Transcript ALTERNATIVE SOURCES OF ENERGY

ALTERNATIVE SOURCES OF
ENERGY
By Cesare Rollo and Alessandro Manieri
What ASOE are?
•
ASOE (Alternative sources of energy) are sourses based on renewable energy. It involves natural
phenomena such as sunlight, wind, tides, plan growth, and geothermal heat. They could power
the world without using raw materials up and polluting water, atmosphere and soil.
What are the most common kind of
ASOE?
• There are a lot of different kinds of ASOE, but some of them are the
most widespread . That’s due to economical and pratical reasons, in
fact some of them are much easier to exploit and don’t need huge
investiments or are very profitable (usually with the economical aids
of the countries).
They are :
Solar Energy
• Nevertheless its production is very changable (day/night,
summer/winter), it can be used everywhere in the world and It can
be exploited in different ways:
• With photovoltaic cells or with solar towers to produce eletricity;
• With boilers to produce hot water.
The first way is the most spread because of the very low cost and the
chance to use it for little needs. New materials such as CIGS alloy
(copper, gallium, indium and selenium) make this sistem very
productive so more profitable. Usually photovoltaic sytems are
installed together with solar systems for hot water, in order to reduce
the power dependence.
The second one instead is quite rare, because it needs big
investiments and installations even thought it produces a higher
amount of electrical energy.
Wind Energy
• Though wind energy is now affordable, easly available, and
pollution-free, it does have some drawbacks. The fact that it is a
"very diffuse source" means that a large number of wind generators
(so large land areas) is required to produce useful amounts of heat
or electricity. But wind turbines can’t be erected everywhere simply
because many places are not windy enough. When an appropriate
place is found, building and maintaining a wind farm can be
expensive.
• Anyway in good condition it can be much more profitable than solar
energy so much more attractive for investitors.
Hidropower
• Energy in water can be used quite easly. Since water is about 800
times denser than air, even a slow flowing stream of water, can
produce considerable amounts of energy. Hydroelectric energy is a
term usually reserved for large-scale hydroelectric installations.
Micro hydro systems are hydroelectric power installations, which
typically produce up to 100 kW of power, aren’t as unusal as it can
seems to be, and they of course don’t need a dam. These systems
are very productive but of course they are limited to little fluvial
areas.
Geothermal
• Geothermal energy is thermal energy generated and stored in the
Earth. Earth's geothermal energy originates from the original
formation of the planet (20%) and from radioactive decay of minerals
(80%).
This energy can be used to produce electrical energy with big
installations. The high cost of these systems and the lack of suitable
places makes this sourse rare. Anyway in the few places where it
can be exploited it may be very productive.
Emerging renewable energy
technologies
•
•
•
•
•
There are a lot of new kinds of techonologies in the energy field.
Some of them seem to be very interesting and could become really important.
For example Tidal Power is the generation of electrical power through the harnessing of the ebb
and flow of the tides. A barrage, which is in fact a huge dam, is built across a river estuary or bay.
This barrage has gates in it which allow the water to flow into the barrage with the incoming tide.
These gates are then closed when the tide begins to go back out. There are other gates within the
barrage which are now opened; these gates contain hydro-electric generators, very similar to the
ones used in Hydropower. The main downfall of tidal power generation is the capital needed at the
beginning of the project to construct the barrages.
Some scientists substain they can use cold nuclear fusion reactions to produce energy. This
could be a great innovation but probably it will take years to become reality.
Biomass (plant material) is a renewable energy source because the energy it contains comes
from the sun. Through the process of photosynthesis, plants capture the sun's energy. When the
plants are burnt, they release the sun's energy they contain. In this way, biomass functions as a
sort of natural battery for storing solar energy. As long as biomass is produced sustainably, with
only as much used as is grown, the battery will last indefinitely.
In general there are two main approaches to using plants for energy production: growing plants
specifically for energy use (known as first and third-generation biomass), and using the residues
(known as second-generation biomass) from plants that are used for other things. See biobased
economy. The best approaches vary from region to region according to climate, soils and
geography.