1. Small Wind Electric Systems Wind Turbine Electrical Output – Electricity from a spinning shaft Balance of Systems – Types – Components

2. First Things First. What does a small wind turbine produce? Wild Alternating Current (Wild AC) – “Wild” due to the fluctuating voltage, current and frequency. – Why is this? Most modern small wind turbines are direct drive permanent magnet systems (there are exceptions) – In most cases the wild AC needs to be rectified. Conversion of Alternating Current (AC) to Direct Current (DC) WILD ACDC 120 AC @ 60Hz

3. Electricity from a Spinning Shaft http://www.reuk.co.uk/OtherImages/moving-magnet-past-wire-to-make-current.jpg Click Here for Animation

4. Why Alternating Current? Simplicity of permanent magnets alternators This AC power is rectified to Direct Current regardless of battery or grid-tie configuration. 3 phase output is most common http://bp1.blogger.com/_Ist6QgbdKFo/SIsThFlYcTI/AAAAAAAAAGw/-cBy0MQjDvI/s400/5.bmp

5. Why Three Phase? Most effective use of space and materials!

6. Axial Flux PM Alternators http://flyingv.ucsd.edu/nima/Axial_Flux/motor_cad.jpg

7. Small Wind Systems Small Wind Systems: Battery (off-grid) systems Grid-Tie with battery backup systems Batteryless / Direct grid-tied systems Direct Drive Batteryless Systems

8. Battery (off-grid) systems Regulation and Conversion

9. Battery (off-grid) systems Controller

10. Off-Grid Hybrid System Combines multiple DC charging systems

11. Battery (off-grid) Hybrid system Controller

12. Benefits of Hybrid Systems? Wind and solar compliment one another! 400 350 300 250 200 150 100 JanFebMarAprMayJunJulAugSepOctNov Dec Hours of sunshine or average wind power (Watts/m 2 ) Average wind power Data from SE Iowa Hours of Sunshine

13. PV modules and wind turbine (no generation) Battery (storage) Loads (utilization) PV modules and wind turbine (active generation) Summer Winter Battery (storage) Loads (utilization) The Effects of Seasons on Hybrid Power Systems

14. Grid-Tie with Battery Backup Controller

15. Grid-Tie with Battery Backup Benefits: – Potential sale of excess energy – Battery backup during electrical grid failure – Incentives supported Downfalls: – Expensive – Added maintenance (batteries)

16. Batteryless / Direct Grid-Tie Systems Controller

17. Benefits: – Sale of excess energy to the grid – Lower system cost – Incentives supported Downfalls: – No battery back up. If the grid fails you are left in the dark.

18. Direct Drive Batteryless System Controller http://image.made-in-china.com/2f0j00seKTaQUBJEhy/Water-Pump-MKP60-1-.jpg

19. Benefits: – Simplicity – Lowest in cost (no balance of system needed) Downfalls: – Only power loads when resource is available – Heating applications require large turbines