Producing electricity from wind for on-site consumption is rapidly increasing in popularity for businesses looking to produce clean energy independently. Some companies have estimated that almost five percent of their customers are purchasing turbines for small businesses, schools, farms, ranches and municipalities. The number of restaurants, motels and gas stations generating wind power is growing, as well. Wal-Mart now has two stores with 15 turbines each installed in their parking lots (Worcester, Mass. and Palmdale, Calif.).
Requiring minimal upkeep, modern distributed wind turbines provide business owners with lower operational costs through energy savings, protection from future utility price increases as well as sending the visual message to customers that their business cares about the environment. What can business owners expect for ongoing operations and maintenance of installed wind turbines?
A small wind system is quite simple, consisting of three blades, which capture the kinetic energy of the wind; an alternator, which converts the wind into electricity; and the inverter, which converts the energy into useable household or alternating current. With only two moving parts, the rotor shaft bearing that holds the blades and the “yaw” bearing at the tower attachment that helps the turbine orient itself toward the wind source are permanently sealed and designed to last 20 years before replacement.
Periodic maintenance and regular safety inspections is all that is required and this can be done by the company’s network of independent dealers. In some cases the turbine will include a web-based remote monitoring system that will allow the owner, dealer or even the factory to monitor the performance and make any necessary adjustments if they occur. With proper installation and inspection, a turbine can last 20 years or more before it must be rebuilt
A factory certified installer can help ensure proper installation. The process takes only two days to complete – one to pour the tower foundation and one (up to28 days later) to install the tower and the turbine. The system should be installed in an area with average minimum wind speeds of 12 miles per hour and be sited at least 20 feet above any obstructions within a 250-foot radius. Depending on the site and installation complexity two to four installers may be needed. Proper installation will extend the system’s lifespan while decreasing the likelihood of future maintenance.
Safety and Troubleshooting
Small wind systems are designed to operate in aggressive environments and are built to withstand extreme daily conditions. All turbines have a maximum wind speed, called the survival speed, above which they will not operate. When winds over this maximum speed occur, a turbine’s speed control system will to prevent it from going faster than its survival speed. It’s important to check if the turbine has been certified by a reputable organization. The Small Wind Certification Corporation (SWCC) is the recognized organization within the U.S. that tests small wind systems. The international standard is called the IEC 61400-2. When comparing manufacturers, look for a certification.
The best way to compare wind generators is with the Energy curve, not the Power curve. The difference is; energy is the amount of work being done while power is the rate at which energy is being generated. When it comes to any renewable energy device, you first must understand the resource; for wind, that would be the wind speed average at the proposed site. There are numerous wind maps on the web that can help. Use the map to determine the annual average wind speed and compare it to the energy curve to get a “ball-park” estimate of what you would expect from the wind turbine. It is extremely important to note that there are numerous other factors that effect energy production. A few include; turbulence intensity, tower height, elevation and other environmental conditions. In many parts of the U.S., August is a low wind month. Spring and winter are normally windier seasons when a system may put out significantly more energy than in the summer. NABCEP (North American Board of Certified Energy Practitioners), has put introduced a new program on best practices for dealer siting and installation which will help consumer expectations. It is always a good idea to consult with a wind turbine dealer with experience in siting and installing a wind generator.
Written by Andy Kruse, Southwest Windpower
Andy Kruse oversees Southwest Windpower’s governmental affairs and certification efforts and is also responsible for developing long-term market strategies. Southwest Windpower is the world’s leading supplier of distributed wind generators, and with a history lasting more than two decades, the company is a global leader and pioneer in the design, manufacturing and distribution of small wind systems (400-3000 watts).