2.3: Current and Future Energy Sources of the World

The World's Energy Supply Sources

Figures 2.3.1 and 2.3.2 show the world's energy supply sources in 2013 and 1973, respectively.

Figure 2.3.1. World's energy consumption in 2013 by fuel source (537 quads)

Data source: International Energy Agency, 2015

Figure 2.3.2. World's energy consumption in 1973 by fuel source (242 quads)

Data source: International Energy Agency, 2015

Figure 2.3.3 shows the projected world energy consumption in 2040.

Figure 2.3.3. Projected world energy consumption in 2040 (815 quads)

Credit: Sarma Pisupati, Data source: Energy Information Administration, International Energy Outlook, 2016

Three of the World's Largest Energy Sources

Currently, the three largest energy sources are oil, natural gas, and coal (all fossil fuels).​​​​​​ Table 2.3.1 provides further information on each source.

Table 2.3.1. Projections and comparisons of the largest energy sources

Source	Future Outlook	Advantages/Disadvantages
Oil	Over the past four decades, oil has been the world's foremost source of primary energy consumption, and it is expected to remain in that position throughout the projected time frame. Liquids (primarily oil and other petroleum products) are expected to continue to provide the largest share of world's energy consumption over the projected period.	In the transportation sector, in particular, liquid fuels continue to provide most of the energy consumed. Although advances in nonliquid-based transportation technologies are anticipated, they are not enough to offset the rising demand for transportation services worldwide. Thus, oil is projected to retain its predominance in the global energy mix and meet 30% of the total primary energy consumption in 2040.
Natural gas	Worldwide natural gas consumption is projected to increase from 120 trillion cubic feet (Tcf) in 2012 to 203 Tcf in 2040. By energy source, natural gas accounts for the largest increase in world primary energy consumption. Abundant natural gas resources from shale resources and robust production contribute to the strong competitive position of natural gas among other resources. Natural gas remains a key fuel in the electric power sector and in the industrial sector.	Natural is seen as the desired option for electric power, given its relative efficiency and environmental advantages in comparison with other fossil energy sources. Natural gas burns more cleanly than either coal or oil, making it a more attractive choice for countries seeking to reduce greenhouse gas emissions.
Coal	Coal is the world’s slowest-growing energy source, rising by an average 0.6% per year, from 153 quadrillion BTUs in 2012 to 180 quadrillion BTUs in 2040. Throughout the projection, the top three coal-consuming countries are China, the United States, and India, which together account for more than 70% of world coal use. Coal use will continue to increase in developing countries, but in developed or industrialized countries, it may slightly decrease.	Global coal production is projected to increase from 9 billion short tons in 2012 to 10 billion short tons in 2040. Most of the projected growth in world coal production occurs in India, China, and Australia. Coal remains a vital fuel for the world's electricity markets and is expected to continue to dominate energy markets in developing parts of Asia.

Electricity

According to International Energy Outlook 2016, the strongest growth in electricity generation is projected to occur among the developing, non-OECD nations. Increases in non-OECD electricity generation average 2.5% per year from 2012 to 2040, as rising living standards increase demand for home appliances and electronic devices, as well as for commercial services, including hospitals, schools, office buildings, and shopping malls. In the OECD nations, where infrastructures are more mature and population growth is relatively slow or declining, electric power generation increases by an average of 1.2% per year from 2012 to 2040.

Figure 2.3.4 shows the energy generation of various sources.

Figure 2.3.4. World net electricity generation by fuel type

Credit: World net electricity generation by fuel type by www.EIA.gov

Nuclear Power

Worldwide, electricity generation from nuclear power is projected to increase from 2.6 trillion kWh in 2015 to 4.5 trillion kWh in 2040.

According to International Energy Outlook 2016 projections by US Department of Energy (US DOE), there is still considerable uncertainty about the future of nuclear power, and a number of issues could slow the development of new nuclear power plants. Issues related to plant safety, radioactive waste disposal, and proliferation of nuclear materials continue to raise public concerns in many countries and may hinder plans for new installations.

Although the long-term implications of the disaster at Japan's Fukushima Daiichi nuclear power plant for world nuclear power development are unknown, Germany, Switzerland, and Italy have already announced plans to phase out or cancel all their existing and future reactors. In contrast, developing Asia is poised for a robust expansion of nuclear generation. Most of the increase is by China's addition of 139 gigawatts (GW) of nuclear capacity from 2012 to 2040.

Fun Fact

In a nuclear plant, heat is produced by nuclear fission (splitting of an atom's nucleus into many new atoms) inside uranium fuel. As a result of fission, heat energy is released and the steam spins a turbine generator to produce electricity.

Hydroelectricity

Moderate growth in the world’s consumption of hydroelectricity and other renewable energy resources is projected over the next 25 years, averaging 1.9% per year. Much of the projected growth in renewable generation is expected to result from the completion of large hydroelectric facilities in developing countries, particularly in developing Asia. China, India, and other developing Asian countries are constructing or planning new, large-scale hydroelectric facilities.

Among the industrialized nations, only Canada has plans to construct any sizable hydroelectric projects over the forecast period. Much of the expected increment in renewable energy consumption in the industrialized world is projected to be non-hydropower renewable energy sources, including particularly wind energy in Western Europe and the U.S. In addition, biomass and geothermal energy sources are expected to grow rapidly in the U.S.

Fun Fact

In hydroelectricity, mechanical energy from the water being pulled downward by gravity is converted to electrical energy. More specifically, a hydroelectric generator directs the flow of water through a turbine, which extracts the kinetic energy from the movement of the water and turns it into electricity through the rotation of electrical generators. Hydropower is the largest single renewable electricity source today, providing 16% of world electricity at competitive prices. It dominates the electricity mix in several countries, developed, emerging, or developing.