WO2005101525A2

WO2005101525A2 - Structures and apparatuses including photovoltaic cells

Info

Publication number: WO2005101525A2
Application number: PCT/US2005/013108
Authority: WO
Inventors: Isaac Berzin; Erik C. Bue
Original assignee: Greenfuel Technologies Corporation
Priority date: 2004-04-14
Filing date: 2005-04-14
Publication date: 2005-10-27
Also published as: WO2005101525A3

Abstract

Certain aspects of the present invention involve combining one or more photovoltaic cells, or films or panels containing such cells, with apparatuses and structures designed to contain, shield, and/or enclose one or more photosynthetic organisms and/or with apparatuses or structures comprising a solar thermal energy collection device, such as a solar heat exchanger. In certain embodiments, the photovoltaic cells utilized in the context of the present invention are of a type that are at least partially transparent to light of least one wavelength capable of driving photosynthesis, such as at least one wavelength between about 400 nm and about 700 nm corresponding to one or more absorption bands for a selected photosynthetic organism, and/or are at least partially transparent to of least one wavelength of infrared radiation.

Description

STRUCTURES AND APPARATUSES INCLUDING PHOTOVOLTAIC CELLS

Related Applications This non-provisional application claims the benefit under Title 35, U.S.C. §119(e) of co-pending U.S. provisional application serial no. 60/561,979, filed, April 14, 2004, which is incorporated herein by reference.

Background

1. Field of the Invention The present involves apparatuses and methods employing transparent articles, such as solar panels, including photovoltaic cells, which may also be transparent in certain embodiments, in combination with photobioreactors and/or other structures enclosing or shielding photosynthetic organisms, for example methods and apparatuses in which light is used both for generation of electricity and driving photosynthesis, or in combination with a solar thermal energy collection device in which solar radiation is used both for generation of electricity and heating. 2. Description of the Related Art Photosynthesis is the process that converts energy in sunlight or other appropriate light sources to chemical forms of energy that can be used by biological systems. Photosynthesis is carried out by many different organisms, ranging from plants to bacteria. The best known form of photosynthesis is the one carried out by higher plants and algae, as well as by cyanobacteria and their relatives, which are responsible for a major part of photosynthesis in oceans. All these organisms convert CO₂ (carbon dioxide) into organic material by reducing this gas to carbohydrates in a rather complex set of reactions. Electrons for this reduction reaction ultimately come from water, which is then converted to oxygen and protons. Energy for this process is provided by light, which is absorbed by pigments (primarily chlorophylls and carotenoids) in the photosynthetic organisms. Chlorophylls absorb blue and red light and carotenoids absorb blue-green light, but green and yellow light are not effectively absorbed by photosynthetic pigments in plants; therefore, light of these colors is either reflected by leaves or passes through the leaves. This is why plants are green. Most plants have Chlorophylls a and b. Algae on the other hand have pigments complexed with proteins (Table 1), which causes a shift in the absorption maxima to the red end of the spectrum by up to 90nm (Table 2).

Table 1: Distribution of pigments in algal classes (source: CSIRO Marine Research)

Table 2: Absorption by chlorophylls and pigments (source: CSIRO Marine Research)

Pigment In vivo maxima (nm) Chlorophyll a 435 675 Chlorophyll b 470—490 650 Chlorophyll c 450 630 Carotenoids 475" ^■540 Phycocyanin 580- 600 Phycoerythrin 540-565

