Humankind consumes vast amounts of energy each year. Some energy sources can be used directly—for instance, coal and natural gas can be burned to heat homes. But more often, energy sources are used to produce electricity, which has an almost boundless range of uses. These include heating and cooling homes; preparing food; and powering a vast array of modern devices, from cell phones and computers to satellites and medical equipment.
In order to determine overall energy consumption, it is necessary to combine consumption data for many energy sources, including (but not limited to): electricity consumption by country, oil consumption by country, natural gas consumption by country, and coal consumption by country.
In terms of overall energy consumption, the United States and China dwarf all other countries, with China using the most electricity and the U.S. consuming the most oil. Although many factors contribute to a given country's energy consumption—level of industrial development, geographical size, standard of living—the single most influential factor is population. This point is supported by the facts that China, the U.S., and third-place India are the world's three most populous countries, and also rank high in meat consumption per country (but not, perhaps surprisingly, in milk consumption.
As shown in the tables above, when broken down by energy category, the order changes but the countries included stay largely the same. However, when consumption totals are divided by the population to determine the per capita use of energy, the highest consumer is neither the United States, China, nor any other country in the top 10. Instead, that honor goes to Iceland.
In 2019, Iceland ranked 73rd in the world in electricity consumption and tied for 139th in oil consumption (see data table after body text). But the country's average energy use per capita in 2020 was more than 167,000 kilowatt hours per person per year. For comparison, China had the highest overall energy consumption in the world, but also the highest population, resulting in a comparatively minuscule average energy use of 28,072 kWh per person per year.
There also exist nations that consume very little energy. This is typically due to the countries having a small overall population, but factors like the level of development (particularly infrastructure such as roads and electrical grids) also play a role. Whatever the reason, more than two dozen countries and territories consume fewer than a billion kilowatt hours of electricity per year, and eleven are known to consume very little oil as well.
|British Virgin Islands||Falkland Islands||Montserrat||Sao Tome and Principe|
|Dominica||Micronesia||Saint Pierre and Miquelon|
While mankind's ability to convert Earth's natural resources into energy has improved nearly every aspect of modern life, energy use also has a detrimental aspect. For example, the generation and delivery of electricity requires the construction of large and expensive infrastructure, including millions of miles of wires and cables. Electricity increases the risk of fire in the home, particularly is installed unprofessionally or used to power aging or worn-out appliances. Furthermore, electrical power plants (particularly coal-fired plants) generate significant pollution, which degrades air quality and contributes to global warming.
Oil presents a similar trade-off. Even before the invention of the internal combustion engine revolutionized transportation of both humans and product, oil was used to provide light and heat to homes and businesses—but it must be burned in order to unleash its energy, and as such releases significant greenhouse gases and contributes heavily to both the carbon footprint per country and global warming.
These concerns have led to rising interest in green and renewable energy sources, with many countries increasing their investment in wind power, solar power, and other forms of renewable energy, with the coal of ultimately becoming a carbon negative country.
China uses the most amount of energy based on its total billion kWh usage, but the United States is responsible for using the most oil in the world.