Micro Wind Turbine: Things You Should Know About
Are you tired of paying high utility bills? Are you eager to be self sufficient where electricity is concerned and not rely on the electrical grid? Wind energy is one of the best alternatives you can find.
For a home or a small community or a small business, you don’t need to have the large wind turbines – and they are too expensive anyway. What you actually need is a micro wind turbine.
These can be pretty small and lightweight and you can even install one on your roof like a TV aerial, although rooftop installations are not very ideal.
Let us tell you everything you need to know about micro wind turbines.
What is a Micro Wind Turbine?
Micro wind turbines are small wind turbines used for microgeneration. That means they are used to generate electric power on the small scale to meet the needs of individuals and small businesses or communities.
Micro wind turbines differ from large commercial wind turbines like the ones you find in wind firms in that they have far less individual power output. Micro wind turbines are more ideal for residential energy production.
According to the Canadian Wind Energy Association (CanWEA), a small wind turbine ranges between less than 1000 watts (1 kW) and 300 kW. Really small ones can be as small as a 50-Watt auxiliary power generator used to power a miniature refrigeration unit, a caravan, or a boat.
According to the IEC-61400-2:2006 standard, a small wind turbine is one whose rotor-swept area is less than 200 square meters and which generates energy at a voltage less than 1000 Va.c. ir 1500 Vd.c.
The Design of Micro Wind Turbines
Micro wind turbines for residential use typically have blades with a diameter of 1.5 to 3.5 meters (4 ft 11 in to 11 ft 6 in). They produce between 1 and 10 kW of electricity when operating at an optimal wind speed.
Some micro wind turbines are rather lightweight – weighing as low as 16 kg (35 lb). The light weight gives the turbine sensitivity to minor wind movements or wind gusts, which is what you commonly get in urban areas. It also makes the turbine easy to mount, almost like a television antenna.
There are two types of wind turbines:
Most small wind turbines are horizontal-axis turbines. However, the demand for vertical-axis turbines is increasing in the small wind turbine market, and makers of vertical-axis turbines (WePower, Helix Wind etc) have reported an increase in sales.
Micro wind turbines typically use three-phase alternating current generators, with the trend being to use an induction generator. Induction generators are commonly used in wind turbines as well as some micro hydro installations because they are able to produce useful power at varying rotor speeds.
These generators are electrically as well as mechanically simpler than other types of generators. Furthermore, they are more rugged and do not require any brushes or commutators.
However, some small wind turbines operate with single-phase generators.
Some are designed to operate even at low wind speeds. However, micro wind turbines typically need a minimum wind speed of 4 meters per second (13 ft/s).
They employ dynamic braking, which enables them to control the speed by dumping excess energy to ensure the turbine is able to keep producing electricity even in high winds.
You can install the dynamic braking resistor inside the building so as to provide heat. This is useful in during high winds, as the building loses more heat while the braking resistor produces more heat.
Micro wind turbines usually feature direct current output, direct drive generators, lifetime bearings, and have a vane to point into the wind.
Permits and Approvals Before Installation
Before you can commence micro-wind generation, there are permits and approvals you have to acquire. They are the consistent with the permits and approvals required for other forms of microgeneration.
They are typically acquired from the organization of the judiciary which is responsible for electrical utilities.
You acquire the permits and approvals before you install. The process of securing the relevant permits and zoning is a necessary step in all energy projects.
Note, however, that the processes and information needed to acquire permits for wind projects is different for different geographical areas.
You may also have to seek for the permits at multiple levels: local, federal, and national. There are federal, state, and local regulations in place that govern various aspects of wind energy development. The level/amount of regulation required will depend on the nature or location of the project. For instance, in some locations, installations of wind turbines are required to comply with air navigation or aeronautical safety.
Wind Energy Ordinances are the tools used to regulate various aspects of wind projects – for instance, permitting process, location and construction. These ordinances give clarity to wind developers and to the public.
Installing a Micro Wind Turbine
The installation of a micro-wind turbine comprises typically comprises these two things: the turbine and an inverter.
The turbine has blades that spin due to the force of the wind. The rotation of the blades generates mechanical energy. This energy gets converted to direct current (DC). The inverter takes the direct current and converts it into alternating current (AC).
The output of the inverter is connected to a breaker panel which enables sharing of the electricity amongst the electric equipment in your home.
If there is excess electricity generated, there is a bidirectional meter which enables exporting of the surplus electricity to the electrical grid. For doing this, you are supplied with credits by the retailer.
Wind turbines are usually mounted on a tower, so as to ensure they are above any nearby obstacles. The rule of thumb is to install at least 9 m (30 ft) higher than anything within 150 m (490 ft). The best location for installing a wind turbine is far away from any large upwind obstacles, to ensure the path of the wind is unobstructed.
You can install your micro wind turbine on the roof of your house. In this case, the installation issues to keep in mind will include your roof’s strength, vibration, and roof ledge-caused turbulence.
Note that small-scale rooftop turbines are prone to turbulence, and as a result are not likely to produce significant amounts of power. This is particularly true in urban areas.
We hope this article has convinced you that micro wind turbines are a practical solution to your electricity problems. If you live in an area that gets plenty of wind, why don’t you utilize that natural resource and reduce your cost of living or doing business.
Besides, if you are a solar energy enthusiast, a wind turbine is one of the best ways to keep off-grid in the winter months.