petroleum surpassed it in the 1960s.
Note that 82 % of the use of all fossil fuels has occurred since 1960 and 50% between 1960 and 2020.
The chart below, shows the changing sources of energy since the year 2000. In terms of total consumption, fossil fuels dominate the energy consumed in the world. In terms of percentage, oil has declined the most, to 33%. Natural gas and renewables have increase the most. Natural gas now produces 24% of the worldâs consumption and renewables, including hydropower, only 10%. The dip in the graph is due to the decline in the economy caused first by the recession of 2008-9 and more recently by the covid pandemic.
The importance of the difference between the sources of total energy consumption and the sources for producing electrical energy are shown in the next diagram. In a future posting, I will further develop the importance of this distinction in the United States.
Energy must be invested to obtain more energy. The energy that is returned on the energy that is invested is often abbreviated as EROEI. All energy is not the same. The energy return on the investment is different for each energy source. The problem, today, is that all newer sources of fossil fuel and biomass and solar yield less energy for the energy invested in producing it than have fossil fuels. The obtaining of newer sources of energy also requires greater investment of money. With high yielding EROEI, fossil fuels of the last few decades grew rapidly. Production has remained high because of demand, but the shift to lower grade energy sources with a lower EROEI portends a decline in consumption as prices rise. Much of the money for maintaining crude oil production with lesser quality of oil has been in the form of loans and subsidies which have yet to be paid back and are not adequately reflected in current price. Recently, when production of crude oil stayed nearly level, prices varied with factors other than with the EROEI and the energy costs of production. Without credit passed on to consumers, the price of oil will increase and the cost of goods will increase. Azenneau, the leading historian of oil, has shown that conventional oil production peaked in 2008. other ways of extracting oil have slightly delayed the actual event of âpeak oil.â
With improved technology, the EROEI of renewable sources is increasing. However, the variables in estimating energy costs vary greatly, especially concerning the costs of energy used in manufacturing, transmission, and storage of new sources of energy. In any case the return in producing usable energy remains very high. I include an older version of EROEI for comparative purposes. I can find no recent graphs that attempt overall comparisons of the major sources of energy.
The diagram, above, indicates that to be economical, a seven per cent return on invested energy is necessary. It indicates that storage costs may limit the EROEI.
The diagram, below, attempts to show the societal needs that can be met at various levels of EROEI based on the use of conventional crude oil. The energy needs of our present society, such as for education, health care, and art need EROI above 8 or 9.
Over 50 years ago, Howard Odum diagrammed ways in which individuals consume energy.
The first diagram, above, shows the energy support of an individual hunter or gatherer. Solar energies (shown in orange) support the wild ecosystem (shown in green), which in turn supports the 2,500 calories to maintain an individual in a tribal group. (shown in pink.) The 2,500 calories in food that supports life in the tribe is lost in heat. (shown in the inverted, dashed triangle.)
The second diagram is of the energy flows that support a modern individual. The renewable energy sources mostly flow through the system and do not directly support the individual. Fossil fuels provide about 250,000 calories to modern society (shown by the vertical rectangle that contains colored, horizontal boxes that represent goods and services.) Goods and services supply energy to the individual (pink hexagon) who, in turn, feeds back some high quality services through his/her work. In the process, the modern individual, like the hunter or gatherer, expends 2,500 calories in metabolism. The difference between the two individuals is 250,000 calories provided by fossil fuels that supports the individual’s share of modern society.
In the next report, I want to delve briefly into the sources, uses, and the history of the consumption of natural materials.