Background

This turbine builds on twenty years of research and development at the University of Newcastle in Australia. This work includes field testing of three prototype wind turbines, two of these being 5 kW turbines which were the forerunners of the Aerogenesis turbine. The research work has included finite element modeling of the blade structure to ensure adequate strength, fatigue testing of blades, detailed computational modeling of the blade aerodynamics for optimum efficiency, excellent low wind performance and low noise.

Finite element modeling to determine the stresses in a 5 kW wind turbine blade

Fatigue Testing of an advanced 5 kW blade prototype

The Blades

The Aerogenesis 5 kW wind turbine is the new standard in small wind turbines. It embodies two fundamental principles: the use of leading edge technology and a maximum of standard, reliable, but cheap components. The technology starts with Aerogenesis's unique ability to design blades for optimal low wind and starting performance as well as efficient power extraction and low noise. The complex three-dimensional blade was designed using sophisticated computer optimization software and has been patented. Master moulds for the blades were machined on a computer controlled milling machine to ensure maximum dimensional accuracy. The blades are made by an advanced vacuum infusion method to ensure strength and a fatigue life of over 20 years.

Machining of blade mould

Connecting blade to blade carrier

The Generator

The heart of the turbine is the very rugged gearmotor. This unit consists of a gearbox, an induction generator, and an electrically powered disk brake for failsafe overspeed protection, parking the turbine if no power is required, and for keeping the blades stationary in high winds - up to 180 km/h. The gearmotor is mass produced to very high quality levels and very low cost and the saving, when compared to the permanent magnet generators used for most small turbines, is passed on to the turbine purchaser.

The Gearmotor

The Controller and Inverter

Possibly the most exciting technology in this turbine is the controller and Aerogenesis were quick to patent it when we realized how good it is. Based on the philosophy of maximizing the use of standard components we designed the controller on the basis of a standard motor speed controller, sometimes called an inverter, but our controller does much more than that. The three phase power generated by the turbine varies in frequency as the blade speed changes to match the wind speed. It is immediately rectified to a constant voltage and then inverted to produce 220 V, 50 Hz AC single phase output voltage whatever the wind speed. This process is controlled by a sophisticated microprocessor that also tracks the maximum power producing characteristic of the blades for most operating conditions but then deliberately slows down the blades at high wind speeds to avoid excessive power. This is the primary method of overspeed protection. Thus the disk brake at the rear of the gearmotor is the second level of overspeed protection, giving an overall degree of safety unmatched by any competitor.

In designing this turbine we have deliberately avoided using a furling tail fin, which is the common method of overspeed protection for small turbines. A furling tailfin collapses at high wind speed and turns the blades out of the wind. However, research at the University of Newcastle has shown that furling is associated with very high gyroscopic moments on the turbine shaft, and is, therefore, potentially dangerous. Another alternative is to mount the blades downwind of the tower but this causes "tower shadow" fatigue and other loads on the blades.

The Tower

The basic philosophy of the turbine design was also applied to the tower. If your site is accessible by a crane, then it is easy to install the 18 m tower as shown in the photo. The tower is a counterweighted swing tower hinged at 8 m from the base. The turbine side is slightly heavier than the counterweighted side. This allows the turbine to be raised and lowered by only a few people - fewer people are needed than shown in the photo. This makes the installation of the turbine and the yearly maintenance inspection very easy.

If you have a remote site that cannot be reached by a crane, an alternative "tilt-up" tower is also available. In its standard form, this tower comes in three 6 m lengths which are assembled on site and fitted to a 6 m long gin pole. This tower tilts up from its base using a cable passing over the gin pole and pulled either by a hand winch or a tractor or four wheel drive vehicle. When upright the tower is bolted to its base plate. If the site is very remote and transport is difficult, the tower can be specially made in more than three sections (at extra cost) to reduce the weight of the individual components. A 24 m tit-up tower is also available.

Most small turbine towers use guy wires for support, but these require considerable footings additional to that for the tower itself. The Aerogenesis tower is easier and cheaper to install.

Erecting the 18 m tower using a crane

Installing Your Turbine

The Aerogenesis 5 kW turbine on its standard 18 m tower will produce between 20 and 30 kilowatt-hours (kWhrs) per day at most sites. It is ideal for many remote power systems as well as direct grid connection where excess power can be fed back into the grid to make your electricity meter run backwards.

To determine the size of a remote power system, you must first estimate the number of kWhrs per day you will need, on average. If you have trouble doing this, contact us for a simple checklist that will help you work out the load. Any information you have about the local wind conditions, and the specifics of the site, can also be considered.

There are a few basic rules to keep in mind when selecting a site for your turbine. The high voltage of the generator means that the turbine can be placed at a considerable distance from the load with few line losses, but we recommend a distance no further than 500 m, partly to reduce the cost of cabling. The turbine should be clear of trees or buildings higher than about 10 m, at least in the direction of the prevailing winds. The site should be as flat as possible in the direction of the tower swing. High ground is preferred.

If you are building a remote power system, then you must decide the number of batteries as well as other power sources. A good rule-of-thumb is to provide enough batteries for three days of power when there is no wind, but you may wish to have more if it is essential that the power is always available. Alternatively a small back-up generator may be worthwhile. You should also consider integrating the wind turbine with other power sources, such as photovoltaic cells, as there are usually enough sunny but windless days, and vice versa, for the two sources to be complementary. Further advice on these matters is available by contacting us.

There is no standard voltage for remote power systems and many different voltages are used. 48 Volts (V) is probably the most common but up to 110 V is used. Generally, the higher the voltage, the cheaper the DC-DC link between the controller and the batteries. This is because the current rating (which largely determines cost) increases with decreasing voltage. Check with us for further advice on any of these matters.

Specifications

Eight Reasons to Buy the Aerogenesis 5 kW Turbine

1. Cheap and reliable
2. High efficiency state-of-the-art patented blades
3. Excellent low wind performance
4. Low noise
5. Easy grid connection
6. Patented controller is also inverter - no need to buy a separate inverter
7. Choice of unique towers for easy erection
8. Turbine is easily lowered for maintenance and safety in high winds