Renewable Wind Energy

Since ancient times, humans have been converting the kinetic energy of wind into mechanical energy. Today, wind turbines are gaining popularity as a means of producing all-purpose electrical energy. Natural wind causes the blades of a windmill to rotate, which then spin a magnet surrounded by a coil of wire. This spinning magnet surrounded by wire (a generator) creates electricity that we can use to power homes, businesses and cities. Although the basic process is exactly the same, innovative locations for wind farms, new blade/equipment technologies and advances in storage systems have modernized and are constantly enhancing the use of wind power making it an increasingly viable power source.

Community Associations must check their governing documents to see if there are site specific regulations directly prohibiting wind turbines and/or any association parameter that may bar the installation, such as aesthetic and noise ordinances. The economics must also be carefully calculated as small scale residential turbine technology is still in its infancy and may not be a viable alternative in all communities. Like any renewable energy, the initial cost is high (typical grid-connected home systems range from $3000 to $6000 per kilowatt) and the savings are extended over lengthy periods. Even if the small mill owner takes advantage of all available rebate/incentive programs and is in an area with strong to average wind speeds, the payback period may still be between ten and fifteen years. Nonetheless, wind is quickly gaining momentum as an alternative to fossil fuels.

Innovative Locations
In the past, wind farms were land-bound. Today, however, turbines are being erected inland, offshore and even on city buildings. Land-bound wind farms are located on flat plains and in mountainous regions, but where exactly they are installed is a science in it of itself. Because a difference of just 30 meters can a double the output of an apparatus, engineers have and continue to develop better ways of micro-siting, scientifically calculating the ideal location, height and positioning of windmills.

In addition to inland wind farms, offshore turbines are now feasible and increasingly economical. Firstly, offshore wind turbines are less obtrusive than inland wind farms, as their apparent size and noise is mitigated by distance. In addition, offshore wind farms can produce more electricity because wind blows harder and more consistently over water. Also, because ships and barges can handle large loads more easily than trucks or trains, transporting large wind turbine components is much easier and cheaper over water than on land. The major restriction on offshore wind farms is the requirement to run power cables along the ocean floor to connect the produced electrical energy with the power grid.

In the future, micro-turbines may be popping up on the rooftops of urban high rise buildings. In Portland, four experimental 45-foot-tall wind turbines on top of the Twelve West Building produce about one percent of the building's electricity needs each year and serve as a learning example for turbine technicians. In Chicago, Dr. Bill Becker is developing a double-helix wind turbine specifically for urban settings. The propellers of his Aeroturbine resemble an electric beater and are contained in a metal cage so that the system can easily be installed onto existing high rise buildings in a vertical, horizontal or diagonal orientation.

New Technologies for Higher Efficiency
Breaking ground with new locations for wind farms, engineers are also pioneering new technologies to increase turbine efficiency. Some scientists are revisiting the advantages of twin-blade turbines. Others believe that bigger is better and are designing the world's largest turbine. Since installing seabed foundations for offshore machines is so difficult and costly, floating platforms are currently being considered and tested.

One major technological progression is the implementation of variable pitch blades. Optimizing blade pitch and adjusting for changes in air density or blade contamination, variable pitch turbines produce more energy than fixed pitch or non-adjustable turbines. Likewise, a turning hub allows the rotors to be adjusted both along the lateral axis (pitch) and the vertical axis (yaw) to optimize the amount of wind captured. Working to improve this technology, USA-based BroadStar Wind Systems has created the AeroCam wind turbine, whose paddle-like rotor blades alter themselves continuously according to where they are in the 360 degree rotational cycle. At the top, the blades are horizontally positioned to capture maximum "wing" lift and rotation. Retreating blades are vertically positioned to create downwind sails that also contribute to the turning effect.

Improved Storage Technologies
One problem with using wind as a means of producing large quantities of electricity is that the turbines are most often located far from the electrical grid and far from where the electricity is needed. Another problem is that wind often produces the most power at times when the demand is low. The solution to both of these issues is to store the power. Today, storing electricity is more expensive than generating it. In the future, however, through advances in technologies such as flow batteries and compressed air, wind energy may become a more cost-attractive alternative to fossil fuels.

Flow batteries store energy in charged electrolytes and utilize proton exchange membranes similar to fuel cells. By flowing the (charged or uncharged) electrolytes through the cell, chemical energy is directly converted to electricity. Flow batteries are rather complicated as they require pumps, sensors, control units and secondary containment vessels. Nonetheless, constant research is aimed at enhancing flow battery capabilities.

Compressed air energy storage (CAES) is a method of storing energy within pressurized air held in underground chambers. These storage systems generate energy when demand is low (off-peak hours typically at night) for use at times when demand peaks. Because compressing air produces heat and expanding air is cooled, heat exchangers are used to avoid excessively high or low temperatures. These thermodynamic considerations and maintaining high efficiency over a wide range of pressures are the technical challenges engineers are currently working to overcome.

Change of Public Opinion
In the 1970s, there were oil shortages which made many people realize that fossil fuels will not last forever. Recent concern about global warming has made people more conscious of the need for clean and renewable resources. Wind is clean and free. Nonetheless, debate surrounds the issue of wind farms in regards to wildlife, aesthesis and noise pollution.

One fault found with wind farms is the fact that the massive fiberglass blades can kill migrating birds and other wildlife flying in their path. Environmentalists estimate that nearly 5,000 birds, including golden eagles, red-tailed hawks and burrowing owls, are killed annually by the windmills sited in the Diablo Mountains of California. Many dismiss this concern as twice as many birds are killed by cars and trucks each year.

Another criticism is that windmills cause visual pollution. In Cape Cod, local groups have been fighting the proposed 130 turbine project since 2001 saying that it would be an eyesore destroying the pristine views. The same argument has stalled plans to erect offshore turbines near Ocean City, New Jersey. While some find windmills to be unsightly, others perceive them as beautiful and relaxing in part because of their ecological rationality.

Like opinions about aesthetic appearances, noise issues are in the eye of the beholder. Although some find the noise irritating, others find the soft swoosh of the blades soothing and peaceful. Either way, engineers have largely eliminated the issue of noise by changing the thickness of the blades' trailing edges and by making machines "upwind" rather than "downwind." Distance setbacks also minimize the noise. Today, a turbine 300 meters away can be no louder than the reading room of a library.

With innovative locations for wind farms, new blade/equipment technologies and advances in storage systems, wind is quickly gaining momentum as an alternative to fossil fuels. In fact, the U.S. Department of Energy (DOE) is working to achieve 20% wind power in the United States by 2030.

Wind Power for Community Associations
Community Associations can jump on this green bandwagon, without turning backyards into wind farms, by purchasing wind produced energy. As individual states deregulate electricity, consumers have the opportunity to choose where they buy their power, just as they can choose their long-distance phone company. In short, Community Associations can power their common areas (clubhouses, common hallways, street lights and the likes) with wind produced electricity sold by a third party producer and delivered as always by the local utility company. In many cases green energy is cheaper than the electricity sold by the utility itself. Because deregulation has created a competitive marketplace, driving prices down and quality up, associations and individual unit owners have the opportunity to choose their supplier and save money each month.

Overall, engineers are constantly working to improve both large and small scale turbine systems and you can be sure that you will hear a lot more about wind power in the future.