Photovoltaic cells that are able to utilize solar or other light energy for generating electrical current flow are also known. Recently, photovoltaic cells and films have been developed that are based on dye-sensitized nano-scale particulate materials and that can be manufactured to have thicknesses and from materials allowing them to be at least partially transparent to visible light. Such photovoltaic cells and films have been described, for example, in Gratzel M., "Molecular Photovoltaics that Mimic Photosynthesis," Pure Appl. Chem., 73: p.459 (2001) (Gratzel 2001(a)); and Gratzel M., "Photoelectrochemical Cells," Nature, 414: p.338 (2001) (Gratzel 2001(b)); O'Regan B., Gratzel M., "A Low Cost High Efficiency Solar Cell Based on Dye-Sensitized Colloidal TiO2 Films," Nature, 353: p.737 (1991) (O'Regan and Gratzel 1991); and U.S. Pat. No. 6,706,963. Also known are apparatuses and systems comprising one or more solar thermal energy collection devices, which are configured to convert components of solar radiation, for example, infrared radiation, into heat energy, which may be utilized to, for example, heat dwellings, fluids, etc. For example, solar thermal energy collection devices have been utilized for a variety of residential and commercial water and/or air heating purposes. A wide variety of such solar thermal energy collection devices configured as heat exchangers and/or heat collectors are known and are commercially available. Such apparatuses and systems can be utilized, for example, as water heaters for home and/or commercial use, as living space air intake heaters, as process heat exchangers for various industrial applications, etc.; as in swimming pool water heaters, etc.

