Energy from the wind has been harnessed for thousands of years, making wind power one of the oldest forms of renewable energy. Early windmills were used for pumping water or grinding grain. With the onset of industrialization, people began adapting windmills into wind turbines used for generating electricity.
Wind farms are built in geographical areas that are conducive to consistent prevailing winds. For utility-sized applications, many wind turbines are built in close proximity to one another to form a "wind farm." On these wind farms, giant wind turbines harness the kinetic energy in wind to create electricity. CPS Energy, through contracts with companies who design, build and operate wind farms, acquire designated portions of the electrical generation from those farms.
The process of wind-produced electrical generation begins when the force of the wind pushes against the turbines’ blades, causing them to rotate, creating mechanical energy. The spinning blades, attached to a hub and a low-speed shaft, turn along with the blades. The rotating low-speed shaft is connected to a gearbox that connects to a high-speed shaft on the opposite side of the gearbox. This high-speed shaft connects to an electrical generator that converts the mechanical energy from the rotation of the blades into electric energy. Spinning between 11 and 20 times per minute, each turbine can generate a maximum 1.5 megawatts of electricity -- enough to power, on average, more than 500 residential homes.
Energy generated by wind farms is transmitted to regional electric grids. For example, CPS Energy’s wind farms transmit power to the Electric Reliability Council of Texas (ERCOT) grid which manages the flow of electric power to Texas customers and schedules power for thousands of miles of transmission lines and hundreds of generation units. Once that wind power reaches the grid, it is hard to determine where it is distributed. Therefore, a CPS Energy customer at a 20 percent Windtricity participation level will not necessarily receive 20 percent of their electricity as wind power. Really, a customer’s participation level indicates their support for the continued generation of wind power and reduces the community’s dependence on traditional fuel sources.