Sustainable Energy Workshop

1. Sustainable Energy Workshop Palestine Polytechnic University May 10-13 2010 Hebron, Palestine

2. Day Two Agenda

3. Day Two Agenda(detailed) Sustainable Energy Resources- PESPRU

4. Sameer Khader Associate Professor, Ph.D, EE, Visiting professor- University of Hartford, Connecticut, USA Department of Electrical and Computer Engineering College of Engineering and Technology Palestine Polytechnic University (PPU) ACKNOWLEDGMENT The instructor would like to thank the Open Society Institute (OSI), and USAID- AMEDEAST for fully sponsoring the visit to university of Hartford according to Palestinian Faculty Development Project ( PFDP). ACKNOWLEDGMENT The instructor would like to thank Hartford university administration and Prof. Cay Yavuzturk / university of Hartford for his valuable lectures in this field , and support .

5. OUTLINE ALTERNATIVE CLEAN ENERGY RENEWABLE ENERGY CONSUMPTION WIND ENERGY GROWTH ENERGY COST & PRESPECTIVES SUMMARY

6. ALTERNATIVE CLEAN ENERGY Wind Solar, Tide and Wave Hydroelectric Biomass and Waste The total energy generated by renewable resources by 2008 was: 3472.70261 Billion kWhr Sustainable Energy Resources- PESPRU 6

7. Wind Energy What is the cause of the wind: Differences in atmospheric pressure due to differences in temperature are the main cause of wind. Because warm air rises, when air fronts of different temperatures come in contact, the warmer air rises over the colder air, causing the wind to blow. Wind generators take advantage of the power of wind. Long blades, or "rotors", catch the wind and spin. Like in hydroelectric systems, the spinning movement is transformed into electrical energy by a generator. The placement, or "siting" of wind systems is extremely important. In order for a wind-powered system to be effective, a relatively consistent wind-flow is required. Obstructions such as trees or hills can interfere with the rotors.

8. Wind Energy Cont’d There are certain minimal speeds at which the wind needs to blow. For small turbines it is 13 Km/hr ( 3.6 m/s). Large plants require speeds of 20 Km/hr ( 5.6 m/s). Problems : One of the main problems with wind power is the space that is used up by the so-called "wind farms." In some cases, the space taken up can seriously alter the environment. The good news is that although wind farms require a great deal of square mileage, there is quite a bit of space between the actual wind machines. This space can be used for agricultural purposes. Another problem with wind power is that relatively speaking, it does not generate very much energy for the price. Perhaps this setbackis made up for in friendliness to the environment. Sustainable Energy Resources- PESPRU

9. RENEWABLE ENERGY CONSUMPTION , 2008 http://en.wikipedia.org/wiki/World_energy_resources_and_consumption Sustainable Energy Resources- PESPRU

10. RENEWABLE ENERGY CONSUMPTION ,…cont’d Renewable Energy at the end of 2008 compared with other resources. http://www.eia.doe.gov Sustainable Energy Resources- PESPRU

11. WIND ENERGY GROWTH WIND ENERGY GROWTH The energy harvested form the wind has stable growth. For example in 2007 it was ~35 Billion Kilowatt-hours . Sustainable Energy Resources- PESPRU 11

12. WIND ENERGY GROWTH, …cont’d Sustainable Energy Resources- PESPRU

13. ENERGY COST & PRESPECTIVES The cost of PV energy by the year of 2010 is expected to drop to 47 $/MWhr Sustainable Energy Resources- PESPRU

14. ENERGY COST & PRESPECTIVES……cont’d Electricity Generation Costs ~~ , ¢/kWh Combined cycle gas turbine 3-5 Wind 4-7 Biomass gasification 7-9 Remote diesel generation 20-40 Solar PV central station 20-30 Solar PV distributed 20-50¢/kWh Despite the highest cost of 1kWhr energy extracted by the solar irradiation, this source is the most sustainable and its energy cost continues to drop down due to high investment rate, strategic support, and world wide cooperation in this sector. When the environmental and social costs of power generation are considered, the economics of solar electricity becomes attractive. Sustainable Energy Resources- PESPRU

15. SUMMARY One day fossil resources will be over , and we must prepare economy, industry, and community to invest in the infinity clean and friendly to the environment resources. Sustainable Energy Resources- PESPRU

16. Presentation#2 : WIND ENERGY Ancient Resource Meets 21st Century 16

17. Presentation#2 : INTRODUCTION TO WIND ENERGY Wind Turbines, Power for a House and City

18. Wind Energy Outline INTRODUCTION TO WIND ENERGY HISTORICAL PREVIEW TYPES AND CLASSIFICATIONS WIND TURBINE CONSTUCTION POWER IN THE WIND/MODELING WEIBULL DISTRIBUTION WIND TURBINE OPERATION WIND FARMS WIND ENERGY CHALENGES WIND FARMS ECONOMICS CONCLUSION Sustainable Energy Resources- PESPRU 18

