Wind Turbine and Photo Voltaic FAQ
New England Tech’s Renewable Energy Systems
Wind Turbine FAQ
1. Why does the wind turbine stop spinning some days?
The turbine requires a minimum wind speed of 6.7 M.P.H. to spin the blades. If the wind speed is below that, the turbine will not spin. There are times the turbine may be stopped during windy periods for maintenance etc. The turbine will automatically stop spinning if the wind speeds exceed 56 M.P.H.
2. Why does it seem like the turbine changes the direction it is facing?
Because it does change according to wind direction. The New England Tech wind turbine is an upwind style of turbine. There is a wind vane mounted on the top of the turbine that will tell the controller to turn the turbine into the wind. There is a small motor inside the turbine that will move the nacelle into the wind.
3. What are the blades made out of?
The blades are made from a reinforced fiberglass. There are black to help with shedding possible ice buildup in the winter.
4. How tall is the turbine?
The center of the rotor hub is 121 feet off the ground. The blade diameter is 69 feet. The height of the turbine to the tip of the blades is 156 feet.
5. How much power will the turbine generate?
The turbine is designed to generate 100 Kilowatts at 34 M.P.H. winds. If the wind speed is less, the turbine will generate less power.
6. How much does the turbine weigh?
The entire system, tower, nacelle and blades weigh over 46,000 lbs!
7. Does anybody monitor the turbine?
Yes, the manufacturer, Northern Power monitors the turbine remotely for any problems that may arise. The turbine can be stopped remotely if there are any issues. The turbine also monitors itself and will report any problems to Northern Power and stop itself if necessary. New England Tech students will also be monitoring the turbine in the future.
8. What is the life span of the New England Tech turbine?
The turbine has a minimum life expectancy of 20 years.
9. What is the voltage the turbine produces?
The turbine is an Alternating Current (AC) generator which gets converted to Direct Current (DC) and is then converted back to utility quaility 480 volt Alternating Current by a device inside the turbine called an inverter the power is then ready for use in the New England Tech Automotive building.
10. Is the turbine connected to the Utility Power Grid?
Yes. If the turbine produces “extra power” that is not consumed by the automotive building, the power is returned to the utility grid and New England Tech will receive credits for the energy sold back.
Inside the NW100 Wind Turbine
Measures the wind speed and transmits wind speed data to the controller.
Most turbines have either two or three blades. Wind blowing over the blades causes the blades to "lift" and rotate.
A disc brake, which can be applied mechanically, electrically, or hydraulically to stop the rotor in emergencies.
The controller starts up the machine at wind speeds of about 8 to 16 miles per hour (mph) and shuts off the machine at about 55 mph. Turbines do not operate at wind speeds above about 55 mph because they might be damaged by the high winds.
Usually an off-the-shelf induction generator that produces 60-cycle AC electricity.
Used with turbines that have a DC generator. Converts the DC volts to required AC volts.
The rotor turns the low-speed shaft at about 30 to 60 rotations per minute.
The nacelle sits atop the tower and contains the gear box, low- and high-speed shafts, generator, controller, and brake. Some nacelles are large enough for a helicopter to land on.
The blades and the hub together are called the rotor.
Towers are made from tubular steel (shown here), concrete, or steel lattice. Because wind speed increases with height, taller towers enable turbines to capture more energy and generate more electricity.
This is an "upwind" turbine, so-called because it operates facing into the wind. Other turbines are designed to run "downwind," facing away from the wind.
Measures wind direction and communicates with the yaw drive to orient the turbine properly with respect to the wind.
Upwind turbines face into the wind; the yaw drive is used to keep the rotor facing into the wind as the wind direction changes. Downwind turbines don't require a yaw drive, the wind blows the rotor downwind.
Powers the yaw drive.
Photo Voltaic System FAQ
1. How many solar panels are there on the Electrical Technology building?
There are 135 panels, each capable of producing 175 watts, mounted on the roof.
2. How much power will the PV system produce?
The system is rated to produce 23 Kilowatts of power. That will vary with sun angles, cloud cover and time of day.
3. When was the PV installed?
The system went online on May 11th, 2009. It took approximately 3 weeks for the installation to be completed. The project took over one year from start to finish.
4. Is the system connected to the Utility Power Grid?
Yes, just like the wind turbine, any “extra power” is sold back to the utility.
5. How do the PV panels work?
Photo Voltaic energy has been in existence since the late 1800’s! Its original use was to power remote telegraph stations. The space program in the 1960’s used PV panels for all energy production in space. Things have changed drastically since then and the PV panels are much more efficient in energy production. A PV panel is a semiconductor material that when it is struck by light, the electrons in the semiconductor material are released. Moving electrons equals electricity! PV panels have no moving parts and are expected to last over 25 years.
6. What is the voltage for the PV system?
The panels are wired to provide 322 Direct Current Volts (DC). It is then converted, using an inverter like the wind turbine, to 208 Volts Alternating Current (AC) for use in the Electrical Technology building.
7. Does anybody monitor the PV system?
Yes, there is a system installed that monitors the system. The system also monitors itself and will shut down automatically if a problem should arise. The system has never been shut down since it was commissioned in May.