2. Renewable energy
Renewable energy is energy which comes from natural resources
such as sunlight,wind,rain,tides, and geothermal heat, which
are renewable (naturally replenished). About 16% of global final
energy consumption comes from renewables, with 10% coming
from traditional biomass, which is mainly used for heating, and
3.4% from hidroelecticity. New renewables (small
hydro, modern biomass, wind, solar, geothermal, and biofuels)
account another 2.8% and are growing very rapidly. The share
of renewables in electricity generation is around 19%, with 16%
of global electricity coming from hydroelectricity and 3% from
new renewables.
3. Types of renewable energy:
• Wind power: wind
• Hydropower: water
• Solar energy: the sun
• Biomass: organic material
• Biofuel:solid biomass,liquid fuels and biogases
• Goethermal energy: heat of the Earth
• Wave power: the ocean
4. Wind power
Wind power is the conversion
of wind energy into a useful
form of energy, by using
wind turbines to make
electricity, windmills for
mechanical
power, windpumps for water
pumping or drainage, or
sails to propel ships.
The total amount of
economically extractable
power available from the
wind is considerably more
than present human power
use from all sources
5. Hidropower
Hydroelectricity is the term referring to
electricity generated by hydropower; the
production of electrical power through the
use of the gravitational force of falling or
flowing water. It is the most widely used
form of renewable energy. Once a
hydroelectric complex is constructed, the
project produces no direct waste, and has a
considerably lower output level of the
greenhouse gas carbon dioxide (CO2) than
fossilfuel powered energy plants.
Worldwide, an installed capacity of 1,010
GW supplied hydroelectricity in 2010.
Approximately 16% of the world's
electricity is renewable, with hydroelectricity
accounting for 21% of renewable sources
and 3.4% of total energy sources.
6. Solar energy
Solar energy, radiant light and
heat from the sun, has been
harnessed by humans since ancient
times using a range of ever-
evolving technologies. Solar
radiation, along with secondary
solar-powered resources such as
wind and wave
power, hydroelecticity and
biomass, account for most of the
available renewable energy on
earth. Only a minuscule fraction
of the available solar energy is
used.
7. Biomass
Biomass, as a renewable energy source, is biological
material from living, or recently living organisms .As an
energy source, biomass can either be used directly, or
converted into other energy products such as biofuel.
8. Biofuel
Biofuel is a type of fuel whose energy is
derived from biological carbon fixation.
Biofuels include fuels derived from biomass
conversion, as well as solid
biomass, liquidfuels and various biogases.
Although fossil fuels have their origin in
ancient carbon fixation , they are not
considered biofuels by the generally accepted
definition because they contain carbon that
has been "out" of the carbon cycle for a very
long time. Biofuels are gaining increased
public and scientific attention, driven by
factors such as oil price spikes, the need for
increased energy security, concern over
greenhouse gas emissions from fossil fuels
, and support from government subsidies.
9. Goethermal energy
Geothermal energy is thermal energy
generated and stored in the Earth.
Thermal energy is the energy that
determines the temperature of matter.
Earth's geothermal energy originates
from the original formation of the
planet (20%) and from radioactive
decay of minerals
(80%).Thegeothermal gradient, which
is the difference in temperature between
the core of the planet and its
surface, drives a continuous conduction
of thermal energy in the form of heat
from the core to the surface. The
adjective geothermal originates from
the Greek roots geo, meaning
earth, and thermos, meaning heat.
10. Wave power
Wave power is the transport of energy
by ocean surface waves , and the
capture of that energy to do useful
work— for example,electricity
generation ,water destilation, or the
pumping of water (into reservoirs).
Machinery able to exploit wave power is
generally known as a wave energy
converter (WEC).
Wave power is distinct from the
diurnal flux of tidal power and the
steady gyre of ocean currents. Wave
power generation is not currently a
widely employed commercial technology
although there have been attempts at
using it since at least 1890. In
2008, the first experimental wavefarm
was opened in Portugal, at the
agucadoura wave park.
