In the human context, energy refers to the physical and mental energy required to perform various tasks, including physical activity, work, and mental effort. Energy is essential for human survival and well-being, and plays a critical role in maintaining physical and mental health.
Physical energy refers to the energy required for physical activity, such as exercise, manual labor, and sports. Physical energy is generated by the body's metabolic processes, which convert food and oxygen into energy. Physical activity and exercise can help maintain physical energy levels, while a lack of physical activity can lead to decreased energy levels and decreased physical and mental well-being.
Mental energy refers to the energy required for mental effort, such as focus, concentration, and problem solving. Mental energy can be influenced by factors such as sleep, nutrition, stress, and mental stimulation. Mental activity, such as reading, learning, and creative pursuits, can help maintain mental energy levels, while a lack of mental stimulation can lead to decreased mental energy and well-being.
In addition to physical and mental energy, energy also refers to the energy required for daily living, such as performing household tasks, caring for others, and commuting. This energy can be impacted by factors such as stress, time constraints, and environmental factors, and can have significant impacts on overall well-being and quality of life.
Overall, energy is an important aspect of human life, and understanding and managing energy levels can help improve physical and mental health, as well as overall well-being and quality of life.
How do humans exploit energy?
Humans use a variety of methods to exploit energy, including:
Fossil fuels: This is the most widely used method of energy exploitation, which includes coal, oil, and natural gas. These fuels are formed from ancient organic matter and are extracted from the earth by drilling or mining. They are then burned to generate heat and electricity.
Nuclear energy: Nuclear energy is generated by splitting atoms in a process called nuclear fission. This generates heat, which is used to produce steam to generate electricity.
Hydroelectric energy: Hydroelectric energy is generated by harnessing the kinetic energy of falling water to turn turbines, which generates electricity.
Solar energy: Solar energy is harnessed through the use of solar panels, which convert the sun's energy into electricity.
Wind energy: Wind energy is harnessed through the use of wind turbines, which convert the kinetic energy of wind into electricity.
Geothermal energy: Geothermal energy is harnessed by tapping into the heat of the Earth's interior, which can be used to generate electricity or to heat buildings.
Biomass energy: Biomass energy is generated by burning organic materials, such as wood, crops, and waste, to generate heat and electricity.
Tidal and wave energy: Tidal and wave energy are harnessed by using turbines or other devices that convert the kinetic energy of tides and waves into electricity.
Fuel cells: Fuel cells are devices that convert chemical energy into electricity. They can be powered by hydrogen, natural gas, or other fuels.
Human powered energy: Human powered energy is generated through the use of devices such as bicycles, treadmills and other equipment that convert the kinetic energy of human movement into electricity.
All of these methods have their own advantages and disadvantages, and are used in different ways and settings depending on the cost, efficiency, safety, environmental impact and other factors.
How much energy do Humans use?
Humans use a significant amount of energy. According to the International Energy Agency (IEA), global energy consumption has been increasing steadily in recent years, and in 2019, the total global energy consumption was about 167,078 TeraWatt-hours (TWh) per year.
The majority of this energy consumption comes from non-renewable sources such as fossil fuels, which accounted for around 85% of global energy consumption in 2019. The remaining 15% comes from renewable energy sources, such as hydroelectric, wind, solar, geothermal, and biomass.
Energy consumption per person varies greatly depending on factors such as location, income, and lifestyle. According to the World Bank, in 2018, the average global energy consumption per capita was around 3,527 kilowatt-hours (kWh) per year. However, energy consumption per capita is much higher in developed countries than in developing countries, for example in 2018, the energy consumption per capita in the United States was about 13,246 kWh/person/year, while in India it was about 833 kWh/person/year.
It's worth noting that energy consumption per capita does not take into account population growth, so the total energy consumption is expected to increase in the future. Additionally, the energy consumption of human society has a big impact on the environment and climate change, which is a concern that needs to be addressed by transitioning to more sustainable energy sources and reducing energy consumption in general.
| Bibliographic Entry | Result (w/surrounding text) | Standardized Result |
|---|---|---|
| Life: The Science of Biology. Ed. William K. Purves and David Sadava. 7th ed. New York: Freeman, 2004: 962. | "The basal metabolic rate of a human is about 1,300-1,500 kcal/day for an adult female and 1,600-1,800 kcal/day for an adult male." | 5.44 - 6.28 MJ (female) 6.69 - 7.53 MJ (male) |
| "Human Nutrition and Diet: Recommended Intakes of Nutrients." The New Encyclopedia Britannica. 15th ed. Vol. 13. 1983: 422. | "The energy expended for maintenance at rest, known as the basal metabolism, amounts to about 1.25 kilocalories per minute for a man weighing 65 kilograms (one pound = 2.2 kilograms) and 0.90 kilocalorie per minute for a woman weighing 55 kilograms." | 5.42 MJ (female) 7.53 MJ (male) |
| Heini, A. F. Divergent Trends in Obesity and Fat Intake Patterns: the American Paradox. American Journal of Medicine. 102 (1997): 259-264. | "Average total daily calorie intake also tended to decrease, from 1,854 kcal to 1,785 kcal (−4%)." | 7.47 MJ |
| Stigliani, William M., and Thomas G. Spiro. Environmental Issues in Chemical Perspective. Albany, NY: SUNY Press, 1980: 6. | "Table 1.1 shows some of the quantities that have been discussed. It also shows that the total energy consumed by the burning of fossil fuels amounted to 6.0 × 1019 calories in 1975. This is about one-twelfth of the net primary productivity. The energy content of the food consumed by human beings in the same year was only 3.2 × 1018 calories. This is 2.2 million calories per person per day, which is close to the minimum estimated to be required for the daily energy needs of humans." | 9.20 MJ |
| Heslin, Jo-Ann, and Annette B. Natow. "Understanding Calories." Introduction. The Calorie Counter. 4th ed. New York: Simon & Schuster, 2007: 5. | "On average, we eat 300 more calories a day than we ate 35 years ago and we weigh 24 pounds more. Women eat 1880 calories a day; men eat 2620." | 7.87 MJ (female) 11.0 MJ (male) |
Input - Process - Output
We should optimise our energy use to support our physical bodies and a sustainable life.