Summary In one aspect of the invention, a variety of apparatuses, systems, and devices are disclosed. In one set of embodiments, an apparatus or structure is disclosed comprising: an article comprising a photovoltaic cell, is the article being at least partially transparent to light of at least one wavelength capable of driving photosynthesis; and a photosynthetic organism capable of undergoing photosynthesis upon exposure to light of at least one wavelength to which the article is at least partially transparent, wherein the article is positioned between the photosynthetic organism and a source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the article. In certain embodiments, the photovoltaic cell is at least partially transparent to light of at least one wavelength capable of driving photosynthesis, and the article is positioned between the photosynthetic organism and the source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the photovoltaic cell. In another set of embodiments, an apparatus is disclosed comprising: a photobioreactor containing a liquid medium therein comprising at least one species of photosynthetic organisms, at least a portion of the photobioreactor being configured to transmit light capable of driving photosynthesis to the photosynthetic organisms; and an article comprising a photovoltaic cell, the article being configured and positioned with respect to the photobioreactor to transmit light capable of driving photosynthesis to the photosynthetic organisms. In certain embodiments, the photovoltaic cell is at least partially transparent to light of at least one wavelength capable of driving photosynthesis, and the article is positioned between the photosynthetic organism and the source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the photovoltaic cell. In another set of embodiments, an enclosure is disclosed comprising: an article comprising a photovoltaic cell, wherein the article is at least partially transparent to light of at least one wavelength capable of driving photosynthesis; and a photosynthetic organism capable of undergoing photosynthesis upon exposure to light of at least one wavelength to which the article is at least partially transparent, wherein the article is positioned between the photosynthetic organism and a source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the article. In certain embodiments, the photovoltaic cell is at least partially transparent to light of at least one wavelength capable of driving photosynthesis, and the article is positioned between the photosynthetic organism and the source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the photovoltaic cell. In another set of embodiments, an apparatus or structure is disclosed comprising: an article comprising a photovoltaic cell, the article being at least partially transparent to solar radiation, for example infrared radiation, of at least one wavelength; and a solar thermal energy collection device, wherein the article is positioned between the solar thermal energy collection device and a source of solar radiation so that at least a portion of the solar radiation reaching the solar thermal energy collection device passes through the article. In certain embodiments, the photovoltaic cell is at least partially transparent to infrared radiation of at least one wavelength and the article is positioned between the solar thermal energy collection device and the source of solar radiation so that at least a portion of the solar radiation reaching the solar thermal energy collection device from the source of solar radiation passes through the photovoltaic cell. In another aspect, the invention describes a series of methods. In one set of embodiments, a method is disclosed comprising: positioning an article that is at least partially transparent to light of at least one wavelength capable of driving photosynthesis and comprising a photovoltaic cell between a photosynthetic organism and a source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the article. In certain embodiments, the photovoltaic cell is at least partially transparent to light of at least one wavelength capable of driving photosynthesis, and the article is positioned between the photosynthetic organism and the source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the photovoltaic cell. In another set of embodiments, a method is disclosed comprising an act of: facilitating the generation of electricity and photosynthesis by providing an article comprising a photovoltaic cell, wherein the article is at least partially transparent to light of at least one wavelength capable of driving photosynthesis. In certain embodiments, the photovoltaic cell is at least partially transparent to light of at least one wavelength capable of driving photosynthesis. In another set of embodiments, a method is disclosed comprising an act of: positioning an article that is at least partially transparent to solar radiation of at least one wavelength and comprising a photovoltaic cell between a solar thermal energy collection device and a source of solar radiation so that at least a portion of the solar radiation reaching the solar thermal energy collection device from the source of solar radiation passes through the article. In certain embodiments, the article is at least partially transparent to infrared radiation of at least one wavelength. In certain embodiments, the method further comprises absorbing at least a portion of the solar radiation with the photovoltaic cell, thereby generating an electrical current with the photovoltaic cell. In certain embodiments, the photovoltaic cell is at least partially transparent to infrared