Harnessing the Wind s Energy. How It Works

Transcription

1 Harnessing the Wind s Energy How It Works

2 Anatomy of a Typical 1.5 MW Wind Turbine Turbine Weight: 480,500 lbs Tower: Tubular steel Tower Height: 255 ft 7 in Tower Diameter (base): 15 ft Tower Weight: 276,000 Ibs

3 The Blades Typical 1.5 MW Wind Turbine Blades Composite fiberglass Length: 135 Ft. Diameter: 6 Ft. Weight: 14,000 (each blade)

4 The Rotor Typical 1.5 MW Wind Turbine Rotor A rotor is composed of three blades and has a diameter of approximately 270 feet 25% longer than the wingspan of a Boeing jumbo jet.

5 The Hub Typical 1.5 MW Wind Turbine Hub Weight: 37,000 Ibs Diameter 10ft

6 The Nacelle Sits on top of the tower and houses the power train The nacelle is approximately 13 ft wide, 13 ft tall and 26 ft long.

7 Tracking the Wind A wind turbine continually tracks the wind through an on-board computer which monitors the wind direction sensor and an anemometer for measuring wind speed. Once the wind reaches (approximately 3.5m/s or 8 mph), known as cut in speed, the blades will pitch, to full power position, and the turbine will begin generating electricity. The nameplate rating of a modern turbine is typically between 1,500 kw and 3,000 kw. A typical 1.5 MW turbine annually produces enough electricity to meet the average annual demand of about 750 U.S. homes.

8 Understanding Wattage What is a megawatt (MW) and how many homes can one MW of generation really serve? Watts (W) are the yardstick for measuring power. A one hundred watt light bulb, for example, is rated to consume one hundred watts (or 0.1 KW) of power when turned on. If such a light bulb were on for four hours it would consume a total of 0.4 WKh of energy. Watts, therefore, measure instantaneous power while watt-hours measure the total amount of energy consumed over a period of time. A megawatt (MW) is one million watts and a kilowatt (kw) is one thousand watts. Residential Electricity Consumption Amount of electricity consumed by a typical residential household varies by region of the country, as well a other factors. According to 2001 Energy Information Administration (EIA) data, New England residential customers consume the least amount of electricity, averaging 650 kilowatt hours (kwh) per month per household, while the East South Central region, which includes states such as Georgia and Alabama and Tennessee, consumes nearly double that amount at almost 1,200 kwh per month per household.

9 Catching the Wind Wind turbine blades typically rotate between revolutions per minute (RPM), depending upon wind conditions. When the cut in wind speed is reached, the blades pitch to full power position. This then turns the gearbox through a mainshaft. The gearbox takes the rpm rotation from the hub/mainshaft and ramps it up to 1400 to 1800 rpm, depending on the turbine, as input to the generator.

10 Generating Power Once the generator speed is met, power flows from the generator to a step-up transformer typically at the base of each tower. The generator voltages range from 575 to 690 volts. The step up transformer increases the voltage to 34.5kv or 34,500 volts. The power then typically gets further stepped up in voltage at a substation and is then exported into the utility grid.

11 A Snapshot of the U.S. Wind farms are typically sited in regions that have annual average wind speed of at least miles per hour with proximity to existing high voltage transmission lines. Map of the Average Annual Wind Power The Electrical Grid

12 Environmental Benefits Wind power is environmentally sustainable. Wind turbines don t produce CO₂ emissions, so they do not contribute to climate change. Wind power helps preserve our finite supplies of fossil fuels. Wind power plants do not consume water Wind power is compatible with existing agricultural land uses Wind power is renewable because it is generated from daily solar radiation and cannot be depleted.

13 Glossary of Terms Anemometer Cut In Speed Electrical Grid Gearbox Generator Hub Main Shaft Nacelle Padmount Transformer Pitch Rotor Substation Tower Transmission Lines Turbine VAC Wind Vane Yaw Drive an instrument for measuring wind speed the lowest wind speed at which a wind turbine begins producing usable power an interconnected network for delivering electricity from power plants to consumers converts the slow, high-torque rotation of the rotor into much faster rotation for the electrical generator a device that converts mechanical energy to electrical energy, generally using electromagnetic induction the blades of the turbine are attached to the hub the rotor is bolted to a mainshaft which runs to the gearbox the structure that houses all of the power train and generating components mounted on the ground to step up the voltage the angle of the blades all blades attached to the hub a subsidiary station of an electricity generation, transmission and distribution system where voltage is transformed from high to low or the reverse using transformers the tower that supports the wind turbine nacelle the structure and circuits that transport electricity from one place to another. a rotary engine that extracts energy from a fluid flow Volts Alternating Current an instrument for measuring the wind direction a device used to keep the rotor facing into the wind as the wind direction changes