page_title: Human power
section_title: Human-powered equipment
hierarchical_section_title: Human power / Human-powered equipment
caption_attribution_description: A mechanically powered flashlight. This uses a linear generator and is charged by shaking along its long axis
context_page_description: Human power is work or energy that is produced from the human body. It can also refer to the power of a human. Power comes primarily from muscles, but body heat is also used to do work like warming shelters, food, or other humans.
  World records of power performance by humans are of interest to work planners and work-process engineers. The average level of human power that can be maintained over a certain duration of time⁠ is interesting to engineers designing work operations in industry.
  Human-powered transport includes bicycles, rowing, skiing and many other forms of mobility.
  Human-powered equipment is occasionally used to generate, and sometimes to store, electrical energy for use where no other source of power is available. These include the Gibson girl survival radio, wind-up or radio and pedal radio.
context_section_description: Some equipment uses human power. It may directly use mechanical power from muscles, or a generator may convert energy generated by the body into electrical power.
  Human-powered equipment primarily consists of electrical appliances which can be powered by electricity generated by human muscle power as an alternative to conventional sources of electricity such as disposable primary batteries and the electrical grid. Such devices contain electric generators or an induction system to recharge their batteries. Separate crank-operated generators are now available to recharge battery-powered portable electronic devices such as mobile phones. Others, such as mechanically powered flashlights, have the generator integrated within the device. Wrist watches can use muscle power to keep their mainsprings wound up.
  An alternative to rechargeable batteries for electricity storage is supercapacitors, now being used in some devices such as the mechanically powered flashlight shown here. Devices that store the energy mechanically, rather than electrically, include clockwork radios with a mainspring, which is wound up by a crank and turns a generator to power the radio.
  An early example of regular use of human-powered electrical equipment is in early telephone systems; current to ring the remote bell was provided by a subscriber cranking a handle on the telephone, which turned a small magneto generator. Human-powered devices are useful as emergency equipment, when natural disaster, war, or civil disturbance make regular power supplies unavailable. They have also been seen as economical for use in poor countries, where batteries may be expensive and mains electricity unreliable or unavailable. They are also an environmentally preferable alternative to the use of disposable batteries, which are wasteful source of energy and may introduce heavy metals into the environment. Communication is a common application for the relatively small amount of electric power that can be generated by a human turning a generator.
caption: A mechanically powered flashlight. This uses a linear generator and is charged by shaking along its long axis.
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