Many people who live in a windy climate are considering the addition of a windmill energy turbine as their renewable energy source. The incentives to do so are numerous and effective.
Wind Electricity Basics
Small wind-electric systems can provide electricity on remote, off-grid home sites or right in a community setting connected to the utility grid. Although wind systems may require some maintenance and attention than solar-electric or micro-hydro-electric systems it could be the right choice for your family. Investing in quality equipment, good design and proper installation, wind electric systems do make economic and environmental sense. Your own windmill energy system will bring you and your family a great deal of satisfaction. There is nothing quite like watching your wind generator convert a summer breeze or a winter storm into electrical energy.
How It Works
The concept is quite basic. A wind generator’s rotating blades convert the kinetic energy of the wind into rotational momentum in a shaft. The rotating shaft turns an alternator, which then makes electricity. This electricity is transmitted through wiring down the tower to its end use in your home 81Aircon.
The blades of a windmill use engineered airfoils, matched to the alternator, that capture the energy of the wind. Most modern wind generators use three blades, the best compromise between the highest efficiency possible (one blade) and the balance that comes with multiple blades. Together, the blades and the hub they are attached to are termed the rotor, which is the collector of the system, intercepting winds that pass by. Most turbines on the market today are upwind machines-their blades are on the windward side of the tower. A few downwind machines are available, but neither configuration has a clear performance advantage over the other.
In most small-scale designs, the rotor is connected directly to the shaft of a permanent magnet alternator, which creates wild, three-phase AC. Wild, three-phase electricity means that the voltage and frequency vary continuously with the wind speed. They are not fixed like the 60 Hz, 120 VAC electricity coming out of common household outlets. The wild output is rectified to DC to either charge batteries or feed a grid-synchronous inverter. In most designs (up to 15 KW in peak capacity), the rotor is usually connected directly to the alternator, which eliminates the additional maintenance of gears. In systems 20 KW and larger, as well as some smaller wind systems (like the Endurance, Tulipo, or Aircon), a gearbox is used to increase alternator speed from a slower turning rotor.
The blades must turn to face the wind, so a yaw bearing is needed, allowing the wind turbine to track the winds as they shift direction. The tail directs the rotor into the wind. Some sort of governing system limits the rotor rpm as well as generator output to protect the turbine from high winds. A shutdown mechanism is also useful to stop the machine when necessary, such as during an extreme storm, when you do not need the energy, or when you want to service the system.
How To Choose A Wind Turbine
Trying to keep an inexpensive wind generator running can be an uphill battle that you will soon tire of. You can expect to pay more for a quality machine-it’s a difficult job to design and manufacture a long-lasting, small-scale wind generator.
Buy a turbine that has a good track record and a good warranty. Five years is preferable but may not always be available in the small wind turbine industry. A warranty is one indication of the manufacturer’s confidence in their product and their intention to stand behind it.
Real-world reports from users carry even more weight than a warranty, so search for people who own the model of turbine you are considering buying and get the straight scoop from them about performance, durability, reliability, and maintenance issues.
Note that a number of the wind turbines listed here are relatively new introductions with not very much customer run-time in North America. These turbines include the ARE, Eoltec, Kestrel, and Skystream. We recommend that you contact either your local wind turbine installer, or the manufacturers or importers and find out how many of these machines are actually operating in North America. Then contact the owners, and inquire about their experience and satisfaction with both the machine and the manufacturer or importer.
Some manufacturers make only battery-charging machines, and may offer a variety of turbine voltages. Others produce machines intended to connect to grid-synchronous inverters without batteries. One machine even includes an inverter integrated with the turbine itself. Make sure you are buying a machine that is appropriate for your intended use. Research will be key.