- What is wind energy?
- What is a wind turbine, and how does it make electricity?
- What is a kW and what is a kWh?
- Who is involved in this project?
- Why a wind turbine on UD’s Lewes campus?
- How big is the wind turbine?
- When was the turbine installed?
- How much electricity does the wind turbine generate?
- Do the blades spin at the same speed all the time?
- Why aren't the blades spinning right now?
- How does the cost of wind turbines compare with other forms of electricity generation?
- What are the long-term costs associated with operation and maintenance of a wind turbine?
- How much noise does a wind turbine make?
- What studies were conducted prior to turbine installation?
- What kind of research is being done on the turbine?
- I've heard about turbine failures. Is that a concern?
- What are the environmental impacts of a wind turbine?
Frequently Asked QuestionsMuch of the information on this page is taken from the web site of our partner, Sustainable Energy Developments Inc.
Wind energy is the energy contained in the movement of air. The sun heats the earth at different rates and times. The variance in temperature throughout the earth generates pressure disparities that in turn drive the movement of air. Air has mass and when a mass is put in motion it contains what is called kinetic energy, much like a baseball thrown by a pitcher.
Humans have used wind energy for centuries to drive pumps and mills by taking the kinetic energy and converting it to mechanical energy through the use of windmills. This same concept is used to convert kinetic energy into electrical energy through the use of wind turbines.
A wind turbine is a machine that harnesses the kinetic energy in the wind and converts it to electrical energy. Mechanical energy created by its rotating blades turns a generator that creates electricity. A typical wind turbine consists of the following features:
- Rotor Blades – rotate in response to the wind and are attached to the rotor hub
- Rotor Hub – connected to a gearbox and generator inside the nacelle
- Generator – converts mechanical energy into electricity
- Nacelle – houses the mechanical and electrical components of the turbine
- Tower – used to elevate the nacelle, hub, and blades so to reach greater wind
A kW (kilo-watt) is a rate of energy production or consumption, and a kWh (kilo-watt-hour) is a unit of energy. Think of it like driving in your car. Miles per hour is a rate at which you produce distance with your car and a mile is a unit of distance. For example if you drive for 1 hour at 60 miles per hour you have traveled a total of 60 miles. Similarly if you produce 60 kW of power for an hour you have produced a total of 60 kWh.
The joint venture, First State Marine Wind, is a partnership between University of Delaware-owned Blue Hen Wind and Gamesa USA. Other project partners include the City of Lewes and Sustainable Energy Developments Inc.
UD officials chose wind power to meet its commitment to reduce its carbon footprint due to the favorable winds in the coastal area of Lewes and also for the educational and research opportunities it presents.
One hundred percent of the campus' electricity is provided by wind power though this project, thus meeting all the campus' electricity needs with no net carbon emissions and making it a model for other institutions in the nation. At times, the turbine generates more than enough power for the campus; the excess is fed to the electric grid for use by others in Lewes.
In addition to providing carbon-free electricity, the project enhances research in areas such as turbine corrosion, avian impacts, and policy issues related to renewable energy. Information gained from the project is helping the university and Gamesa work toward establishing the first offshore wind turbine in the Americas.
The size of wind turbines varies and is directly related to their designed electrical output. The University of Delaware turbine is a 2-megawatt (2-MW) machine, which stands approximately 400 feet high from its tower base to the apex of its blade at peak rotation. Each of the turbine's three blades is approximately 140 feet long.
Construction began in March 2010; the turbine was fully operational three months later.
The amount of electricity produced by one turbine depends on its size and quality of wind resource. A typical 2-megawatt turbine, when placed in an appropriate wind resource, can provide enough emissions-free electricity to power about 500 average homes for a full year.
UD’s turbine generates varying amounts of energy throughout the year — there is more wind available for the turbine in Lewes during the winter than in the summer, for example. Regardless of such fluctuations, the turbine produces more than enough power to support the six buildings at the Lewes campus over the course of a year. Check back later in 2011, when a report will be available about the turbine’s performance over its first year.
