Wind power has been around for hundreds of years—initially as wind mills to pump water and more recently as electric-power-producing wind turbines. The most dramatic and obvious change in wind power has been in the size and shape of the blades. We are all familiar with the classic Dutch windmills that had wide, flat blades. The current generation of wind mills with slender, narrow blades is a common site across North America.
As readers of this column know, we look ahead to the technologies that were recently patented and that are likely to be implemented in the near future. But we always first take a look back, and this column’s look-back takes us back to 19th century Cleveland, the center of high technology at the height of the Industrial Revolution. Charles Brush, owner of an engineering firm, had his company build a wind turbine in 1888. It provided electrical power to his home and laboratory. Brush’s wind turbine was mounted on a 60-foot tower with rotor blades that were 56 feet in diameter. It turned very slowly as it had 144 blades that covered 1,800 square feet of surface! The machine generated only 12 kW, and it charged a bank of batteries that provided power to three arc lamps and various motors in Brush’s laboratory. The machine provided reliable and inexpensive electricity until 1908 when Brush switched over to power from the local utility.
One of the earliest of the modern wind turbine patents was U.S. Patent No. 2,360,791 for a “Wind Turbine” issued in 1944. The inventor was one Putnam Palmer Cosslett and the patent was assigned to the S. Morgan Smith Company, a manufacturer of “power-transmitting machinery, boilers and flume work.” S. Morgan Smith Company was acquired by Allis Chalmers, the farm equipment OEM, in 1959, and the business unit was spun off in 1983 as Precision Custom Components which is still in business today with a factory and corporate offices in York, Pennsylvania.
As we do in each installment of Follow the Patents, we will peer into the future by examining four wind power patents that have applications for electric utilities:
U.S. Patent No. 9,118,221 for a “Magnetic Propulsion Motor” is part of a five-patent portfolio from Future Force LLC. This is the newest of the patents in the portfolio and was published in 2015. The patents address the electrical power that is lost in a typical wind turbine generator of today from drag and friction between the blades and the turbine. While the title of the patent uses the term “motor” it is really a next-generation, low-friction transmission for wind turbines. Using magnets to replace bearings and other components, the invention covered by this portfolio dramatically reduces the friction and drag created by traditional wind turbine power trains, and that increases the power-generation capabilities of the wind turbine. It also creates a transmission that lasts longer than transmissions now in use and it requires far less maintenance. The transmission covered by this patent can be retro-fitted into current wind turbines or designed into the next generation.
U.S. Patent No. 9,273,666 for a “Magnus Type Wind Power Generator” was issued to inventor Hamid Reza Kheirandish just last year, and it represents a new design in wind turbines that has revolving blades. The invention covered by the patent relies on what is known as the “Magnus Effect” in which a spinning object “drags” the air faster on one side than the other. The Magnus Effect explains why a spinning golf ball curves away from its original flight path and ends up in the rough. Reversing the Magnus Effect, this invention has rotary shafts that catch the wind, and the difference in air pressure causes these shafts to spin, and that creates a rotating a horizontal rotary shaft that generates electric power.
U.S. Patent No. 9,194,843 for a “Method and Apparatus for Monitoring Wind Turbine Blades During Operation” was assigned in 2015 to Digital Wind Systems, Inc., and the patent addresses monitoring the operation of a wind turbine. Like the new tire pressure warning system on cars, the invention covered by this patent uses a sensor that is located on the blade root end bulkhead so it receives airborne acoustic signals that will indicate any anomalies in the turbine blades as they rotate. A three-axis accelerometer determines the gravity vector and other sources of cyclic acceleration indicated by the acoustic signals received by the sensor, and a signal-analysis system analyzes the signals to provide critical data for managing and maintaining the wind turbine.
U.S. Patent No. 9,133,824 for a “Wind Turbine and an Associated Yaw Control Method” was issued in 2015 and is assigned to Envision Energy, Aps. To understand the invention, you must know what “yaw” is. If you are a sailor or a pilot, you know that the forces on a boat or aircraft are roll, pitch and yaw. On a wind turbine, “yawing” is getting the blades of the turbine to face directly into the wind so they catch optimal wind force. The invention covered by this patent controls the yawing of a two-bladed wind turbine. The challenge is not to simply catch the wind from the direction it is blowing, but to also catch the wind from the angle is it blowing. This invention adjusts both the vertical and horizontal by modulating the yaw rate based on the rotational angle of the blades.
Next time: Utilities balance supply and demand by storing excess power that can be released when need. In the next Follow the Patents, we take a look at cutting-edge technologies in electrical energy storage.