19. INTRODUCTION TO WIND ENERGY CAUSE : When air fronts of different temperatures come in contact, resulting different air pressure,…. Wind blowing

20. Wind Turbine Description

21. HISTORICAL PREVIEW • 1 A.D. • Hero of Alexandria uses a wind machine to power an organ and moving tools. • ~ 400 A.D. • Wind driven Buddhist prayer wheels • 1200 to 1850 • Golden era of windmills in western Europe – 50,000 : 9,000 in Holland; 10,000 in England; 18,000 in Germany • 1850’s • Multiblade turbines for water pumping made and marketed in U.S. • 1882 • Thomas Edison commissions first commercial electric generating stations in NYC and London • 1900 • Competition from alternative energy sources reduces windmill population to fewer than 10,000 • 1850 – 1930 • Heyday ( peak production) of the small multi blade turbines in the US Midwest • as many as 6,000,000 units installed • 1936+ • US Rural Electrification Administration extends the grid to most formerly isolated rural sites and grid electricity rapidly displaces multi blade turbine uses.

22. TYPES AND CLASSIFICATIONS Turbines can be categorized into two overarching classes based on the orientation of the rotor Vertical AxisHorizontal Axis

23. TYPES AND CLASSIFICATIONS • Vertical axis wind turbines • - have their axis of rotation vertical to the ground and almost perpendicular to the wind direction. • - can receive wind from any direction; therefore complicated yaw device can be eliminated. • - have generator and the gearbox are housed at the ground, which make the tower design simple and more economical. • - have ground level maintenance. • - have no need of pitch control when used for synchronous applications. • Also there are a lot of disadvantages: • They are not self-starting, additional mechanism may be required to push and start the turbine. • Guy wipes are required to support the tower structure which may pose some practical difficulties.

24. TYPES AND CLASSIFICATIONS • Horizontal axis wind turbines • - have their axis of rotation horizontal to the ground and almost parallel to the wind stream . • - most of the commercial wind turbines fall under this category. • This type machines has some distinct advantages • low cut-in wind speed • easy furling ( rotating) and manufacturing. • they have high power coefficient, which make them good advantage in design of large power plants. • Also there are a lot of disadvantages: • they have complicated and expensive design because of the generator and the gearbox are placed over the tower in the nacelle. • the need for tail (yaw) drive to orient the turbine towards turbine.

25. HORIZONTAL WIND TURBINE CLASSIFICATIONS Horizontal WT can be classified into three types : • Single blade; • Two blades • Three blades • Multi blades These turbines are characterized with high power coefficient and extended extracted power range, but needs high advanced ratio ( high wind speed). Single and two-blades are rarely used due to the need of counter weight. Three-blades turbine are mostly used and commercially available.

26. VERTICAL WIND TURBINE CLASSIFICATIONS Vertical WT can be classified into three types : • Darrieus • Savonius • Musgrove These turbines are characterized with low Power coefficient and limited extracted power, but in the mean time have with low advanced ratio ( low wind speed), which is good indicator.

27. Number of Blades – One • Rotor must move more rapidly to capture same amount of wind • Gearbox ratio reduced • Added weight of counterbalance negates some benefits of lighter design • Higher speed means more noise, visual, and wildlife impacts • Blades easier to install because entire rotor can be assembled on ground • Captures 10% less energy than two blade design • Ultimately provide no cost savings. • Has not accepted visual form.

28. Number of Blades - Two • Advantages & disadvantages similar to one blade turbine. • Need teetering (balancing) hub and or shock absorbers because of gyroscopic imbalances • Capture 5% less energy than three blade designs. • Generate additional vibrations &noises.

29. Number of Blades - Three • Balance of gyroscopic forces • Slower rotation • increases gearbox & transmission costs • More aesthetic ( nice view), less noise, fewer bird strikes.

30. WIND TURBINE CONSTUCTION

31. WIND TURBINE CONSTUCTION …cont’d

32. FUNCTIONS OF WIND TURBINE PARTS The Nacelle: this is the machine corpus mounted on the tower, and contains all the machine elements. Rotor: this is, three-blades ( may more or less) diameter that swept in the air. Blades; are made from light material with pitch angle. The pitch mechanism on the blades adjusts the angle of the blades to be in the wind direction and to maximize the extracted power. Low- speed shaft: this is a steel shaft connected with the plate, rotates at low speed with high torque, and transmit the speed to the next stage (high speed stage). Gear box: change the speed form low rate to the high rate values ( high speed) suitable for the electrical generator operation. High-speed shaft: used to rotate the generator at high speed with purpose to generate the required voltage and electrical frequency.

