Small Scale Wind Turbine Georgianne Areizaga Haley Moore

Horizontal Axis Small Scale Wind Turbine Advantages Blades are to the side of the turbines center of gravity, helping stability Higher Power Coefficient Taller towers may be placed on uneven ground Little maintenance Improved angle of attack Challenges Efficiency of small size turbine is low Effect radar in proximity Aesthetics

What We Each Plan to Build Mechanical Design Components Rotor Tower Yawing Mechanism Gearbox Low speed shaft High speed shaft Braking mechanism Electrical Design Components Charge Controller Battery Bank VoltMeter Alternative Load Anemometer

What we will need to buy Generator Material for blades Electronic Components such as capacitors, instrumentation amplifiers Material for tower and hub Materials for gears and shaft If time is limited, we will buy the anemometer instead of designing. Generator - The generator will be our major purchase for this project.

Anemometer Blades Rotor Gear Box Generator Brake Charge Controller Battery Bank Dump Load Environment (wind) Voltmeter

Mechanical Design Rotor Tower Yawing Mechanism Gearbox -Gear Ratio Blade Material Tower Yawing Mechanism Gearbox -Gear Ratio -High Speed Shaft -Low Speed Shaft

Electrical Design Charge Controller Alternative Load Battery Bank To prevent continuous overcharging Alternative Load An alternative load where the energy can be safely handled Battery Bank An array of batteries charged by the solar panel Anemometer Device to measure wind speeds Voltmeter Device to measure DC voltage

Charge Controller Limits the rate that the current will be added or drawn from the battery bank The ideal solution is to use a charge controller that will charge the batteries fully and then switch to an alternative load, an alternative load. The charge controller constantly monitors the voltage of the battery bank.

Design Procedure of Charge Controller Two different charge controllers will be designed to compare efficiencies Design an electronic circuit Program microcontroller to mimic what an electronic circuit would do The charge controller will first be constructed on a breadboard. Once confirming functionality and efficiency, the designs will be constructed onto a printed circuit board.

Alternative Load Wind turbines are designed to be under a load A wind turbine is designed with a load because if it were to operate in a no load situation at high wind speeds, the turbine can be destroyed. Once the battery bank is fully charged, it is necessary that the wind turbine stop charging the battery bank as overcharging batteries is very bad. The ideal solution is to charge the batteries until they reach a full charge, then switch to an alternate load where the energy can be safely handled.

Battery Bank Affixing multiple batteries in series to increase the voltage. The battery bank will allow the turbine to charge more batteries and harness more of the energy that is being produced.

Voltmeter and Anemometer Voltmeter- A device that measures voltage Anemometer -A device that measures wind speeds Accurately display current voltage of battery bank and current wind speeds.

Efficiency Power Available in Wind (in Watts) ½ * air density * swept area * wind velocity3 Limit to power extracted by the wind (Betz Limit) Maximum power extraction = 59.26% Efficiency of conversion Coefficient of Power(Cp) =30% Betz --- More and more air tends to go around the turbine rather than through it, with air pooling up in front. Kemen --- Klemen averaged the efficiency of Power(Cp) if the turbine Source: http://www.green-trust.org/freebooks/wind1-1.pdf

Projected Efficiency At 8.9m/s speeds with a 2 meter diameter turbine Pavailable = 1380 Watts Pactual = 414Watts At 4.4m/s speeds with a 2 meter diameter turbine Pavailable = 172 Watts Pactual= 51 Watts

Goals and Testing A turbine with a diameter of 2 meters Generate enough energy to power a laptop Conversion coefficient power (Cp) = 30% Charge controller that effectively keeps the battery bank from overcharging and the wind turbine always under load. We plan to test our project in the UNH Wind Tunnel

Sources http://www.green-trust.org/freebooks/wind1-1.pdf https://sites.google.com/site/ddmcintosh2projects/ChargeController http://www.theinventory.orconhosting.net.nz/chargecontrol.htm http://www.mdpub.com/Wind_Turbine/index.html http://www.windynation.com/articles/charge-controller/wind-turbine-dump-and-diversion-loads- what-they-do-and-how-choose-right-s http://me1065.wikidot.com/types-of-wind-turbines-and-associated-advantages http://www.windstuff.org/calc/calc.php