Transcript EXPERIMENTAL STUDY OF LEANED AND TWISTED HIGH …

Offshore Wind Turbines
RENEWABLE ENERGY COURSE
The group:
Pengmei WU
Fan ZOU
Aitor COLINAS
Clément BERTRAND
Loïc DELATTRE
Supervisor: Prof Göran WALL
October 2006
Summary
1° CONDITIONS OF THE OFFSHORE WIND ENERGY
2° FUNCTIONING OF OFFSHORE WIND TURBINES
3° LOCATION
4° THE ECONOMICAL ANALYSIS OF OFFSHORE WIND
FARMS
5° SOME COMPARISONS
CONCLUSION
CONDITIONS OF THE OFFSHORE WIND ENERGY
CONDITIONS OF THE OFFSHORE WIND ENERGY
THE MOST INFLUENCIAL CONDITIONS
P(W)=½*ρ*A*V3
DENSITY (ρ)
Air more dense→more
turbine energy
More air density on the
sea
SWEPT AREA (A)
ROUGHNESS
less turbulences →more
duration
Less roughness → less
shearing
CONDITIONS OF THE OFFSHORE WIND ENERGY
THE MOST INFLUENCIAL CONDITIONS
P(W)=½*ρ*A*V3
WIND SPEED (V)
Different parts
Is important to predict
wind speed variations
CONDITIONS OF THE OFFSHORE WIND ENERGY
THE MOST INFLUENCIAL CONDITIONS
EFFICIENCY
Maximum efficiency →
59%
FUNCTIONING OF OFFSHORE WIND TURBINES
HOW WIND TURBINES WORK
THE MAIN COMPONENTS: Rotor = hub +blades

A rotor: hub + 3 blades
 Blades made of:
• wood,
• synthetic composites
(polyester or epoxy reinforced
by glass fibres),
• metals (steel or aluminium
alloys).
 Blades length : between 20- 60
metres.
Source: www1.eere.energy.gov
HOW WIND TURBINES WORK
THE MAIN COMPONENTS: Gear box, generator
Source: www1.eere.energy.gov

A gear box:
• Connects the low-speed shaft
to the high-speed shaft.
• Raises the rotational speeds
from about 30 to 60 rotations
per minute to 1200 to 1500 rpm.

A three phase asynchronous
generator:
• Works with the wind turbine
rotor which supplies very
fluctuating mechanical power
but at the output ensures that
the output frequency is locked
to that of the utility.
• Sends the current through a
transformer.
Source: js.efair.gov.cn
Source:www.windmission.dk/workshop
/
HOW WIND TURBINES WORK
THE MAIN COMPONENTS: Yaw drive, tower

A yaw drive:
• aligns the machine with the
wind.
•sensors activate the yaw
control motor which rotates the
turbine .

A tower:
• Supports the nacelle
assembly and elevates the
rotor.
•withstands significant loads,
from gravitational, rotational
and wind thrust loads
• Its length is between 30 - 80
meters.
Source: www1.eere.energy.gov
HOW WIND TURBINES WORK
CONTROL SYSTEMS

