Document Actions
WHI's Turbines
Wind Harvest International’s turbine models operate in the same basic manner as all blade-type vertical axis wind turbines (VAWTs). Wind moving over the blades creates lift and torque similar to blades of horizontal axis wind turbines (HAWTs). VAWTs have more drag than HAWTs because the blades revolve back into the wind. Because of this VAWTs aren’t generally as efficient at extracting energy out of the wind as HAWTs. WHI has solved this classic VAWT problem in two ways.
Model 1066
In 1992 Bob Thomas designed the Model 1066 turbine with a rated power of 50 kW. The turbine used 30 foot long blades of pultruded fiberglass. The turbine's rotor was 35.5 feet wide. Field testing demonstrated increased efficiency of the longer blades of that model and pointed to the potential to produce a cost-effective and efficient machine that does not employ "stators" (aerodynamically shaped columns on the outside superstructure that shape and funnel a wider swept area of wind into the rotors to increase power output). Read more... |
Model 530G
In 2001 and 2002 Wind Harvest installed three guyed wire supported
versions of the Model 530. Each rotor passes with 20 inches of its
neighbor. The close spacing produces the "coupled vortex" effect that
increases output of the interior turbines by 75% in 16mph wind with
diminishing improvement until there is no effect above 42mph. The 530G
turbine array was a very successful research and development project
that gained Wind Harvest its new international patent (6784566) on the
vortex effect and provided other important insights. The guyed wires
produced problems for turbine bearings and led to the conclusion to
return to an external superstructure in future models. Read more... |  |
 | Model 530In 1987 Wind Harvest successfully worked with the Second Heavy Machinery Plant in the People's Republic of China to fabricate a manufacturing prototype of the Model 530. This machine used less expensive aluminum blades (instead of fiberglass). These turbines were operated and maintained in the turbulent and energetic winds of the San Gorgonio Pass, California. With this version of the Model 530, Wind Harvest gained valuable operational experience which led to a turbine design that is durable, very efficient and easy to maintain. Read more... |
Model 480
In 1975 Bob Thomas envisioned a straight bladed, vertical axis turbine. With the financial help of the company cofounder and famous artist Sam Francis, he built increasingly larger versions of the turbine. In 1983, after he left his position as the director of Wind Energy for the California Energy Commission, Wind Harvest built three Model 480 turbines near Concord California. This early prototype with 480 square feet of swept area provided excellent information on turbine efficiency and future design improvements. Read more... |  |
.