When generating
hydropower
Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to produce electricity or to power machines. This is achieved by converting the gravitational potential or kinetic energy of ...
, the head is the distance that a given water source has to fall before the point where power is generated. Ultimately the force responsible for hydropower is
gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
, so a
hydroelectric
Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...
ity plant with a tall/high head can produce more power than a similar plant with a short/low head. In short, for a given water flow, a larger head will be converted into greater
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acce ...
. That energy is then harnessed by a
water wheel
A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or buckets ...
or
water turbine
A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work.
Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now, ...
to create usable hydropower.
Fabrics
Hydrostatic head is also used as a measure of the waterproofing of a fabric, commonly in clothing and equipment used for
outdoor recreation
Outdoor recreation or outdoor activity refers to recreation done outside, most commonly in natural settings. The activities that encompass outdoor recreation vary depending on the physical environment they are being carried out in. These activitie ...
. It is measured as a length (typically millimetres), representing the maximum height of a vertical column of water that could be placed on top of the fabric before water started seeping through the weave. Thus a fabric with a hydrostatic head rating of mm could hold back a column of water five metres high, but no more.
Notes
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See also
*
Hydraulic head
Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22.
It is usually measured as a liquid surface elevation, expressed in units of length, ...
for a more technical description of the physical principle of hydraulics
*
Tent
A tent () is a shelter consisting of sheets of fabric or other material draped over, attached to a frame of poles or a supporting rope. While smaller tents may be free-standing or attached to the ground, large tents are usually anchored using ...
and
waterproofing
Waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environme ...
, as hydrostatic head is used as a measurement of waterproofness
References
U.S. Bureau of Reclamation: Glossary(See “Head”)
(See “Hydraulic head”]
Society of Petrophysicists & Well Log Analysts: Glossary(See “Hydraulic head”)
Hydrology