Energy requirements
Almost everything a person does in their day-to-day life requires energyThe capacity of a system to do work or the quantity required for mechanical work to take place. Measured in joules (J). For example, a man transfers 100 J of energy when moving a wheelbarrow.. Much of the energy that is used by people comes from a range of different stores. Systems that can store large amounts of energy are called energy sources.
Energy sources are physical things, but energy is not. The major energy sources available for use are fossil fuelNatural, finite fuel formed from the remains of living organisms, eg oil, coal and natural gas. (coal, gas and oil), nuclear power, biofuelA type of energy source derived from renewable plant and animal materials, eg ethanol (often made from corn in the United States and sugarcane in Brazil), biodiesel (vegetable oils and liquid animal fats) and biogas (methane from animal manure)., wind power, hydroelectricityElectricity that is generated by the movement of water. , tidal powerEnergy generated from the movement of tides., and solar power.
Within communities, energy is used in a range of different ways:
- in homes, energy is needed for cooking, to run appliances, and to keep a house warm
- in places such as schools and hospitals, energy needs include running machinery and warming rooms
- in factories and farms, heavy duty machines and production chains are run by the energy supplied to them by the National Grid
- transport systems, such as buses, trains, cars and boats use fuel or electricity to run
Learn more on energy transfers in everyday appliances in this podcast
Listen to the full series on ±«Óătv Sounds.
Patterns and trends in how energy sources are used
Hundreds of years ago, human beings used wood as their main source of energy for fire, as this was readily available. Today, the energy needs of the human race are very different to what they used to be, due to the modernisation of technology and machinery. This means that the way energy is harnessed has also changed.
Over the last century, fossil fuels have been the main source of energy in most developed countriesCountries where people have a high standard of living.. However, because of the recognised impact on the environment of burning fossil fuels, this method of generating energy is slowly reducing. Scientists and governments are working to develop the use of renewableEnergy sources that are replenished and not exhausted, eg solar power. energy sources, such as wind power, solar power, and hydroelectricity. Much work has also been done over recent decades to make machines, technology, and people's own homes more efficientPerforming in the best possible manner with little time, money or energy wasted..
The demand for energy also varies with the time of year and the time of day. For example, during early evenings there is a lot of demand for heating, lighting and cooking. This demand falls overnight while people sleep. During winter, more heating and lighting is required than in summertime.