Patent Application
20120204922
Embodiments are generally related to thermoelectric power generation methods and systems. Embodiments are additionally related to heat exchangers. Embodiments are further related to thermoelectric roofing materials.
Electrical energy can be easily transmitted to remote locations via an electrical conductor and without the requirement of mechanical transport. Electrical energy may be employed for heating, lighting, the generation of mechanical motion via a motor and an actuator, and also to power electronic and other devices. In less developed parts of the world, however, the supply of electricity is unreliable and completely unavailable in remote locations. As a result, there exists a need for a simple and cost efficient generation of electrical power on a localized basis.
The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice versa. A thermoelectric device includes a thermoelement that creates a voltage when there is a different temperature on each side (Seebeck effect). Conversely, when a voltage is applied to the thermoelectric device a temperature difference (Peltier effect) is created. Such thermoelements may be configured utilizing a conductor such as bismuth and/or antimony, whereas higher efficiency thermoelectrics can be built utilizing a heavily doped semiconductor.
One example of a thermoelectric approach to power generation is disclosed in U.S. Patent Publication No. 2010/0154855 entitled “Thin Walled Thermoelectric Devices and Methods for Production Thereof,” which published on Jun. 24, 2010 and is incorporated herein by reference in its entirety. Another example of a thermoelectric approach for generating electricity is disclosed in U.S. Pat. No. 6,127,766, which issued to R. Michael Roidt on Oct. 3, 2000, and which is als incorporated by reference in its entirety.
In general, thermoelectric generation takes place when a temperature difference is applied to the thermoelements, causing mobile charge carriers, either electrons or holes, to migrate from hot to cold. The resulting separation of charge creates an electric potential known as the Seebeck voltage. A Seebeck coefficient for a material may be positive or negative depending upon the type of majority charge carrier.
The majority of prior art thermoelectric power generation systems appear suitable for specialized applications and are not harnessed to generate electric power for use on a localized basis. Additionally, in remote environments, production of the thermoelectric power from such conventional means can be very difficult.
Based on foregoing, it is believed that a need exists for an improved thermoelectric roofing apparatus and method for generating electricity as a byproduct of heat exchange, as described in greater detail herein.
The following summary is provided to facilitate an understanding of some of the innovative features unique to the disclosed embodiments and is not intended to be a full description. A full appreciation of the various aspects of the embodiments disclosed herein can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
It is, therefore, one aspect of the disclosed embodiments to provide an improved thermoelectric power generation system and method.
It is another aspect of the disclosed embodiments to provide for an improved thermoelectric roofing material for generating electricity on a roof structure as a byproduct of heat exchange.
The aforementioned aspects and other objectives and advantages can now be achieved as described herein. A thermoelectric roofing apparatus and method for generating electricity as a byproduct of heat exchange is disclosed herein. A thermoelectric coating can be applied on a heat exchanger material (e.g., a roofing material, a shingle, etc.) located on a building (e.g., home or business) utilizing a thermoelectric coating process (e.g., spray-on coating) in order to capture waste heat from a heat source and generate an electrical energy. The thermoelectric coating can be a semiconductor material that can be applied to the heat exchanger material in a printed circuit format. The charge carriers with respect to the semiconductor material can be excited when heat flows through the thermoelectric coating which can be harvested to generate the electrical power. Electrical conductors can be attached to the thermoelectric coating to transmit the electrical energy generated as a byproduct of heat exchange.
The thermoelectric coating acts as a thermal collector in order to capture heat from the heat source. The spray-on thermoelectric coating can be applied for improving the thermoelectric properties. The semiconductor material includes one or more p type thermoelements and n type thermoelements. The p type thermoelements and n type thermoelements can be connected in electrical series and in thermal parallel. The thermoelectric generation takes place when a temperature difference is applied to the thermo elements, causing mobile charge carriers, either electrons or holes, to migrate from hot to cold resulting in an electric potential known as the Seebeck voltage, Energy losses associated with the active thermoelectric element due to joule heating can be minimized as the thermo elements have a high electrical conductivity.
The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.
The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.
The embodiments now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. The embodiments disclosed herein can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The roofing material 150 can be, for example, a heat exchanger (e.g., a roofing shingle), depending upon design considerations. The thermoelectric coating 130 can be a semiconductor material that can be applied to the roofing material 150 in a printed circuit format. The spray-on thermoelectric coating 130 can be applied for improving the thermoelectric properties. The spray-on thermoelectric coating 130 can deposit one solid material on top of another by ejecting a high velocity heated powder onto a target surface so that the powder fuses into a solid with a good mechanical and thermal connection.
The thermoelectric apparatus 100 includes one or more p type thermoelements 165 and one or more n type thermoelements 160. The p type thermoelements 165 and the n type thermoelements 160 can be connected in electrical series and in thermal parallel via one or more conductors 155. The n-type thermoelectric material 160 is a metal, semimetal or semiconductor that can be employed for thermoelectric applications. The n-type doped semiconductor thermoelectric material 160 possesses the property to convert a portion of the heat flux (heat energy flowing through it) into electricity, with the majority electrical carrier being electrons.
The p-type thermoelectric material 165 is a metal, semimetal or semiconductor that can be utilized for thermoelectric applications. The p-type doped semiconductor thermoelectric material 165 possesses the property to convert a portion of the heat flux into electricity with the majority electrical carrier being holes. The charge carriers associated with the thermoelements 160 and 165 can be excited when heat flows through the thermoelectric coating 130 which can be harvested to generate the electrical power. Electrical conductors can be attached to the thermoelectric coating 130 to transmit the electrical energy generated as a byproduct of heat exchange to, for example, an electrical grid 180. Note that as utilized herein the term “electrical grid” can refer to a large scale electrical grid for transferring electricity to multiple homes, buildings, and other facilities, or may refer simply to the “electrical grid” within a single home, building or other facility.
Thermoelectric generation takes place when a temperature difference is applied to the thermoelements 160 and 165, causing mobile charge carriers, either electrons or holes, to migrate from hot to cold resulting in an electric potential known as the Seebeck voltage. The heat source 110 can be, for example, solar energy, transferring its energy to the thermoelectric apparatus 100 by conduction. In some embodiments, heat source 110 can transfer energy to the thermoelectric apparatus 100 exclusively through radiative heat transfer. Energy losses associated with the active thermoelectric elements 160 and 165 due to joule heating can be minimized due to their high electrical conductivity. Furthermore, the electrical grid 180 can be disposed to collect the electrical energy from the thermoelectric apparatus 100 before the electrical energy is transmitted.
The generated electrical charge can then be employed to power a load, thus converting the thermal energy into electrical energy. The electrical grid 180 can be a resistive load such as a heater or an incandescent light, or it can be an electronic converter unit that converts the electrical power generated by the thermoelectric generation unit 150 into a different form. Note that the embodiments discussed herein should not be construed in any limited sense. It can be appreciated that such embodiments reveal details of the structure of a preferred form necessary for a better understanding of the invention and may be subject to change by skilled persons within the scope of the invention without departing from the concept thereof.
It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