radiation of at least one wavelength and the article is positioned between the solar thermal energy collection device and the source of solar radiation so that at least a portion of the solar radiation reaching the solar thermal energy collection device from the source of solar radiation passes through the photovoltaic cell. In certain embodiments, the method further involves transmitting at least a portion of the solar radiation comprising the infrared radiation of at least one wavelength through the photovoltaic cell and impinging the portion of the light transmitted through the photovoltaic cell on the solar thermal energy collection device, thereby transferring thermal energy to the thermal energy collection device. In another set of embodiments, a method is disclosed comprising: facilitating the generation of electricity and the operation of a solar thermal energy collection device by providing an article comprising a photovoltaic cell, wherein the article is at least partially transparent to solar radiation of at least one wavelength. In certain embodiments, the article is at least partially transparent to infrared radiation of at least one wavelength. In certain embodiments, the photovoltaic cell is at least partially transparent to infrared radiation of at least one wavelength. In another aspect, the invention provides kits. In one set of embodiments, a kit is disclosed comprising: an article comprising a photovoltaic cell, wherein the article is at least partially transparent to light of at least one wavelength capable of driving photosynthesis; and instructions directing a user to position the article between a photosynthetic organism and a source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the article. In certain embodiments, the photovoltaic cell is at least partially transparent to light of at least one wavelength capable of driving photosynthesis, and the instructions direct a user to position the between the photosynthetic organism and the source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the photovoltaic cell. Brief Description of the Drawings The accompanying drawings are schematic are not intended to be drawn to scale. In the figures, each identical, or substantially similar component that is illustrated in various figures is typically represented by a single numeral or notation. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention. In the drawings: FIG. 1A is a schematic illustration of a solar panel comprising a photovoltaic cell interposed between a plant and the sun, according to certain embodiments of the invention; FIG. IB is a schematic illustration of a greenhouse including a photovoltaic cell and having plants therein, according to certain embodiments of the invention; FIG. 1C is a schematic illustration of a building including various configurations for providing articles comprising a photovoltaic cell facilitating photosynthesis by plants within the building or within enclosures associated with the building, according to certain embodiments of the invention; FIG. ID is a schematic flow diagram and illustration of a solar water heating apparatus including a flat-panel solar thermal energy collection device including a solar panel comprising a photovoltaic cell, according to certain embodiments of the invention; FIG. IE is a partially cut-away of the flat-panel solar thermal energy collection device including a solar panel comprising a photovoltaic cell illustrated in FIG. ID; FIG. 2A is a schematic cross-sectional illustration of a photobioreactor apparatus including a photovoltaic cell, according to certain embodiments of the invention; FIG. 2B is a schematic cross-sectional illustration of a transparent tube of the photobioreactor of FIG 2A taken along line B - B and showing three possible ways of associating the photovoltaic cell with the tube; FIG. 3 A is a schematic cross-sectional illustration of a flexible, transparent photovoltaic film that can be employed to provide photovoltaic cells, according to certain embodiments of the invention; FIG. 3B is a schematic plan view of a transparent article comprising a plurality of stripes comprising photovoltaic cells, which may also be transparent, according to certain embodiments of the invention; FIG. 4 is a photocopy of a Scanning Electron Micrograph (SEM) image of a plurality of sintered TiO₂ nanoparticles that comprise a portion of the active layer of the flexible, transparent photovoltaic film of FIG. 3; FIG. 5 is a graph showing the absorbance versus wavelength characteristics of three similar Ruthenium-based dyes that can be utilized for dye-sensitization of the TiO₂ nanoparticles of the active layer of the flexible, transparent photovoltaic film of FIG. 3; FIG. 6 is a schematic diagram illustrating the operating mechanism of the transparent photovoltaic film of FIG. 3. Detailed Description Certain aspects of the present invention involve combining one or more photovoltaic cells, or articles such as films, or sheets, or panels containing such cells, with apparatuses and structures designed to contain, shield, and/or enclose one or more photosynthetic organisms. As will be described in greater detail below, in certain embodiments, the articles comprising the photovoltaic cells utilized in the context of the present invention, and in certain embodiments the photovoltaic cells themselves can be of a type that are at least partially transparent to light of least one wavelength capable of driving photosynthesis, such as at least one wavelength between about 400nm and about 700nm conesponding to one or more absorption bands for a selected photosynthetic organism (see Table 2 above). In certain embodiments, the