Photos of Northern Power Systems

Northern Power Systems is one of the pioneering wind companies in the USA. They were remanufacturing used Jacobs generators from the 1930s when I joined the industry in the mid 1970s.

Named for their Vermont location, one of the most northern states in the US, the company has gone through several iterations. Today the name harkens back to its beginnings in the 1970s.

Initially the company rebuilt used turbines and then gradually moved into building special-purpose wind turbines, mostly for the remote market—their niche.

For many years Northern Power’s chief designer was Clint (Jito) Coleman. His designs were always noteworthy, if not always successful.

One of Northern Power’s most long-lived products—and its most reliable—was the HR3. The HR in its designation was for High Reliability and it lived up to its billing.

Less successful was the firm’s experimentation with aileron controls—flaps—to limit power and protect the turbine from overspeed.

For the past decade, Northern Power has developed the NPS 100, a 21-meter, direct-drive wind turbine.


The HR3 was designed for remote, battery-charging applications. The HR in its designation was for High Reliability and it lived up to its billing.

In 1981 Art and Maxine Cook installed a 3 kW wind turbine on their farm in western Pennsylvania’s Somerset County. For nearly three decades Northern Power Systems’ HR3 had sat atop a 60-foot (18 m) truss tower on the Cooks’ lawn, reliably producing wind-generated electricity through winter snows and summer sun.

In high winds Northern Power Systems furls its HR3 model by tilting the rotor skyward, following the example of 1930s-era windcharger Parris-Dunn. A shock absorber dampens the rate at which the rotor returns to the running position. The design includes a winch and cable for manually furling the turbine.

One noteworthy HR3 operated for 12 hours in the furled position during a fierce Antarctic storm. The radio station eventually went off the air when the exhaust stack for the backup generator blew away. After the worst of the storm had passed, the HR3 dropped back into its running position, recharged the system’s batteries, and brought the station back to life. Twice during the first two years of operation anemometers at the site blew away, once after recording a wind speed of 126 mph (56 m/s).

NPS 100

Developed with a government grant, the NPS 100 was designed for remote sites, such as Alaskan villages.

The 21-meter diameter NPS 100 features a direct-drive, permanent-magnet alternator.

Several have been installed in single-turbine installations in the US and Canada and the company has begun selling the turbines in Europe, especially Great Britain.

Like Southwest Windpower’s far smaller Skystream, the NPS 100 has no aerodynamic means to protect the rotor. To protect the rotor from overspeed, the NPS 100 uses dynamic braking of the permanent magnet alternator.