33. FUNCTIONS OF WIND TURBINE PARTS, ..cont’d Generator: This either DC or AC generator that converts the input mechanical power in terms of torque and speed into output electrical power in terms of voltage and current ( electrical energy). Brake: this an electromechanical system that acts on the low-speed shaft with purpose braking the turbine in emergency case or when the speed falls below the cut-in value or raised up above the cut-out value. Yaw drive and Yaw motor: are used to keep the plane of the blades oriented into the wind. Anemometer: wind measurement device used to measure the speed value and direction. Wind vane: used to direct the nacelle toward the wind direction. Tower: this a cement construction used to carry on all the equipments

34. WIND TURBINE CONSTUCTION and MATERIALS • Wood • Strong, light weight, cheap, abundant, flexible • Popular on do-it yourself turbines • Solid plank • Laminates • Veneers • Composites

35. Blade Composition Metal • Steel • Heavy & expensive • Aluminum • Lighter-weight and easy to work with • Expensive • Subject to metal fatigue

36. Blade Construction Fiberglass • Light weight, strong, inexpensive, good fatigue characteristics • Variety of manufacturing processes • Cloth over frame • Filament winding to produce spars • Most modern large turbines use fiberglass

37. Large Wind Turbines • 450 ft ( 130m)base to blade • Each blade 112 ft (35m) • Span greater than Booing 747 • 163 tons total weight • Foundation 20 feet deep (7m) • Rated at 1.5 – 5 megawatt • Supply at least 350 homes

38. Wind Turbine Montage

39. Rotor Solidity Solidity is the ratio of total rotor plan- form area to total swept area Low solidity (0.10) = high speed, low torque High solidity (>0.80) = low speed, high torque R a A Solidity = 3a/A

40. Power= 1/2 x air density x swept rotor area x (wind speed)3 A V3  POWER IN THE WIND / MODELING Density = P/(RxT) P - pressure (Pa) R - specific gas constant (287 J/kgK) T - air temperature (K) Area =  r2 Instantaneous Speed (not mean speed) kg/m3 m2 m/s Where : Swept Area: A = πR2 Area of the circle swept by the rotor (m2). R

41. POWER IN THE WIND / MODELING, …cont’d • This power depends on : • The swept area, A • Wind speed, V • ( cube of this speed) • Air density,  Power in the Wind = ½ρAV3 R R

42. POWER IN THE WIND / MODELING, …cont’d • Wind Speed • Wind energy increases with the cube of the wind speed • 10% increase in wind speed translates into 30% more electricity • Twice time increase in the wind speed translates into eight time increase in the generated electricity • Height • Wind energy increases with height to the 1/7 power • Twice time the height translates into 10.4% more electricity, because as the tower high increases the cold air has high density, and it help in moving the blades.

43. POWER IN THE WIND / MODELING, …cont’d • Air density • Wind energy increases proportionally with air density • Humid climates have greater air density than dry climates • Lower elevations have greater air density than higher elevations • Blade swept area • Wind energy increases proportionally with swept area of the blades • Blades are shaped like airplane wings • 10% increase in swept diameter translates into 21% greater swept area • Longest blades up to 413 feet in diameter • Resulting in 600 foot (200m) total height

44. POWER IN THE WIND / MODELING, …cont’d • The Lift Force is perpendicular to the direction of motion. We want to make this force BIG. • The Drag Force is parallel to the direction of motion. We want to make this force small. α = low α = medium <10 degrees α = High Stall!!

45. Airfoil Shape Just like the wings of an airplane, wind turbine blades use the airfoil shape to create lift and maximize efficiency.

46. Twist & Taper • Speed through the air of a point on the blade changes with distance from hub • Therefore, tip speed ratio varies as well • To optimize angle of attack all along blade, it must twist from root to tip Fastest Faster Fast

47. ΩR V TSR = Tip-Speed Ratio ΩR Tip-speed ratio is the ratio of the speed of the rotating blade tip to the speed of the free stream wind. There is an optimum angle of attack which creates the highest lift to drag ratio. Because angle of attack is dependant on wind speed, there is an optimum tip-speed ratio R Where, Ω = rotational speed in radians /sec R = Rotor Radius V = Wind “Free Stream” Velocity

48. Betz Theory : According to Albert Betz / German Scientist,1928 theorem, the question is : How much available and reasonable power can be extract from wind turbine with concrete design ?. The Betz analysis uses an actuator disk approach.

49. Actuator Disk Analysis This Analysis depicted three distributions :

50. High pressure at P1 & P2 Pressure and velocity variations Wind stream Output velocity Input wind velocity Cross-section distribution