Control systems permit to start up when the wind
speed is sufficient or to turn off the machine at about
high speeds to prevent overheating of the generator.
 We use a electronic controller which measures:
 Voltage;
 Current;
 Frequency;
 Temperature inside the nacelle;
 Generator temperature;
 Gear oil temperature;
 Wind speed;
 The direction of yawing;
 Low-speed shaft rotational speed;
 High-speed shaft rotational speed;
HOW WIND TURBINES WORK
SAFETY SYSTEMS
Source:web.abqtrib.com/art/news05
 The first safety device is the
vibration.It consists of a ball
resting on a ring.
 It’s important to stop
automatically the wind turbine in
case of dysfunction of a critical
component.
 we can use:
 the aerodynamic braking system
which consists in turning the rotor
blades about 90 degrees.
The mechanical braking which is
a disc brake placed on the
gearbox high-speed shaft.
LOCATION AND ENVIRONMENTAL IMPACTS
LOCATION
WHERE AND WITH WHAT MATERIALS?
WHERE:
- The Department of Marine has indicated that a minimum
distance of 5km offshore is appropriate
-
Wind turbines can be installed until several hundreds meters
of deepth
MATERIALS:
- Steel is more competitive than concrete
-
The metal parts of the turbine structures is specially coated
to protect them from corrosion
-
the voltage of undersea cables can reach 150kV
LOCATION
WHAT KIND OF FOUDATIONS?
Concrete or steel
3,5 to 4,5m of diameter
LOCATION
WHAT KIND OF FOUNDATIONS?
Available for deep water
LOCATION
WHAT KIND OF FOUNDATION?
THE ECONOMICAL ANALYSIS OF OFFSHORE WIND
FARMS
Introduction
• Offshore windpower as clean, free and renewable
energy,most countries in world pay attention to it.
Moreover,its capacity is huge.
• Quantitative research and analysis for the technical and
economic benefits of offshore windpower is an important
topic. It is helpful to the rational use and development of
offshore windpower.
A Initial Investment
a The costs of technical and economic
feasibility study and design expenses
b The costs of offshore windpower
turbine and transportation
c Foundation cost and installation cost
d The costs of grid connection
e Other cost
B Operating Costs
a The costs of materials (parts, lubricants,
etc.)
b The operation and maintenance costs
c The management cost
d Power generation costs
C Total Revenue
Influencing factor of the costs
• Distance to shore and water depth are one of the most
important influencing factor on the cost of offshore
windpower farms. It will affect foundation cost.
The calculation of economic analysis
• NPV(Net Present Value): It refers to the difference of
cost between the total output value and the current value of
total value, in their effective use of n-year period.
• Obviously, the NPV is below zero, and its economy is poor;
NPV is zero, the inputs and outputs is same; NPV is above
zero, its economy is good. The greater of its value, the better
of its economy.
• Net annual output value = Annual Production Value Depreciation - Operating Expenses – Other Expenses
• Depreciation: It is the loss of capital asserts. It is currency
performance of the labor loss.
• It can be simply expressed as:Dj = m*(P0 / n)
• Dj——Depreciation of j year, j=1,2,3,…n , Depreciation Year.
• P0——Costs per kilowatt
• m——Total installed capacity
Example
• The conditons of this
offshore windpower farm
are as follows:
• Source:http://www.dtzzfd.c
n/fdxx.asp)
Single
capacity
(kw)
Numbers
Height(m)
300
32
30
500
40
35
600
78
40
750
10
50
•
•
•
•
•
Total installed capacity: m = 8.39×104 kw
Costs per kilowatt:
P0 = 9300 RMB/kw
Life-span :
n = 20 year
Then: Depreciation
Dj = 9300×8.39×104/20
=3.9×109RMB/Year
Statistics of costs
Costs
Percentage (%)
Depreciation
82.6
The expenses of materials
6
The operation and
maintenance expenses
The management expenses
4.8
Total
100
Source:www.dtzzfd.cn/fdxx.asp
6.6
• Therefore, the annual costs: 3.9×109/82.6% =
4721.5×108 RMB
• Power Output of Last Year: 1.8×108 kwh
• The Costs per kwh: 4721.5×104/1.8×108 = 0.262
RMB
Some possible ways to reduce the costs of wind power
• Increase single capacity and the turbine number of a
offshore wind farm.
• Reduce the cost per kilowatts.
• Mass production can reduce unit cost.
• Increase generating capacity
• Reduce the development cost of electricity.
• Reasonable protection to increase life span.
SOME COMPARISONS
Comparison of onshore and offshore wind power
Installed Cost
Offshore system is 30%--70% higher than onshore system
Efficiency
Offshore system is higher than onshore system
Wind speed
Higher in offshore
Life time
Offshore system has Longer life time
Installed capacity
Offshore is up to 50% more capacity
Environment impact
Offshore has less impact
Advantage
Available of large continuous areas
Higher wind speeds, less turbulence,
Less environment impact
Disadvantage
High cost to set and maintain
Conditions are harsh and corrosive some time
Hard to reâir a broken down turbine in open watars
Wind power capacity of the world
Development of the wind energy over the world
Annual Wind Power Development
Wind power capacity of different countries
Installed wind power capacity per person in Europe
CONCLUSION
TACK SA MICKET!