present invention involves combining one or more photovoltaic cells, or articles such as films, or sheets, or panels containing such cells, with apparatuses and structures comprising a solar thermal energy collection, such as a solar heat exchanger or "black-body" heat collector. As will be described in greater detail below, in certain embodiments, the articles comprising the photovoltaic cells utilized in the context of the present invention, and in certain embodiments the photovoltaic cells themselves, can be of a type that are at least partially transparent to infrared radiation of least one wavelength, such as at least one wavelength between about 700nm and about 1 x 10⁶nm. As described in greater detail below, in certain embodiments, the above-mentioned transparent photovoltaic cells can comprise those of a class comprising active layer(s) including dye-sensitized nanoparticles, such as nanoparticles formed of metal oxide(s) (for example, titanium dioxide). Such photovoltaic cells can be fabricated as thin film solar cells and can comprise percolating networks of liquid electrolyte and dye-coated sintered, or otherwise fused, metal oxide nanoparticles. These photovoltaic cells were first developed by Doctor Michael Gratzel and coworkers at the Swiss Federal Institute of Technology and are described in, for example Gratzel 2001(a), Gratzel 2001(b), and O'Regan and Gratzel 1991, each of which is incorporated herein by reference. As described in more detail below, the materials and fabrication techniques utilized for forming such thin-film photovoltaic cells, and the particular dyes chosen for dye- sensitization of the nanoparticles, can enable such photovoltaic cells to be manufactured to be at least partially transparent to light of wavelengths useful for driving photosynthesis in photosynthetic organisms and/or to infrared radiation useful for solar heating applications. Thus, advantageously, certain inventive apparatuses and systems disclosed herein include an inventive incorporation of an article comprising a photovoltaic cell that, wherein the article, and in certain embodiments the photovoltaic cell itself, is partially transparent to light of at least one wavelength capable of driving photosynthesis in a device, structure, etc., which is configured for containing, shielding, enclosing, etc., one or more photosynthetic organisms. The invention also, in certain embodiments, provides for practice of a method comprising positioning such an article comprising a photovoltaic cell between a source of light, such as the sun, and a photosynthetic organism and absorbing a portion of the light incident upon the photovoltaic cell, thereby generating electricity with the photovoltaic cell, while also transmitting a portion of the incident light through the photovoltaic cell and/or article, such that it impinges upon and drives photosynthesis in the photosynthetic organism. Similarly, in certain embodiments, certain inventive apparatuses and systems disclosed herein include an inventive incorporation of an article comprising a photovoltaic cell that, wherein the article, and in certain embodiments the photovoltaic cell itself, is partially solar radiation, such as infrared radiation, of at least one wavelength in a device, structure, etc., which is comprises a solar thermal energy collection device and which configured for heating water, air, or other heat exchange media. The invention also, in certain embodiments, provides for practice of a method comprising positioning such an article comprising a photovoltaic cell between a source of solar radiation, such as the sun, and a solar thermal energy collection device and absorbing a portion of the solar radiation incident upon the photovoltaic cell, thereby generating electricity with the photovoltaic cell, while also transmitting a portion of the incident solar radiation through the photovoltaic cell and or article, such that it impinges upon the solar thermal energy collection device thereby driving heat exchange and/or heat collection. Certain embodiments of the present invention advantageously enable both beneficial growth of plants, algae, and other photosynthetic organisms, which can, for example, convert, pollutants such as CO₂ and NO_x into beneficial substances, for example, oxygen, and, at the same time, the generation of electricity from light, such as the sun, which can be utilized for various purposes, including, but not limited to, powering a motor, pump, computer, etc., associated with the apparatus, building, enclosure, etc. facilitating growth and maintenance of the photosynthetic organism. As explained in more detail below, such a combination has a wide variety of potential applications including, but not limited to, novel electricity- generating photobioreactors for growing algae or other photosynthetic microorganisms, electricity-generating greenhouses and terrariums, electricity-generating windows, window shades, window blinds, shade cloth etc., for green houses and "green buildings," and others. The term "photovoltaic cell" is given its ordinary meaning and refers to any device that is configured to convert solar energy and/or artificial light energy directly into electrical energy. A "photobioreactor," as used herein, refers to an apparatus containing, or configured to contain, a liquid medium comprising at least one species of photosynthetic organisms and having either a source of light capable of driving photosynthesis associated therewith, or having at least one surface at least a portion of which is partially transparent to light of a wavelength capable of driving photosynthesis (i.e. light of a wavelength between about 400- 700 