1. renewable energy is energy which comes from natural resources such as sunlight, wind, rain,...
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Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable.
Climate change concerns, high oil prices, and increasing government support, accelerates the growth of this sector.
In 2008, about 19% of global final energy consumption came from renewable sources.
With nations pledging to reduce the carbon emission to counter global warming, the need for systems that generate renewable energy has been
on a rise.
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Wind power is the conversion of wind energy into a useful form of energy, such as
wind turbines to make electricity, wind mills for mechanical power, wind pumps for pumping water or drainage, sails to propel ships Wind energy has been the world’s fastest growing source of
electricity during the past decade, with over 20% annual growth
Energy production from wind was 340 TWh, which is about 2% of worldwide electricity usage.
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A wind turbine is a rotary device that extracts energy from the wind.
If the mechanical energy is used directly by machinery the
machine is called a windmill.
If the mechanical energy is instead converted to electricity, the machine is called a wind generator.
A wind farm is a group of wind turbines in the same location used for production of electric power.
Wind farms and wind turbines are built onshore as well as offshore.
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A floating wind turbine is an offshore wind turbine mounted on a floating structure.
As of December 2009, there have been two operational floating wind turbines
BLUE -H 80 kW 21 km off the coast in waters 113 meters deep, southeast of
Italy.
HYWIND 2.3 mW 10 km off the coast of Karmoy, Norway in 220-m deep waters.
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Power Output from a wind turbine is proportional to the cube of wind velocity
and to the square of the rotor diameter.
The wind can be stronger up to 10 m/sec and steadier over water due to the absence of topographic features.
Existing fixed-bottom wind turbine technology deployments had been limited to water depths of 30-meters.
Worldwide wind resources are abundant over deep-waters.
Wind should be steady and consistent for the smooth working of turbines.
Noise and visual pollution created by fixed turbines near the costal areas are to be avoided.
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Simplified wind turbine model.
Maximum Power
ConstantPower
0 5 10 15 20 250
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2
3
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Relative wind velocity [m/s]
Pow
er [
MW
]
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Wind velocity increases from lighter to darker shade.From 1m/s to 10 m/s
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Floating platforms can be classified into.
single-turbine-floater (one wind turbine mounted
on a
floating structures). multiple turbine floater (multiple wind turbines
mounted
on a floating structures)
The electricity generated is sent to shore through undersea HVDC
cables.
There are mainly three types of systems used for station keeping for the turbine.
Barge System ,Spar Buoy System ,Tension Leg System10
Barge Systems
Spar Buoy Systems
Tension Leg Systems
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It is the process of fixing the floating structure to the seabed. Absorb dynamic loads, transfer load to seabed
TWO TYPES- Catenary Taut leg
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Hydrodynamic loads
Aerodynamic loads
• Horizontal and Vertical loads
• Dynamic and static loads
Higher wind velocities allow higher capacity turbines to be installed.
Thus giving much more power output per installation when compared to fixed turbines.
Lower Offshore Wind Turbulence – Longer Turbine Life ~ 25-30 Years
Wind is- Free Inexhaustible Environmentally Friendly Clean Safe & Cost Effective Energy Source.
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Huge initial cost when compared to other renewable energy sources.
The economics of deepwater wind turbines will be determined by the costs of the floating structure and power distribution system when compared to a fixed turbine.
Enough buoyancy to support the weight of the turbine and to restrain pitch, roll and heave motions .
Only at few sites with high wind speeds can compete economically
with conventional power production ,at present.
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Offshore construction is more complicated and it should survive severe marine environments.
Maintainace is high when compared to on-shore turbines.
Complexity of the system.
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Blue H has successfully decommissioned the unit as they are planning to build a 38-unit deepwater wind farm at the same location.
The US State of Maine will be soliciting proposals in September 2010 to build the world's first floating, commercial wind farm.
Portugal govt is partnered with Principle Power to install a multi-megawatt full-scale floating wind turbine off the coast of Portugal in 2011.
The enormous wind energy resource offshore, covering more than 70% of the Earth’s surface, can be effectively tapped resulting in a cleaner and smarter energy …
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