Title: DESIGN OF A SOLAR-WIND HYBRID POWER SYSTEM
1DESIGN OF A SOLAR-WIND HYBRID POWER SYSTEM
- By Prad Pathirana
- Advised by Prof. Richard Wilk
2Presentation Outline
- Background
- Target Location
- Project Description
- Savonius Type Wind Turbine
- Wind Tunnel Testing
- Results
- Lessons Learned
- Bill of Materials
- Timeline
- Future Plans
- Acknowledgements and References
3Background
- Rural coastal communities in Sri Lanka lack basic
lighting and ventilation - Kerosene and car batteries are used for lighting
and short term electricity sources. - Risk of fire and health issues
- Due to the proximity to the sea and being on the
equator, the location is ideal for solar and wind
power generation
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4Location Wind Data
- Sea breeze, land breeze patterns are present
throughout the day - 10-15 mph wind on average
- Day Air flows in from the sea to land
- Night Air flows in from the land to sea
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5Location Solar Data
- Solar irradiation on a horizontal surface is
approximately 7 kWh/m2/day - The terrain near the sea is flat thus no
obstruction to sunlight - Latitude 7 00 NLongitude 81 00 E
- A solar panel facing up would be very effective,
and tracking systems would be unnecessary
Sri Lanka
6Project Description
- Design a system that will harness the wind and
solar energy available on location - Main goal is to provide basic lighting and
ventilation - The system will be a direct current based system
- Solar panel may have some concentrating
capabilities to capture low angle sunlight - LED lighting will be used
- Small DC fan to enhance ventilation
- Aim to generate 70-100W of power
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7Design Schematic
8Savonius Type Vertical Axis Wind Turbine
- Wind direction does not affect performance
- More torque generated in comparison to other VAWT
- Simple design
- Less efficient
http//www.hobbithole.net/Portals/1/savonius_rotor
_with_measures_better_more.JPG
www.symscape.com/blog/vertical_axis_wind_turbine
9Wind Tunnel Testing
Front
Top mount
Bevel Gears
10Wind Tunnel Testing
- Measured (at different wind speeds)
- RPM
- Power
- Torque
Basic blades with variable spacing
11Results - rpm
Wind Speed Wind Speed Wind Speed Blade Speed Blade Speed
Hz m/s Re Hz RPM
1 0.70 8123 0 0
2 1.41 16247 0 0
3 2.11 24370 0 0
4 2.81 32494 0 0
5 3.52 40617 0 0
6 4.22 48759 1.26 75.6
7 5.02 58029 1.89 113.4
8 5.83 67299 2.4 144
9 6.63 76569 2.85 171
10 7.43 85839 3.37 202.2
11 8.33 96229 5.7 342
Testing was performed with no bevel gear
attachment, free spinning
12Results - power
Wind speed(m/s) Power (W)
7.43 0.02
8.33 0.02
9.23 0.08
10.13 0.12
11.03 0.27
Transients effected measurements
13Results gear efficiency and torque
Gear efficiency
Torque
 No Gears No Gears With Gears With Gears gear ?
 hz m/s hz m/s gear ?
To start rotating 6.2 4.52 8.8 6.48 0.70
Maintain rotation 5.5 4.01 7.8 5.59 0.71
     0.70
Wind speed Mass Torque
m/s grams N.m
7.43 90 0.0247
8.33 105 0.0288
9.23 130 0.0357
10.13 160 0.0439
11.03 190 0.0522
14Lessons learned
- Wind tunnel testing gave an idea on how stresses
act on a typical Savonius type blade - Rough idea of how gears effect RPMs
- Using non-dimensional factors with the results
can predict numbers for a larger model - Wind flow in the wind tunnel is in one direction,
thus the multidirectional wind harnessing
capacity of the VAWT cannot be explored - At very high wind speeds the VAWT may become a
safety hazard
15Bill of Materials
Wind turbine
Wind (scoops) Savonius type blades x2 30
Generator Great Lakes Electr.Corporation (Ametek 30V) 99.99
Gearbox The exact size is to be determined 100
Solar Panel
Panel (BP350J) BP Solar 50W panel2 340
Circuitry
Charge controller Silicon Solar (SKUÂ 06-1024)2 34.95
Voltage Converter 6-14V In-11-26 Out Voltage3 39.95
Battery 12V 36Ah Deep discharge battery 64
Battery meter MINN KOTA MK-BM-1D 16.18
Wiring 16 gage (30 ft) 20
Materials
Circuit box Aluminum box (Mcmaster Carr)1 30
Angled Aluminum Metal frame 80
Electrical components Switches, lights, etc. (All electronics)4 45
TOTAL TOTAL 900.07
- Mcmaster Carr. (www.mcmaster.com)
- Silicon Solar (www.siliconsolar.com)
- Jaycar Electronics (http//www.jaycar.com/)
- All Electronics (http//allelectronics.com/)
IEF Funding 535
16Timeline (Fall 2008)
- To do
- Test different blade designs
- Test different blade spacing
17Future Plans
- Order core parts over the winter break
- Charge controller
- Generator
- Voltage converter
- Experiment on the effects of blade spacing on the
overall performance - Predict performance of actual VAWT using data
collected from the wind tunnel tests - Design actual Solar-Wind hybrid system
- Manufacture
18Acknowledgements
- Prof. Richard Wilk
- Stanley Gorksi
- Paul Tompkins
19References
- Gupta, R., R. Das, and K.K. Sharma. Experimental
Study of a Savonius-Darrieus Wind Machine. Assam - Sheldahl, R.E. Blackwell, B.F. Feltz, L.V.
Wind tunnel performance data for two- and
three-bucket Savonius rotors. Sandia Labs.,
Albuquerque, NM. 1978 - Yunus A. Cengel and John M. Cimbala , FLUID
MECHANICS Fundamentals and Applications