3. Wind Energy
●
The high speed winds have a lot of energy in them as kinetic energy due to their
motion. The wind energy is harnessed by making use of wind mills. The blades of
the wind mill keep on rotating continuously due to the force of the striking wind.
The rotational motion of the blades drives a number of machines like water
pumps, flour mills and electric generators. A large number of wind mills are
installed in clusters called wind farms, which feed power to the utility grid and
produce a large amount of electricity.
●
These farms are ideally located in coastal regions, open grasslands or hilly
regions, particularly mountain passes and ridges where the winds are strong and
steady.
●
The minimum wind speed required for satisfactory working of a wind generator is
15 km/hr.
●
The wind power potential of our country is estimated to be about 20,000MW,
while at present we are generating about 1020MW. The largest wind farm of our
country is near Kanyakumari in Tamil Nadu generating 380 MW electricity.
5. Wind Energy
●
Advantages
– High net energy yield
– Renewable and free
– Very clean source of energy
●
No pollution (air or water) during operation
– Long operating life
– Low operating/maintenance costs
– Can be quickly built; not too expensive
– Now almost competitive with hydro and fossil fuels
– Land can be used for other purposes
●
Can combine wind and agricultural farms
6.
7. Hydroelectricity
●
Currently largest source of electricity from renewables.
●
Needs guaranteed supply of water.
●
The hydropower potential of India is estimated to be about
4 × 10 11KW-hours.
●
Kinetic energy of water rotates turbines which generate
electricity.
8. Hydro Energy
●
Advantages
– Cheap to operate
●
Long life and lower operating costs than all other power plants
– Renewable
– High yield
●
Lower energy cost than any other method
– Pretty plentiful
●
Some countries depend almost entirely on it
– Not intermittent (if reservoir is large enough)
– Reservoirs have multiple uses
●
Flood control, drinking water, aquaculture, recreation
– Less air pollution than fossil fuel combustion
9.
10. Geothermal Energy
●
How it works
– Geothermal power plants
●
Use earth’s heat to power steam turbines
– Geothermal direct use
●
Use hot springs (etc) as heat source
– Geothermal heat pumps
●
Advantages
– Renewable
– Easy to exploit in some cases
– CO2 production less than with fossil fuels
– High net energy yield
11. Geothermal EnergyGeothermal Energy
• Geothermal heat pumps
• Geothermal exchange
• Dry and wet steam
• Hot water
• Molten rock (magma)
• Hot dry-rock zones
12. Ocean Thermal Energy
●
Energy is available from the ocean by
– Tapping ocean currents
– Using the ocean as a heat engine
– Tidal energy
– Wave energy
13. Energy from ocean currents
●
Ocean currents flow at a steady velocity
●
Place turbines in these currents (like the
gulf stream) that operate just like wind
turbines
●
Water is more than 800 times denser
than air, so for the same surface area,
water moving 12 miles per hour exerts
about the same amount of force as a
constant 110 mph wind.
●
Expensive proposition
●
Upkeep could be expensive and
complicated
●
Environmental concerns
– species protection (including fish and
marine mammals) from injury from
turning turbine blades.
– Consideration of shipping routes and
present recreational uses of location
– Other considerations include risks from
slowing the current flow by extracting
energy.
14. The ocean as a heat engine
●
There can be a 20° difference between ocean
surface temps and the temp at 1000m
●
The surface acts as the heat source, the
deeper cold water acts as a heat sink.
●
Temperature differences are very steady
●
Florida, Puerto Rico, Hawaii and other pacific
islands are well suited to take advantage of
this idea.
●
Called OTEC (Ocean Thermal Energy
Conversion)
15. Biofuels and biodiesels
Biofuels are created from vegetable or animal based oils
(Ex: canola or soybean oil, palm oil, grease, sewage or
leftover trash) It is used and fuels for vehicles.
Biodiesel is also a type of fuel created by vegetable or
animal oils but it is often blended with regular diesel.
Biodiesel is a cleaner alternative to diesel. But not all
vehicles can use diesel.
17. Ethanol-how is it currently used and made?
• Ethanol: alcohol by
fermenting the sugars
found in plants, it is often
blended with gasoline.
• The way ethanol is
produced in the U.S. by
using corn to be produced
into ethanol.
18.
19. Biodiesel
Biodiesel is a fuel made from vegetable or animal oils that is
often blended with regular diesel fuel.
Algae as a Biofuel?
Algae grows 30 times as fast as plants and it stores up to half of its
total body mass as oil; meaning that it has a greater oil supply to use
as fuel.
Commercial use?
It is very expensive to run plants to properly culture algae, making it
a less likely source for commercial use.
