Growing concern over the world's ever-increasing energy
needs and the prospect of rapidly dwindling reserves of oil, natural gas,
and uranium fuel have prompted efforts to develop viable alternative energy
sources. The volatility and uncertainty of the petroleum fuel supply were
dramatically brought to the fore during the energy crisis of the 1970s
caused by the abrupt curtailment of oil shipments from the Middle East
to many of the highly industrialized nations of the world. It also has
been recognized that the heavy reliance on fossil fuels has had an adverse
impact on the environment. Gasoline engines and steam-turbine power plants
that burn coal or natural gas emit substantial amounts of sulfur dioxide
and nitrogen oxides into the atmosphere. When these gases combine with
atmospheric water vapour, they form sulfuric acid and nitric acids, giving
rise to highly acidic precipitation. The combustion of fossil fuels also
releases carbon dioxide. The amount of this gas in the atmosphere has steadily
risen since the mid-1800s largely as a result of the growing consumption
of coal, oil, and natural gas. More and more scientists believe that the
atmospheric buildup of carbon dioxide (along with that of other industrial
gases such as methane and chlorofluorocarbons) may induce a greenhouse
effect, raising the surface temperature of the Earth by increasing the
amount of heat trapped in the lower atmosphere. This condition could bring
about climatic changes with serious repercussions for natural and agricultural
The solution, then, seems simple: Humans have to kick the fossil-fuel
habit. Put more scientifically, they must “de-carbonize the energy economy,”
says Seth Dunn of Worldwatch Institute. To some extent this has been happening
for quite some time as carbon-intensive firewood yielded to coal and then
to oil as the world’s primary energy source. Today natural gas, by far
the cleanest of the fossil fuels, is gaining ground and is projected to
account for 26 percent of world supply by 2020.
The brightest hope for the future lies in a commitment to increase
energy efficiency, reduce demand, and move toward use of renewables—power
drawn from wind, sun, water, geothermal heat, and even so-called biomass
such as forest and farm waste. The world has seen some heartening progress
already. In China, an aggressive energy-efficiency program has helped cut
the use of coal by some 400 million tons per year, “an extraordinary success
story,” says Michael Totten of Conservation International. And wind is
on the rise. Clean and endlessly renewable, wind is the fastest growing
energy source in the world.
Many countries have initiated programs to develop renewable energy
technologies that would enable them to reduce fossil-fuel consumption and
its attendant problems. Fusion devices are believed to be the best long-term
option, since their primary energy source would be the hydrogen isotope
deuterium abundantly present in ordinary water. Other technologies that
are being actively pursued are those designed to make wider and more efficient
use of the energy in sunlight, wind, moving water, and terrestrial heat
(i.e., geothermal energy). The amount of energy in such renewable and virtually
pollution-free sources is large in relation to world energy needs, yet
at the present time only a small portion of it can be converted to electric
power at reasonable cost. *
A variety of devices and systems have been created to better tap
the energy in sunlight.
Solar Energy, radiant energy produced in the sun as a result of nuclear
fusion reactions. It is transmitted to the earth through space in quanta
of energy called photons, which interact with the earth's atmosphere and
surface. The energy from the sunlight has been ultilised for centuries
now in different ways. The fact that plants are able to ultilise this energy
in the process of photosynthesis means that we ultilise the sun's energy
in our day to day activities either directly, in production of Vitamind
D or indirectly, the food we eat and the fuel we use. Scientists have seeked
for away to ultilise solar energy directly so that it can serve as an alternative
to fossil fuels. Efforts have been put world wide and different projets
are developed each day to meet this objective. To day Solar energy is widely
used in Britain to warm houses. Inventions such as the solar pannels and
photovoltaic cells are able to capture solar energy and to convert this
energy to electrical energy.
Geothermal reservoirs with temperatures of 180° C or higher
are suitable for power generation.
Geothermal energy is plentiful, but geothermal power is not. Temperatures
increase below the Earth's surface at a rate of about 30° C per kilometre
in the first 10 kilometres. This internal heat of the Earth is an immense
store of energy.
