HYDROPOWER

Hydropower also known as water power, is the use of falling or fast-running water to
produce electricity or to power machines. Since ancient times, hydropower
from watermills has been used as a renewable energy source for irrigation and the
operation of mechanical devices, such as gristmills, sawmills, textile mills, trip hammers,
dock cranes, domestic lifts, and ore mills. A trompe, which produces compressed air from
falling water, is sometimes used to power other machinery at a distance.
Hydropower is an attractive alternative to fossil fuels as it does not directly produce
atmospheric pollutants. However, economic, sociological, and environmental downsides limit
its use. International institutions such as the World Bank view hydropower as a low-carbon
means for economic development.
Hydroelectricity is the biggest hydropower application. Hydroelectricity generates about 15%
of global electricity and provides at least 50% of the total electricity supply for more than 35
countries.
The size of hydroelectric plants can vary from small plants called micro hydro; to large
plants supply that power to a whole country. As of 2019, the five largest power stations in
the world are conventional hydroelectric power stations with dams.
Hydroelectricity can also be used to store energy in the form of potential energy between
two reservoirs at different heights with pumped-storage. Water is pumped uphill into
reservoirs during periods of low demand to be released for generation when demand is high
or system generation is low.

TYPES-
Hydroelectric power plants vary in terms of the way they harvest energy. One type involves a dam and
a reservoir. The water in the reservoir is available on demand to be used to generate
electricity by passing through channels that connect the dam to the reservoir. The water
spins a turbine, which is connected to the generator that produces electricity.
The other type is called a run-of-river plant. In this case, a barrage is built to control the flow
of water, absent a reservoir. The run-of river power plant needs continuous water flow and
therefore has less ability to provide power on demand. The kinetic energy of flowing water is
the main source of energy.
Both designs have limitations. For example, dam construction can result in discomfort to
nearby residents. The dam and reservoirs occupy a relatively large amount of space that
may be opposed by nearby communities. Moreover, reservoirs can potentially have major
environmental consequences such as harming downstream habitats. On the other hand, the
limitation of the run-of-river project is the decreased efficiency of electricity generation
because the process depends on the speed of the seasonal river flow. This means that the
rainy season increases electricity generation compared to the dry season.
ENERGY TRANSFORMATION-
Hydropower plants capture the energy of falling water to generate electricity. A turbine
converts the kinetic energy of falling water into mechanical energy. Then a generator
converts the mechanical energy from the turbine into electrical energy.

RELIABILITY-
As long as flowing water is available, hydropower plants of any size can reliably generate
electricity. Hydropower is physically reliable because it is more efficient than many other
energy sources and can run consistently with little maintenance, making it an ideal source of
base load power.

ADVANTAGES OF HYDROPOWER-
 Hydropower is fuelled by water, so it's a clean fuel source, meaning it won't
pollute the air like power plants that burn fossil fuels, such as coal or
natural gas.
 Hydroelectric power is a domestic source of energy, allowing each state to
produce their own energy without being reliant on international fuel
sources.
 The energy generated through hydropower relies on the water cycle, which
is driven by the sun, making it a renewable power source, making it a more
reliable and affordable source than fossil fuels that are rapidly being
depleted.
 Impoundment hydropower creates reservoirs that offer a variety of
recreational opportunities, notably fishing, swimming, and boating. Most
water power installations are required to provide some public access to the
reservoir to allow the public to take advantage of these opportunities.
 Some hydropower facilities can quickly go from zero power to maximum
output. Because hydropower plants can generate power to the grid
immediately, they provide essential back-up power during major electricity
outages or disruptions.
 In addition to a sustainable fuel source, hydropower efforts produce a
number of benefits, such as flood control, irrigation, and water supply.

DISADVANTAGES-
Dams and reservoirs can have major negative impacts on river ecosystems. Large and deep
dam and reservoir plants cover large areas of land which causes greenhouse gas emissions
from underwater rotting vegetation. Furthermore, although at lower levels than
other renewable energy sources, it was found that hydropower produces methane gas which
is a greenhouse gas. This occurs when organic matters accumulate at the bottom of
the reservoir because of the deoxygenation of water which triggers anaerobic
digestion. Furthermore, studies found that the construction of dams and reservoirs can result
in habitat loss for some aquatic species