nm). Certain photobioreactors for use herein comprise an enclosed photobioreactor system, as contrasted with an open bioreactor such as a pond, tank, or other open body of water. Preferred photobioreactors and photobioreactor systems for use in practicing the current invention are those described in Applicant's International Application Publication No. WO 03/094598, which is a publication of Applicant's co-pending International Application Serial No. PCT/US03/15364, which entered the national phase as U.S. Serial No. 10/514,224, Applicant's U.S. Patent Publication No. US 2005/0064577-A1, and Applicant's U.S. Non- provisional patent application titled: SYNTHETIC AND BIOLOGICALLY-DERIVED PRODUCTS PRODUCED USING BIOMASS PRODUCED BY PHOTOBIOREACTORS CONFIGURED FOR MITIGATION OF POLLUTANTS IN FLUE GASES, by Isaac Berzin, filed April 14, 2005, U.S. serial no. --/—,—, bearing attorney docket no. B1110.70003US01, which are each hereby incorporated by reference. The term "photosynthetic organism" as used herein includes all organisms capable of photosynthetic growth, such as higher plants and microorganisms (including algae and euglena) in unicellular or multi-cellular form. This term may also include organisms modified artificially, such as by selective breeding and/or directed evolution and/or by gene manipulation. The phrases "at least partially transparent to light of at least one wavelength capable of driving photosynthesis" and "configured to transmit light of at least one wavelength capable of driving photosynthesis," when used in the context of a surface or component, such as an article comprising a photovoltaic cell, or photovoltaic cell or film, refers to such surface or component being able to allow enough light energy to pass through, for at least some wavelengths and intensities of incident light energy exposure, so as to drive photosynthesis within a photosynthetic organism. The term "enclosure" as used herein refers to a structure providing at least one surface interposed between the thing contained within the structure and/or positioned in proximity to the structure, and a surrounding environment. For example, an enclosure would include, but would not be limited to a building structure with roof, walls, etc. completely surrounding the thing "enclosed" or a structure having only a roof, only walls, etc., at least one of which is interposed between the thing "enclosed" and a surrounding environment. Referring now to the figures, a variety of illustrative embodiments for providing various apparatuses, enclosures, and structures including a transparent article comprising a photovoltaic cell, which in certain embodiments may be at least partially transparent to light of least one wavelength capable of driving photosynthesis and/or at least one wavelength of infrared radiation, in combination with one or more photosynthetic organisms and/or solar thermal collectors is illustrated in FIGs. 1A-1E and FIGs. 2A and 2B. It should be understood that the illustrated embodiments comprise simply a few of the extremely wide variety of configurations that may be practiced utilizing the teachings of the present disclosure and no more than ordinary skill in the art. Suitable articles comprising photovoltaic cells, e.g. films, sheets, panels, etc. for practicing the present invention are described in greater detail on the context of FIGs. 3A-6. As mentioned previously, and as described in greater detail below, in certain embodiments, the photovoltaic cells advantageously comprise a thin-film photovoltaic cell based upon dye-sensitized nanocrystalline particles, such as metal oxides. Such photovoltaic cells, as explained in more detail below, can include one or more sensitizing dyes having an absorption spectra selected to absorb light, for the purpose of generating electricity, less strongly for at least certain wavelengths that are associated with in vivo absorption maximum for photosynthesis by particular photosynthetic organisms (e.g., such as certain wavelengths within the ranges previously illustrated in Table 2) and/or that comprise wavelength(s) in the infrared. Accordingly, such photovoltaic cells may be fabricated from materials and dyes that are selected to enable the photovoltaic cells to be able to transmit a suitable portion of incident light, of an appropriate wavelength for driving photosynthesis of a selected photosynthetic organism and/or can be fabricated from materials and dyes that are selected to enable the photo voltaic cells to be able to transmit a suitable portion of incident solar radiation, of an appropriate wavelength, e.g. infrared, for use in heating solar thermal energy collectors, during operation, while also absorbing sufficient quantities of light to enable the cells to generate a useable electrical current. FIG. 1 A illustrates, schematically, a basic interrelationship between a structure, such as solar panel article 100, a photovoltaic cell (102 and/or 102' and/or 102"), a photosynthetic organism (plant 104), and a source of light capable of driving photosynthesis (the sun 106). Specifically, panel 100 is positioned between photosynthetic organism 104 and sun 106 so that at least a portion of the light 108 reaching photosynthetic organism 104 passes through 110 the panel and, in the illustrated embodiment, the photovoltaic cell. FIG. 1 A illustrates that, in typical embodiments, light 112 produced by light source 106 will be incident upon panel 100, including the photovoltaic cell, and may be partially reflected 114, while an unreflected portion will comprise the portion 110 passing through panel 100 and forming light component 108 incident upon plant 104, as well as an additional