wind energy lecture 1

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 1/42

Lebanese University, Faculty of Engineering

Mechanical Engineering Department 

Wind Energy

Lecture Notes For

Mechanical Engineering Students

2014 - 2015

12/29/2014 1Bassam Riachi

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 2/42

12/29/2014 Bassam Riachi 2

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 3/42

References

1- Renewable and Efficient Electric Power

Systems, Gilbert M. Masters

2- Wind Energy Explained, J.F.Manuel

3- Aerodynamics of Wind Turbines, Martin

4- Renewable Energy Fundamentals, Bistritski

12/29/2014 Bassam Riachi 3

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 4/42

12/29/2014 Bassam Riachi 4

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 5/42

12/29/2014 Bassam Riachi 5

• Wind power could generate up to 18% of the world’s

electricity by 2050, compared with 2.6% today.

• The nearly 400 gigawatts of current wind powerworldwide must increase eight- to ten-fold to achievethe IEA roadmap’s vision. 

•  It sees China overtaking OECD Europe as the leadingproducer of wind power by 2020 or 2025, with theUnited States ranked third.

•  Wind power deployment under this vision would saveup to 4.8 gigatonnes of CO2 emissions per year by 2050

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 6/42

Top 15 countries

by nameplate wind power capacity

12/29/2014 6Bassam Riachi

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 7/42

Top 10 countries by wind power

electricity production [2012]

12/29/2014 7Bassam Riachi

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 8/42

Wind energy cost

Fixed / Initial + Operating

• The cost of a wind system has two components:

initial installation costs and operating expenses.

• The initial installation cost includes the purchase

price of the complete system (including tower,wiring, utility interconnection or battery storage

equipment, power conditioning unit, etc.) plus

delivery and installation charges, professionalfees and sales tax.

12/29/2014 Bassam Riachi 8

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 9/42

Operating costs

• Operating costs include maintenance and

service, insurance and any applicable taxes.

• A rule of thumb estimate for annual operating

expenses is 2% to 3% of the initial system cost.

• Another estimate is based on the system’s

energy production and is equivalent 1 to 2

cents per kWh of output.

12/29/2014 Bassam Riachi 9

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 10/42

Cost of installed KW

• A grid-connected residential-scale system (1-10 kW) generally costs between $2,400 and$3,000 per installed kilowatt.

• A medium-scale, commercial system (10-100kW) is more cost-effective, costing between$1,500 and $2,500 per kilowatt.

•

Large-scale systems of greater than l00 kWcost in the range of $1,000 to $2,000 perkilowatt

12/29/2014 Bassam Riachi 10

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 11/42

Calculating the Cost Per kWh

12/29/2014 11Bassam Riachi

 Annual Cost = (Initial Cost/Expected Life) +

Annual Operating Costs

Wind turbine manufacturers estimate a useful

life of between 20 and 30 years for their

product.

• Cost Per kWh = Annual Cost/Annual Energy

Output

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 12/42

example

12/29/2014 12Bassam Riachi

• Annual cost = ($100,000/25 years) +

$1,000/year = $4,000 + $1,000 = $5,000/year

• Cost per kWh = ($5,000/year)/100,000

kWh/year = $0.05 per kWh

• US cost: 2.5 – 5 cents per KWh

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 13/42

Cost comparison based on levelized

energy costs LEC

12/29/2014 Bassam Riachi 13

The LEC represents the total cost

to build and operate a new power

plant over its life divided to equal

annual payments and amortizedover expected annual electricity

generation.

It reflects all the costs including

initial capital, return oninvestment, continuous operation,

fuel, and maintenance, as well as

the time required to build a plant

and its expected lifetime

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 14/42

Lifecycle greenhouse gas emission estimates for

electricity generators, according to Benjamin K.

Sovacool's comparison

12/29/2014 Bassam Riachi 14

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 15/42

World’s First Wind Turbine 

12/29/2014 Bassam Riachi 15

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 16/42

12/29/2014 Bassam Riachi 16

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 17/42

https://www.youtube.com/watch?v=llIbjC49Fjs 

12/29/2014 Bassam Riachi 17

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 18/42

http://www.energy.gov/eere/wind/how-does-wind-turbine-work 

12/29/2014 Bassam Riachi 18

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 19/42

12/29/2014 Bassam Riachi 19

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 20/42

Types of Wind Turbines

12/29/2014 Bassam Riachi 20

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 21/42

The cost of a turbine

increases roughly in

proportion to blade

diameter, but power isproportional to

diameter squared, so

bigger machines have

proven to be more costeffective.

12/29/2014 Bassam Riachi 21

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 22/42

12/29/2014 Bassam Riachi 22

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 23/42

12/29/2014 Bassam Riachi 23

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 24/42

12/29/2014 Bassam Riachi 24

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 25/42

 ρ = f (p,T)

12/29/2014 Bassam Riachi 25

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 26/42

12/29/2014 Bassam Riachi 26

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 27/42

12/29/2014 Bassam Riachi 27

USA

Europe

Impact of Tower Height

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 28/42

12/29/2014 Bassam Riachi 28

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 29/42

12/29/2014 Bassam Riachi 29

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 30/42

• For large machines, when a blade isat its high point, it can be exposed tomuch higher wind forces than whenit is at the bottom of its arc.

• This variation in stress as the blademoves through a complete revolutionis compounded by the impact of thetower itself on wind speed-especiallyfor downwind machines, which havea significant amount of windshadowing as the blades pass behindthe tower.

• The resulting flexing of a blade canincrease the noise generated by the

wind turbine and may contribute toblade fatigue, which can ultimatelycause blade failure.

12/29/2014 Bassam Riachi 30

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 31/42

12/29/2014 Bassam Riachi 31

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 32/42

12/29/2014 Bassam Riachi 32

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 33/42

12/29/2014 Bassam Riachi 33

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 34/42

12/29/2014 Bassam Riachi 34

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 35/42

12/29/2014 Bassam Riachi 35

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 36/42

12/29/2014 Bassam Riachi 36

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 37/42

12/29/2014 Bassam Riachi 37

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 38/42

• For a given wind speed, rotor efficiency is a function ofthe rate at which the rotor turns.

•   If the rotor turns too slowly, the efficiency drops offsince the blades are letting too much wind pass by

unaffected.• If the rotor turns too fast, efficiency is reduced as the

turbulence caused by one blade increasingly affects theblade that follows.

• The usual way to illustrate rotor efficiency is to present

• it as a function of its tip-speed ratio (TSR).

• The tip-speed-ratio is the speed at which the outer tipof the blade is moving divided by the wind speed.

12/29/2014 Bassam Riachi 38

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 39/42

12/29/2014 Bassam Riachi 39

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 40/42

12/29/2014 Bassam Riachi 40

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 41/42

  A 40-m, three-bladed wind turbine produces 600 kWat a wind speed of 14 m/s. Air density is the standard1.225 kg/m3. Under these conditions:

a. At what rpm does the rotor turn when it operates

with a TSR of 4.0?

b. What is the tip speed of the rotor?

c. If the generator needs to turn at 1800 rpm, whatgear ratio is needed to match the rotor speed to thegenerator speed?

d. What is the efficiency of the complete wind turbine(blades, gear box, generator) under these conditions?

12/29/2014 Bassam Riachi 41

8/19/2019 Wind Energy Lecture 1

http://slidepdf.com/reader/full/wind-energy-lecture-1 42/42