6.2 - Global Energy Consumption

Learning Objectives

I. Developed Versus Developing Nations

• Per capita use (developed nations): The average citizen in a developed country uses far more energy than the average person in a developing country. Developed countries consume more energy on a per person basis.
• The United States uses almost four times as much energy per person as the world average: about 75,000 kWh per person in 2025, compared with about 20,000 kWh for the world (Energy Institute data, via Our World in Data). The average person in India used about 7,400 kWh, roughly one tenth as much as the average American.

• Total use (developing nations): Because there are so many more people in the developing world, those countries use a higher share of the world’s total energy.
• Example: China uses more total energy than any other country, more than a quarter of the world's total, even though the average person in China uses less than half as much energy as the average American.

• Growing demand in the developing world: Total energy use there is rising because of two big factors:
1. Population is still growing.
2. Economies are still industrializing and advancing in manufacturing and consumption of goods, which raises standards of living and per capita consumption.

II. Dominance of Fossil Fuels

A. Main Uses of Fossil Fuels

• Oil / petroleum: Mainly used in transportation as a fuel source (gasoline) for cars.

• Coal: Still the largest single source of electricity in the world, about 33% of global electricity in 2025, down from around 40% in the early 2010s. In 2025, renewables as a group (33.8%) made more electricity than coal (33.0%) for the first time (Ember, Global Electricity Review 2026).

• Natural gas: The second biggest source of electricity worldwide (about 22% in 2025), and it hasn't passed coal globally. In the U.S., natural gas passed coal in 2016 and is now the top source of electricity. It is also the main heating fuel, burned in home furnaces and other buildings.

B. Secondary Energy Sources

• Hydroelectricity: The largest non-fossil source of electricity, about 14% of world electricity in 2025, though far behind fossil fuels. Energy comes from water, typically a dam creating a reservoir whose water rushes through a turbine.

• Nuclear power: About 9% of world electricity in 2025. It generates electricity through the fission of uranium, which heats water into steam to spin a turbine.

• Solar and wind: The fastest-growing sources. In 2025, solar passed wind for the first time and nearly matched nuclear, and wind and solar together made about 17% of the world's electricity (Ember).

III. Increasing Development and Fuel Shift

• Subsistence fuels: Underdeveloped and developing countries often rely on subsistence fuels, meaning fuels that can be easily gathered and burned at home for heat or cooking, like wood, dried animal manure, charcoal, or any easily collected biomass. They are used because they are cheap and readily available, and they avoid utility costs.

• The transition: As economies develop and wealth increases, residents start demanding and using more energy.
• There is a positive correlation: as GDP rises, per capita electricity and energy demand rises.
• As demand grows, people can no longer rely on subsistence fuels. They shift to fossil fuels, using oil for transportation and natural gas and coal for electricity and heating.
• Real example: Energy use per person in China more than tripled from 2000 to 2025, and in India it more than doubled. Most of that new energy came from fossil fuels, and coal still supplies more than half of China's energy.

IV. Factors Affecting Energy Source Use

1. Availability: Fossil fuel use depends heavily on availability, specifically the size of discovered reserves and how accessible those reserves are.
• When availability increases, for instance when new reserves open up (like U.S. shale gas, opened up by fracking starting in the late 2000s), the price drops substantially.
• That lower price causes use of the fuel to shoot way up. Natural gas use increased while coal use began to decline.

2. Price: People and power companies usually pick the cheapest option that does the job.
• Cheap fracked natural gas made gas power plants cheaper to run than coal plants, a big reason U.S. coal use fell.
• Solar and wind got much cheaper: the average cost of electricity from new large solar farms fell about 90% between 2010 and 2024 (IRENA), so they are now among the cheapest new power sources in many countries.
• When gasoline prices spike, people tend to drive less, carpool, or switch to more fuel-efficient cars.

3. Government regulation: Governments can significantly shape energy use by mandating specific energy mix requirements, for example requiring 25% of energy to come from renewables.
• How governments affect prices: In the U.S., governments mostly change energy prices indirectly, through taxes (like the federal gasoline tax of 18.4 cents a gallon) and subsidies. Some prices are set more directly: state utility commissions approve the rates many electric companies charge, and some oil-producing countries subsidize gasoline so it sells far below world prices.
• Incentives: Governments can raise taxes on fossil fuel power plants to discourage building them, or offer tax credits and rebates to encourage companies to build renewable plants.
• Regulation often reflects the political sentiment and willingness of a country to push green energy.
• Renewable portfolio standards (RPS): The name for these energy mix requirements. Many U.S. states have one; California's requires 60% of its electricity to come from renewables by 2030 and 100% from carbon-free sources by 2045.

V. Practice Calculation: Energy Use Per Person

• Exam tip: Write the units on every number and show them canceling. FRQ points usually go to the setup, not just the final answer.