Southwest Windpower was begun by two young (at the time they seemed young to us) entrepreneurs: Dave Calley and Andy Kruse. Calley was the experimenter, and designer; Kruse, the marketing director.

Both had been in the business earlier with a micro wind turbine. Control of the turbine was wrested from them in a messy as well as murky process in the 1990s.

The two resurfaced years later as Southwest Windpower in Flagstaff, Arizona where they introduced the “Air” brand of micro wind turbine.

Subsequently, Southwest Windpower bought the rights to the Whisper line of mini wind turbines from Elliott Bayly at World Power Technologies in Duluth Minnesota.

In the mid 2000s Southwest Windpower developed a downwind, permanent-magnet, direct-drive wind turbine the Skystream. In doing so, the company moved from a micro turbine to a household-size wind turbine much larger than their previous machines.

Calley was known for his creative designs that lent themselves to the marketing of “sexy” products. The Air had a sweeping fish-like shape that’s been widely imitated. He followed that with the scimitar-like blades on the Skystream design. These design characteristics made Southwest Windpower turbines easily identifiable in the field.

By the time the company locked its doors in 2012, they had sold 8,000 of the Skystream product.

Air Microturbine

For its initial product, Southwest Windpower brought to market a highly-hyped micro turbine the “Air”. When introduced, the one-meter diameter Air was rated at 400 W.

The turbine—and its marketing—was controversial. Failures and complaints were high. The turbine was extremely noisy. Some compared it to a chain saw or a Harley Davidson motorcycle revving its engine.

The Air model went through many iterations. Most were simply numbered with the production series, but there were “major” revisions that resulted in new brand names such as the “Air X”, and eventually the “Air Breeze”.

The Breeze was rated at 200 W. This a major reduction in the official rated power of the turbine. However, at long last the turbine was both reliable and quiet. At the Wulf Field in the Tehachapi Pass, the turbine could consistently deliver nearly 150 W at its rated wind speed. The unit at the Wulf Field has operated consistently and reliable since installation in 2007.

• Air 403 Noise Measurements
• Air X ASU Power Curve
• Brazilian Tests Confirm Air 403 Underperforms Power Curve
• Testing the Power Curves of Small Wind Turbines

Whisper Wind Turbine

Whisper was a line of mini wind turbines developed by Elliott Bayly’s World Power Technologies in Duluth, Minnesota. He sold the line to Southwest Windpower sometime in the early 2000s.

The Whisper H40 was the most advanced of the series developed by Bayly. It used a carbon fiber rotor 7 feet (2.1 meters) in diameter and swept near 40 square feet (3.6 square meters)—the reason for the designation H40.

The turbine was “rated” at 900 W, though during tests at the Wulf Field in the Tehachapi Pass, the turbine never delivered its rated power at its rated wind speed.

The Whisper H40 was inexpensive and, thus, a popular choice for battery-charging applications. It was relatively quiet.

The turbine tested at the Wulf Field performed reliably for five years before it failed.

• Whisper H40 ASU Power Curve
• Whisper H40 Final Report

Skystream Wind Turbine

The Skystream was the last of the turbines developed by Southwest Windpower and one of the more recent introductions of new small wind turbine technology into the North American market.

As with the introduction of the Air turbine earlier, the Skystream was marketed heavily—some would say overhyped.

Nevertheless, Southwest Windpower courageously opted for a relatively low power rating of the 3.7 meter diameter downwind turbine. Initially the company rated the turbine at 1.8 kW. Moreover, unlike many small turbine manufacturer’s the marketing literature emphasize the 3.7 meter rotor in the marketing materials, and not the power rating. Thus, it was the Skystream 3.7 and not the 2 kW Skysteam.

Later Southwest Windpower succumbed to the exigencies of pressure on sales and “rerated” the turbine to 2.2 kW.

Though the Skystream did not have any aerodynamic means of overspeed protection—it depended on the dynamic breaking of its permanent-magnet generator—there are very few reports of catastrophic failures.

When the company locked its doors in 2012, Southwest Windpower had shipped 8,000 Skystream turbines.

• Skystream Delivers Less Than Advertised at French Test Site
• Commentary on the Skystream 3.7
• Skystream Field Observations
• New Federal Subsidies Distort the US Small Wind Market