The present invention relates to generation of electricity and heat from incoming solar radiation (insolation). More specifically, the present invention relates to fluid cooled panels that utilize thermoelectric generation and/or photovoltaic cells.
The terms “cold” and “hot” are used relatively herein, not absolutely. Fluid is labeled “cold” if it tends to be cooler than fluid that is labeled “hot”. Fluid is labeled “hot” if it tends to be warmer than fluid that is labeled “cold”.
This description provides embodiments of the invention intended as exemplary applications. The reader of ordinary skill in the art will realize that the invention has broader scope than the particular examples described here. It should be noted from the outset that the drawings, and the elements depicted by the drawings, may not be to scale.
The STG 200 heats a liquid by exposure to sunlight. The liquid might be ethylene glycol, water, or some other liquid. Some of the heat is then removed from the liquid into a heat reservoir 261, resulting in cold (i.e., cooler) liquid. The cold liquid and the hot liquid are placed into thermal contact with each other at a thermoelectric interface 201, such as interface interface 201a or interface 201b, where electricity is generated. Although in
The generated electricity may be stored in any technology for storing electricity, such as batteries, or the current may be used, wholly or in part, as it is generated to drive a circuit. The STG 200 may also store heat, in a heat reservoir 261, or simply remove it in a heat sink (not shown).
The STG 200 embodiment illustrated in
Note that other configurations of the panels 220 are possible within the scope of the invention. For example, the panels 220 might be installed on a rooftop. In such a configuration, the frame holding them might be horizontal, or at some acute angle with the horizontal.
Other than
The panels 220 themselves are similar to those described in U.S. Pat. No. 8,650,877 (the '877 patent), entitled “Solar Panels that Generate Electricity and Extract Heat: System and Process”, which issued on Feb. 18, 2014, and is hereby incorporated by reference in its entirety. This patent describes illustrative mechanisms for rotating panels 220 in a blind 221, such as the panels 220 described herein, to keep them solar-facing.
The panels 220 are also similar to those described in application number PCT/US14/10650 (the '650 application), filed Jan. 8, 2014, which is hereby incorporated by reference in its entirety. The inventions described in the '877 patent and the '650 application use thermal expansion to drive electrical generators. Indeed, any of the panel configurations described in those documents, and the means for opening and closing them (e.g.,
As will be described below, there are many applications of the present invention in addition to solar panels. However, solar panel embodiments illustrate many of the concepts, and so will be our main focus in this description.
It should be noted at this point that the figures contain many symmetries and many repeated features. When redundant labeling would obscure rather than enhance readability of the figures, some reference numerals have been omitted. We will follow the convention that reference numbers on the left side of the blind are labeled with a numeral followed by ‘a’; their counterparts to the right, ‘b’. To indicate some feature that is in common to left- and right-side components, we will drop the ‘a’ and ‘b’. For example, the embodiment shown has a left interface interface 201a, and a right interface interface 201b, each of which is a thermoelectric interface 201. Generally, for clarity we will omit a generic/common label in the drawings when corresponding left and right components are explicitly labeled.
A set of solar panels 220 may be assembled into a blind 221. The illustrative blind 221 in
The lateral and vertical extents of the panels 220 of the blind 221 are labeled in the figure with braces. The STG 200 includes a fluid transport system, which may be any combination of pipes, flexible tubing, connectors, channels, and valves. We will refer to this fluid transport system as a conduit or tubing system in this document, without loss of generality. In particular, “tubing” does not necessarily imply flexible tubing. Fluid in a cavity or channel within the body of a panel 220 is heated through the outer window pane by incoming solar radiation. Fluid flow may be forced by one or more pumps 260, or by thermal expansion of fluid due to heating as described in '877 patent.
Conservation of mass and the conduit system govern the flow direction at any point, designated by arrows in the figures. Thin arrows, typified by arrow 230, arrow 240, and arrow 250a, indicate “cold” fluid. Thicker and darker arrows, typified by arrow 231, arrow 241, and arrow 251b, indicate “hot” fluid.
In the embodiment shown, each panel 220 of the blind 221 has an internal channel 222 or tube. The panels 220 and the channels 222 may be produced, for example, by extrusion of a metal such as aluminum, or a metal alloy. In other embodiments, a panel 220 might enclose a pipe or tube. Preferably but not necessarily, all panels 220 in a single window will be similarly configured. Some channel embodiments are illustrated in the '877 patent. In the embodiment shown, adjacent panels 220 have flow in opposite directions, as indicated by arrows in
Cold fluid enters a panel 220 from a cold manifold 203, such as cold manifold 203a or cold manifold 203b. The cold manifold 203 is in thermal contact with a hot tank 205, such as hot tank 205a or hot tank 205b, through which hot fluid that has exited from (in this embodiment) half of the panels 220 flows. Partitioning into cold manifolds 203 prevents flow of cold fluid in the z-direction, preventing the cold fluid from warming up much except within the panels 220. This approach maintains the temperature difference across the thermoelectric generating interface 101 between cold manifold 203 and hot tank 205.
As shown by
In
So far in this document, we have described a set of solar panels 220, formed into a blind 221, that use thermal contrasts to generate electricity, and a cooling system to enhance the thermal contrast and to remove heat from the panels 220—heat that can be applied to other uses.
Many types of photovoltaic cells 151 lose effectiveness in generating electricity when they get hot. A panel cooling system such as the one already described can be used to remove heat from the embedded photovoltaic cell modules 150. Thus, the cooling system can serve the dual purposes of maintaining a thermal contrast for thermoelectric generation and improving effectiveness of the photovoltaic cell modules 150.
Effectiveness of photovoltaic cells 151 is also known to be degraded by infrared (IR) radiation. Many modern buildings use a window coating to filter out incoming IR radiation. In embodiments in which the panels 220 are behind a window pane, such a filtering layer is preferable.
Note, however, that photovoltaic cell electricity generation might also be used without thermoelectric generation. In such embodiments, the cooling system might be simplified, since maintaining a temperature contrast across an interface would no longer be essential. But the cooling system, in such embodiments, would nevertheless to cool the photovoltaic cells 151, improving their effectiveness. This implies that (1) flow might not alternate between adjacent panels; and (2) manifolds to maintain temperature contrast might not be used.
The inventive concept is not limited to panels 220 in a blind 221. The same system configuration might be adapted, for example, to a parking lot or within the roof of a building. As mentioned previously, a STG 200 can also be run in reverse, using external cooling and stored hot fluid. Note too that adjacent windows could share components, such as hot tanks 205, cold manifolds 203, and cold tanks 210.
Of course, many variations of the above method are possible within the scope of the invention. The present invention is, therefore, not limited to all the above details, as modifications and variations may be made without departing from the intent or scope of the invention. Consequently, the invention should be limited only by the following claims and equivalent constructions.
This application claims the benefit of provisional U.S. Application No. 62/181,798, filed Jun. 19, 2015, and hereby incorporated by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US16/36630 | 6/9/2016 | WO | 00 |
Number | Date | Country | |
---|---|---|---|
62181798 | Jun 2015 | US |