An Apple patent (number 20120326445) for on-demand generation of electricity from stored wind energy has appeared at the U.S. Patent & Trademark Office. Is Apple looking to enter the wind energy market (unlikely) or is this a method of providing energy for its various headquarters and buildings?
The patent — with Jean L. Lee as the inventor — provides a system that generates electricity and stores rotational energy from a wind turbine as heat — then using the stored heat to subsequently generate electricity on demand. During operation, the system uses a set of rotating blades to convert rotational energy from a wind turbine into heat in a low-heat-capacity fluid. Next, the system selectively transfers the heat from the low-heat-capacity fluid to a working fluid. Finally, the system uses the transferred heat in the working fluid to generate electricity.
Here’s Apple’s background on the invention: “Wind energy technology is typically used to convert kinetic energy from wind into mechanical energy and/or electricity. To harness wind power, a wind turbine may include a set of blades and a rotor shaft connected to the blades. Wind blowing over the blades may cause the blades to turn and the rotor shaft to rotate.
“In addition, the rotating rotor shaft may be coupled to a mechanical system that performs tasks such as grinding grain and/or pumping water. Alternatively, the rotor shaft may be connected to an electric generator that converts the rotational energy into electricity, which may subsequently be used to power a motor vehicle, home, business, and/or electrical grid.
“However, the variable nature of wind may interfere with on-demand generation of electricity from wind energy. For example, fluctuations in wind speed may hamper the adequate production of electricity from wind power during periods of peak demand, or conversely, may produce excess electrical power during periods of low demand. In turn, such variability may limit the ability to incorporate large amounts of wind power into a grid system.
“For example, other power stations (e.g., coal, natural gas, hydroelectric, nuclear) may be required to offset variations in electricity generated from wind power and maintain reliable electric service in an electrical grid. Hence, what is needed is a mechanism for mitigating variability and/or intermittency associated with the production of electricity from wind energy.”