While the blades do spin at variable speeds, the range of speeds is very limited. The blades turn anywhere from nine to 19 revolutions per minute.
There are three reasons why the blades might not be spinning: 1) There is not enough wind. The turbine is programmed to begin generating electricity when the hub-height wind speed reaches 8 miles per hour. 2) The turbine is in need of or undergoing maintenance. Like your car, the wind turbine undergoes regularly scheduled maintenance; at other times, unscheduled events occur that require turbine maintenance. For safety purposes, the blades are stopped when technicians work on the turbine. 3) For some research projects, such as the avian and bat study currently under way, technicians must climb the tower to mount a device.
Traditional fossil fuel-generated electricity requires consistent input of a fuel; typically oil, gas, or coal. These non-renewable resources must be located, extracted, transported, processed, burned, and the waste treated and removed. Each of these processes costs money throughout the life of the generating plant. Wind turbines simply use the force of the wind as fuel, and only require periodic maintenance. As fossil fuel resources decline and their costs increase, proven technologies such as wind energy have become an attractive long-term electricity solution. If we look at all forms of electricity generation stripped of the apparent and hidden subsidies, then wind power is competitive.
Like any large and complex machine, wind turbines require monitoring and periodic maintenance to keep them operational. Wind turbine vendors seldom warranty their machines for longer than 2 years, so it is important to have a plan for maintenance.
With advances in the engineering and manufacturing of wind turbines, the noise generated by wind turbines has been greatly reduced. Any noise generated is usually from the mechanical components, electric power conditioning, and the blades moving through the air. All modern wind turbine manufacturers design their wind turbines with particular attention to minimizing noise. Siting the turbine at an appropriate distance from occupied buildings also minimizes any potential disturbance from turbine noise.
Pre-construction and post-construction sound studies were undertaken with this project. The pre-construction study concluded that the sound from the wind turbine would be well below Delaware regulations, which limit absolute sound levels and sound levels in relation to background ambient sound. The post-construction study confirmed that the wind turbine complies with state law.
Prior to constructing its wind turbine in Lewes, the University of Delaware engaged experts to conduct several studies, including ones on avian and acoustic effects. UD also reviewed additional studies and reports, and held meetings in the community to identify potential concerns of nearby residents. UD also attended City Council and Lewes Board of Public Works meetings where the wind turbine was on the agenda and discussed. Visit our Background Documents page to learn more about the studies.
The UD wind turbine was created for research purposes, and several projects are taking place. A study on the turbine's effects on birds and bats is under way, and a corrosion study that will shed light on salt water's effect on sea-based wind turbines is taking place near the base of the wind turbine. Several other projects are getting off the ground, including one on the structural response of the turbine's tower to forces such as wind, and another on drive train wear of the gearbox. So far, studies on the turbine cross many disciplines and involve a microbiologist, ecologists, marine physicists, engineers, and marine policy specialists. Check our news page for the latest updates on projects.
Repairing wind turbines is very costly. Such efforts can require a crane and other expensive equipment in addition to the purchase of replacement parts. For that reason, wind turbines are designed to be very reliable, low-maintenance machines. While there are electrical or component failures of wind turbines, overall turbines are some of the most reliable machines available today. To ensure the UD wind turbine’s reliability, Gamesa is servicing the wind turbine under an operation and maintenance agreement. Two UD personnel have received maintenance training as well.
Although wind turbines do have an environmental cost, it is very minimal when compared to traditional sources of electricity. For example, a Danish study that looked at an offshore wind farm's effect on wildlife found an average of about three bird deaths per year per turbine. Birds tended to avoid the turbines by flying above, below, or around them, though the birds mostly flew around the whole wind farm. Such effects on the environment are relatively small when, for example, compared to oil spills that can kill birds and other animals, mountain mining of coal, air pollution from power plants that can harm both wildlife and humans, entrainment and mortality of fish by hydroelectric dams, and nuclear waste. Wind turbines do impact wildlife; however, and that is the reason UD scientists are trying to better understand a wind turbine's effect on birds and bats.