There are basically two major area’s of information required to have an essential knowledge of domestic wind turbines. The first is understanding energy yield and energy consumption. The second is choosing which type of turbine wind generator best suites your needs and situation.
Understanding Energy Yeild and Energy Consumption A simple way of putting things is
- An average modern homes requires 4,500kWh. per year.
- A domestic wind turbine with a 5 meter rotar diameter provides 4000 – 4,500 kWh, per year in good wind conditions.
- A domestic wind turbine with a 2 meter rotar diameter provides 500 kWh, per year in good wind conditions.
Which type of Turbine Wind Generator? Lets begin with a quick overview of the different types of turbine wind generators available and some of the pros and cons with each.
Horizontal-axis wind turbines (HAWT)
These are far and away the most common type of domestic wind turbines. HAWT’s also have a long history, being the principle behind the famous Dutch Windmills. Advantages: An obvious key advantage is that they are easily available. In addition the blades of HAWT’s can be changed in pitch so as to more fully catch the wind. Secondly they are easiy mounted on high towers which maximizes their access to wind shear. Lastly HAWT’s have had the most research and development backing and use in the field. In simple terms at the low end they are easy to build and at the high end there is some pretty complex wind turbine management systems build in. Disadvantages: HAWT’s don’t operate well at ground level. All other disadvantage relate to large installation HAWT’s – such as difficulty with installation of the towers, signal clutter if installed near radar installations, and cost of shipping and the tower system. For use as domestic wind tubines we only recommend micro-HAWT installation. For micro-HAWT installation and how easy it is an advantage, details on easy building and installation of turbine wind generators can be found here.
Vertical-axis wind turbines (VAWT)
There are a few subcategories of (VAWT)’s.
They are:
- Darrieus (or eggbeater) wind turbine
- Giromill
- Savonius wind turbine
- “H” vertical wind turbine
Although many would argue long and hard about the various merits of each design (and the do have them) fundamentaly the advantages of VAWT’s are the same regardless of design.
Advantages: They can be built on the ground making installation and maintenance easier, they generate power at a lower RPM rate than HAWT’s , they integrate better into an urban environment and some claim they are quieter and easier for birds to avoid.
Disadvantages: They generally produce power at 50% of the efficency of HAWT’s. A great deal more stress is placed on the tower structure reducing relaibility and maintenance costs can be high. This is due to the whole structure being under it’s own weight, so to change a component at the bottom of the structure may require you to dismantle almost all of it.
Large vs Small Turbine Wind Generators
Both HAWT’s and VAWT’s com in large configurations. A very simple way of understanding the whole arguement regarding large and small turbine wind generators is to simple say “The larger they are the more efficently they generate electricity but the less flexible they are to manage.”. Almost all of advantages and disadvantages related to the size of a wind turbine fall into this area. Since we have already summed up our view on them, here are a few advantages and disadvantages that don;t fall under the above mentioned umbrella.
Advantages & Disadvantages: Large wind turbines have been blames for bird deaths, they cost much more to build and require much more approval than micro-wind. They are also much more noticable in the immediate environment. Small turbines are have more moving parts and are less efficent. However they are easy and cost effective to build at home and are more fleixble, being accessable enough to move or upgrade.
Basically electricity provided by micro-turbine wind generators will be more expensive on a per kWh. basis, however you will be in control and able to manage your supply and use of energy.
Building Integrated Wind Turbines.
Lastly a word on a recent innovation on integrating wind turbines. New plans are underway for the Bahrain World Trade Center to include wind turbines in its superstructure. These turbines will provide 11-15% of the buildings needs.
So if you build a new home in future, considering engaging an architect who can offer integrated wind turbines. Like with all alternative energy solutions, look into the return on investment (ROI). Will these integrated wind turbines pay for themselves in energy savings…? Will it take 2 years or 10?
However if you just want advice on how to best integrated you domestic wind turbines into your current housing structure then “Wind Energy Basics” is a good place to begin.
In Conclusion. Turbine wind generators come in many variations, with many advantages and disadvantages for each. The fact that domestic wind turbines are overwhelmingly HAWT configurations suggests they must be working. However a wind only approach to homemade electricity generation is not an effective strategy. Any attempt at energy independence must include multiple energy sources.
Dr Self Help
The most common are solar and wind. Excellent information on running your own successful energy independence project can be found here
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