Technology and Patents


WHI brings to the international wind harvesting industry a durable, elegant and efficient vertical axis wind turbine and breakthrough ways of placing arrays of VAWTs to maximize the energy densities and economic returns of wind projects.

The G168 VAWT evolved from years of prototyping and field-testing different iterations of 33% solidity, straight-bladed VAWTs. The G168 made the leap to an H-type, 11% solidity rotor and variable speed generation based in part on the modeling done by Iopara Inc with the help of a grant from California Energy Commission’s EISG program.

Turbine Profile

Power Output  70 kW

  • Total Height  18m
  • Rotor Diameter  12m
  • Variable Speed Operation

Annual Production

Wind speed at 10m height

  • 6.5 m/sec    161 MWh
  • 7.5 m/sec     213 MWh
  • 8.5 m/sec     260 MWh

Additional Facts

  •  Swept Area   168 m2
  • Operating Wind Speed  3-25 m/sec
  • Design Lifetime    25 years
  • Generator:  variable speed, permanent magnet
WHI Power Curve

Power Curve

Rotational Speed

WHI Power Coefficient

Power Coefficient

Summary of Attributes

Wind Harvest International Vertical Axis Wind Turbine Systems (WHI VAWT Systems)


  • Low height profile:  18m as opposed to 130m of the Siemens 2.3MW—1/7 the height of HAWT and blending in with natural environment
  • Highly efficient turbines individually, that enable linear arrays to capture the couple vortex effect, raising efficiency even further
  • Lower footprint for installation and infrastructure
  • Modular, enabling design more easily adaptable to the site
  • Lower acoustic impact than HAWT
  • Avian and wildlife friendly
  • Similarly efficient when set up in linear arrays, utilizing the coupled vortex
  • Cost competitive with HAWTs
  • Local workers can be trained for installation/operations/maintenance
  • Regional qualified steel manufacturers can secure license to produce turbines – job development
  • Turbine System from a quality company with decades of field experience in VAWT wind energy

Coupled Vortex Effect

The CEC was interested in WHI’s Coupled Vortex patent, invented by WHI founder Bob Thomas after he observed the Windstar 1066 (link to photo) rotor’s effects on its outside stators. WHI tested the impact of the Coupled Vortex Effect (CVE) on three 33% solidity VAWT prototypes (link to photo) set in a linear array in Palm Springs, California. The center turbine in the array realized a ~75% increase in energy output over when it operated as a single turbine for a year. Other VAWT companies have recognized the value of the CVE, and one in particular has proposed using this effect with their large, offshore VAWTs.

WHI fully expects that other VAWT and major HAWT Original Equipment Manufacturers (OEM) will begin making VAWTs for the worldwide wind farm “understory” market soon after WHI proves that VAWTs can be as cost efficient as HAWTs and can safely operate beneath and around them. The market is simply too large to ignore. These OEMs will find it quite profitable to use WHI’s patents to place their VAWTs close together in arrays that best increase the density of VAWTs on the land and benefit down wind HAWTs. Without the use of WHI’s placement patents a VAWT project would never be able to realize the full financial return otherwise available from the capital expense.

If you are interested in being on a mailing list where WHI shares new information about VAWT related R&D or if you wish to share information you have found related to VAWT impacts on HAWTs, please contact us at

History of WHI Technology

A Story of Innovation, Integrity, and Tenacity

“Engineering for wind energy turbines is like trying to build a car that has the characteristics of a Prius, a Ferrari, and a tractor, with the price tag of an Hyundai.”

Bob Thomas, WHI Co-Founder and Design Engineer


Like many innovators, what Bob found most intriguing and compelling what was NOT being explored by the US government wind programs in the 1970s. His instincts in the field and labs told him that smaller, simpler, less expensive, and more durable VAWTs had an important role to play in wind energy’s future.