Wind Energy Harvesting Capability of a Novel Cascaded Dual-Rotor Horizontal-Axis Wind Turbine

With the global demand for electrical energy increasing rapidly due to factors such as population and economic growth, energy sourced from fuels subject to price uncertainty can have negative effects on economic development. Sourced from wind, a clean and free renewable resource, wind energy does not act as a pollution vector unlike power plants which operate on fossil fuels such as coal or natural gas. With environmental protection and sustainability at the forefront of our global society with a concentrated effort for corporate social responsibility, more focus is placed on renewable technologies such as wind turbines. After solar energy, wind energy is currently one of the cheapest forms of electrical energy to produce, and this number can be further reduced. Wind farms requires substantial parcels of land as wind turbines must be spaced approximately seven times their rotor diameter apart from each other, and the larger the wind turbines are the larger this spacing becomes, requiring even more real estate. As such, a method is sought to increase the amount of electrical energy each wind turbine can produce without altering efficiency or size. If the amount of power that a wind farm can produce is to be increased but neither the size of the wind farm's physical location can be increased for additional wind turbine placement nor the size of the wind turbines themselves increased, then the electrical power can be increased by utilizing a novel Horizontal-Axis Wind Turbine (HAWT) design. This modified wind turbine design features an additional independent rotor behind the original rotor which allows for more power-generation opportunities. The scope of this research is to evaluate the performance of a novel Cascaded Dual-Rotor Horizontal-Axis Wind Turbine (CDR-HAWT) and compare it with the performance of a typical single-rotor HAWT. For this purpose, the CDR-HAWT was fabricated with the same critical dimensions and electrical tolerances as a typical single-rotor HAWT. In order to compare the performances of the two independent wind turbines, the CDR-HAWT along with a typical HAWT with identical generator size, nacelle and hub size, and blade geometry, are mounted onto the bed of a truck to be tested at different wind speeds. The voltage and power produced by the two wind turbines are measured across a resistive load using a digital storage oscilloscope (DSO). From testing it is determined that the CDR- HAWT produces approximately 84 percent additional power as compared to a typical single-rotor HAWT.