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Energy and Resources Factfile |
 Energy and Resources |
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Renewable Energy
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| As fossil fuels have started to run out, so countries are beginning to use
sources of renewable energy. Renewable energy is sometimes called alternative
energy. This is because it provides people with an alternative to fossil fuels
and other non-renewable energy sources. People are concerned about future
energy demands and whether there will be enough natural resources to meet
demand.
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Solar, wind, hydro-electric and geothermal energies are based on alternative
energy sources and this energy will be around for as long as the Earth is, so
we don’t have to worry about running out of it.
Solar energy
Solar energy is energy obtained from the Sun’s radiation. Solar heating is
widely used for industrial or domestic purposes and is a major non-polluting
and renewable energy source.
Advantages – solar panels use sunlight to produce electricity, solar
power is a clean source of energy and relatively cheap to produce.
Disadvantages – solar power cannot be generated at night or on cloudy
days, so homes also have to have a conventional backup system that uses fossil
fuels.
Wind power
For centuries, the wind has been used to sail ships and pump water. Now people
use the wind to generate electricity. Wind turbines usually have 2 or 3 blades
that turn as the wind blows and in turn the blades drive a generator that
produces electricity, much like steam turbines. The longer the blades and the
faster the wind speed, the more electricity the turbine generates.
Large groups of wind turbines, called wind farms, are connected to electric
utility power lines and provide electricity to many people.
Advantages – wind power is a very clean source of energy; no waste or
pollution is produced, electricity can be produced whenever the wind blows (at
night and also during the day).
Disadvantages – lots of turbines are needed to produce a useful amount
of energy, many people think wind turbines are unattractive and noisy.
Hydro-electric energy
The water in rivers and streams can be captured and turned into hydropower,
also called hydro-electric power. Hydro-electric power plants in the USA
generate enough electricity to power whole towns, cities, and even entire
regions of the country.
Advantages – Hydro-electric power can produce a large amount of energy
and is cheap to produce. It also does not produce air pollution.
Disadvantages – Damming rivers for hydropower can change the ecology of
the region.
Geothermal energy
We can also get the energy directly from the heat in the earth. This is known
as geothermal energy and it starts with hot, molten rock (called magma) miles
below the earth’s surface that heat a section of the earth’s crust. The heat
rising from the magma warms underground pools of water known as geothermal
reservoirs. If there is an opening through the rock to the surface, the hot
underground water may seep out to form hot springs, or it may boil to form
geysers.
Advantages – there are many potential sites for geothermal energy and
many sites are in LECDs.
Disadvantages – we could run out of geothermal energy by drawing so much
energy out of the reservoir that it is not able to replenish itself at the rate
we’re using it, water from geothermal reservoirs often contains minerals that
are corrosive and polluting.
Oil power plant - Iraq
While demand for energy is increasing both in the UK and at a global level,
there are important differences in patterns of energy demand across the world:
80% of the world’s population lives in a less economically developed country
(LEDC) – yet LEDC’s only use 20% of the world’s energy. But development by
LEDCs means they want more resources.
20% of the world’s population lives in a more economically developed country
(MEDC) – yet MEDCs consume 80% of the world’s energy. Some MEDCs fear any
attempt to get them to reduce their consumption of fossil fuels could badly
affect the country’s economic growth and so they have begun to import natural
resources from LEDCs as their own supplies have started to run out.
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