The earths mantle is made up of hot molten lava. This causes the earths
core to be a source of underground steam and hot water reservoir. This
trapped heat was brought to practical use in 1904 in Italy. It was seen
that this heat could be used to move turbines which then generate electricity.
In geothermal power station this heat is brought into the surface trhough
drill holes.Holes drilled into a subsurface geothermal system allow rapid
mass transfer of hot water or steam to the surface. Hot water from lower
temperature geothermal reservoirs can be used for space heating. This form
of geothermal power is utilized extensively in Iceland.
Some geothermal systems act as natural distilleries in the subsurface,
dissolving trace amounts of gold, silver, and other rare elements from
their host rocks. These elements may then be deposited at places where
changes in temperature, pressure, or composition favour precipitation.
Geothermal energy is widely ultilised in the United States of America,
some countries such as Japan and some European countrie.
Converting the energy in moving water to electricity has been a
Hydro power, power derived from the fall of water from a higher to
a lower level, and extracted by means of waterwheels or hydraulic turbines.
Waterpower is a natural resource, available wherever a sufficient volume
of steady water flow exists. Hydro electric power is extensively used in
many countrie world wide. Cana is probably the largest producer of hydro
electric power in the world. Although hydro electric power is a good alternative
to fossil fuels and economical in many countries, it is nott economical
where call is cheap.
Since hydro electric power infrastructures require the building of
dams, it has been found to disturb ecological balance. Some fish species
have faced endangerement and the latest is the frog incident of Tanzania.
Where a large number of rare frog species that can give birth were discovered
to face endangerement due to insufficient water. This is so because all
the water is trapped in the dam.
Hydroelectric power plants are estimated to provide only about 2 percent
of the world's energy requirements.
Sailing ships, pumping water, drying clothes, the list of tasks
we ask of wind expands in size with our expanding imagination.
Current concerns over energy, specifically electricity supply, brings
wind power to the fore front of energy planning, Although wind is intermittent
and diffuse, it contains tremendous amounts of energy. Sophisticated wind
turbines have been developed to convert this energy to electric power.
The utilization of wind energy systems grew discernibly during the 1980s.
For example, more than 15,000 wind turbines are now in operation in Hawaii
and California at specially selected sites. Their combined power rating
of 1,500 megawatts is roughly equal to that of a conventional steam-turbine
Ultilisation of wind energy however is a cumbersome technology, and
conservationalists and environmentalists are concerned with the land that
has to begiven up to install the giant fans.
Although could cause devastating effects its probably the best solution
to boost energy for the world.
Is the energy stored in the nucleus of an atom and released through
fission, fusion, or radioactivity. In these processes a small amount of
mass is converted to energy according to the relationship E = mc2, where
E is energy, m is mass, and c is the speed of light. The most pressing
problems concerning nuclear energy are the possibility of an accident at
a nuclear reactor or fuel plant, such as those which occurred at Three
Mile Island (1979), Chernobyl (1986), and Takaimura, Japan (1999), and
the potential threat to the continued existence of the human race posed
by nuclear weapons. *
Nuclear energy from the day of its discovery has found a great utility
in the mordern technological world. It has been widely applied in
medical fields in treating cancers and tumors. Although the misuse of nuclear
energy results to devastating situations and everlasting negative impacts
on humans such as the hiroshima disaster. It is probably the best alternative
for the worlds growing energy demands. Currently only few countries are
capable of producing nuclear energy due to its complex technology and expensivity.
The fact that the living things store energy have brought about the
thought for the ultilisation of this energy. Bio gass is widely use in
India and other parts of the world. The feaces of animals or plant materials
are kept in a large tank with a little water and the tank is sealed. This
allows a culture of bacteria to develope, these bacteria produce methane
gass on decomposing the material in the tank. Methane beign inflammable
can be used as LPG substitute. Cowdung can be directly ultilised if dried.
Ethanol and biodisel are examples of biofuels, widely used in the U.S.A.