Most small wind turbines today are rooted in the past. Eoltec did not look back when it came time to design the Scirocco, instead they took modern,  large, industrial wind turbines as an example, and scaled down what worked for the Scirocco. It has therefore more in common with large turbines than with other small wind turbines, such as blade-angle control instead of the commonly used furling for small wind generators.

Fixed width, fixed pitch-angle blades, such as the "pulltruded" ones found on a Bergey Excel, are cheap to make. They are however not very efficient, being a compromise to what already is a compromise at best. The apparent wind speed and angle at the root of a turbine blade is very different from that at the tip, where the blade moves through the air much faster. Proper blades are wider at their base, narrower at the tip, while the blade-angle, or pitch, also varies along its length. This is what you will find on the Scirocco, resulting in a much more efficient airfoil. The table below compares the percentage of power the Scirocco and Bergey Excel-S are able to extract from the available kinetic energy in the wind. These numbers may not seem all that impressive, keep in mind though that most small wind turbines generally have overall efficiencies of around 20%. There is also the theoretical efficiency limit for any wind turbine (called the Betz Limit) of 59%.

Thanks to its superior efficiency a Scirocco wind turbine will produce nearly as much  energy as the much larger Excel wind turbine. Pine Ridge Products in Montana, has been flying a Scirocco right next to an Excel, on separate towers at the exact same height, and confirms the Scirocco produces 87% of the electrical power of an Excel! This was measured over a 1 ½ year period, under real-world conditions.

The Scirocco was designed according to the IEC 61400-1 and IEC61400-2 design rules for wind turbines. Survival wind speed is 215 km/h (135 mph)! Unlike most small wind turbines, it does not use furling nor a diversion load to protect itself from overspeed. Instead, it has a fully-sealed centrifugal regulator that controls the pitch-angle of the blades so they stall in strong winds, limiting the blades to 245 rpm at any wind speed, even if the rotor is not loaded. Running unloaded means certain death for many other small wind turbines, even at low wind speeds. Thanks to pitch-control the Scirocco has a fail-safe design where uncontrolled rotor runaway cannot occur. It does not need a diversion load, and it will produce full output power from it's rated wind speed of 11.5 m/s (40 km/h, 25 mph) all the way through survival wind speed. Other wind turbines, such as the Bergey Excel, use furling to protect themselves, and their power production drops off rapidly once furling starts. They also get noisy when furled because of the turbulent airflow hitting the generator sideways. The Excel also suffers from inverter shutdown because the rotor overspeeds in high winds, causing overvoltage into the inverter. The Scirocco will produce its rated power of 6kW at any wind speed over 11.5 m/s (25 mph), and the inverter will never shut down at any windspeed!

Slow-speed, direct drive alternators are expensive! That is why most small wind turbines turn at high rotational rates. The other side of that equation is noise. The faster the turbine spins, the more noisy it tends to be. Typical rotation rates are 500 rpm for the SouthWest Windpower Whisper 500, and 310 rpm for the Bergey Excel. Compare that to a maximum of 245 rpm for the Scirocco! Another measure directly related to noise is blade tip speed. For a Whisper 500 it is an unbelievable 430 km/h (267 mph!!) when turning at 500 rpm. An Excel's rotor tips fly at 390 km/h (242 mph) at 310 rpm. The Scirocco clocks in at a tip speed of 260 km/h (161 mph) at 245 rpm. No wind turbine is silent, any manufacturer trying to claim so is selling snake oil. There are however large differences in the amount of noise produced by various wind turbines, and thanks to its lower tip speed the Scirocco is definitely at the quieter end of that spectrum. In fact, at most wind speeds the turbine sound will be masked by the sound of the wind and disappear in the background.

All of the above can be found in the comparison matrix as well. This compares a few of the popular wind turbines with the Eoltec Scirocco.

Eoltec is so sure the Scirocco will last a long time that they give a 5 year warranty. Sciroccos are flying in the harsh climates of Orkney (extreme winds!) and Canada (cold!), holding up great in these real-world tests.