component 116, which is absorbed by the photovoltaic cell and which is utilized for producing an electrical curcent 118. While, in the illustrated embodiment, the source of light 106 comprises the sun, in alternative embodiments, a variety of artificial light sources could be utilized instead of, or in addition to, the sun as a source of light energy. As indicated in FIG. 1 A, there exists a variety of possible configurations for providing and positioning a photovoltaic cell in association with a component such as solar panel 100. As illustrated by the three optional locations and configurations shown by dotted lines (102, 102', and 102"), a photovoltaic cell can comprise a thin layer in contact with, and optionally adhered to, an external surface (as shown 102), and/or an internal surface (as shown 102'), and/or may be contained within the structure of the panel (as shown 102"). As explained in more detail below in the context of the description of certain preferred photovoltaic cells for use in certain embodiments of the invention, certain of the photovoltaic cells can comprise thin, flexible films capable of being placed in contact with, and optionally adhered to, at least a portion of a support member, such as panel 100 and/or capable of being laminated between, or otherwise contained within, the cross-section of a support member, such as panel 100. In certain embodiments, it may be preferable to locate the photovoltaic cell layer as illustrated in 102", for example such that it is laminated between two transparent support layers (e.g. layers constructed of a transparent or translucent material, such as glass or certain polymeric substances), in order to protect the photovoltaic cell layer from damage. In certain embodiments, a single photovoltaic cell is coextensive with most or essentially all of the surface area, upon which light is incident, of the solar panel article 100, while in other embodiments, for example as illustrated in FIG. 3B and described below, the solar panel article can comprise a plurality of photovoltaic cell regions separated by, optionally transparent, regions of the panel that do not comprise a photovoltaic cell. In the embodiment illustrated in FIG. IB, solar panels 100 comprising photovoltaic cells 102 and/or 102' and/or 102" are assembled into a structure comprising an enclosure, e.g. a greenhouse as illustrated, which contains photosynthetic organisms therein, such as plants 104. In such a greenhouse embodiment, some, and optionally all, of the walls and roof panels of the greenhouse could comprise solar panels that are at least partially transparent to light of at least one wavelength capable of driving photosynthesis in plants 104, and in certain embodiments, photovoltaic cells 102 and/or 102' and/or 102" are at least partially transparent to light of at least one wavelength capable of driving photosynthesis in plants 104. In certain embodiments, a solar panel article 100, at least the portion of which comprises photovoltaic cell(s) 102 and/or 102' and/or 102" can be assembled into or configured as a flexible sheet able to be roll-up and deployed by unrolling. In certain embodiments, such solar panel article could be configured as a type of or substitute for "shade-cloth" typically used in greenhouses to shade plants from direct sunlight to prevent burning. Such shade cloth may be mounted and/or positioned within the greenhouse so that it is suspended in a horizontal orientation parallel to the floor at a level above the tops of the plants. Alternatively, the shade cloth may be mounted and/or positioned within the greenhouse in a variety of other ways, for example, suspended at an angle so that it is substantially parallel an adjacent to one or more roof panels, wall panels, etc. In other embodiments, such solar panel article could be configured as a type of or substitute for a shade, awning, etc. for use in a building/dwelling place. In an example where article 100 comprises shade-cloth for use in a greenhouse, advantageously, various electrical components utilized in the greenhouse, for example, fans, water pumps, motor(s) configured to deploy and/or roll-up the inventive photovoltaic "shade cloth," etc. can comprise direct current (D.C.)-powered motors, so that the curcent generated by the photovoltaic cells (e.g. 102 and/or 102' and/or 102") may be fed directly to the motors so as to avoid losses that typically are incuned during inversion of D.C. to alternating current (A.C.). Such use of D.C. produced by the photovoltaic cells for powering various motors, etc. in the greenhouse, or other building or dwelling place utilizing the above-described solar panel article 100, may increase the power usage efficiency, when compared to A.C. motors, by at least about 5%- 30%. In certain embodiments, a solar panel article 100 may be configured so that a substantial portion of and/or substantially the entire surface area of article 100 upon which light or radiation is incident in use is coextensive with one or more photovoltaic cells. In certain such embodiments, solar panel article 100 may be comprised essentially in its entirety of/as a photovoltaic cell. In such embodiments, it is advantageous that a photovoltaic cell that is at least partially transparent to at least one wavelength of light and/or radiation capable of driving photosynthesis and/or at least one wavelength of infrared radiation, depending on the specific application, such as those described in more detail below, is utilized. In certain embodiments, for example, for certain embodiments in which a solar panel article 100 comprises greenhouse "shade-cloth," window or skylight/roof panel, window shade, etc. configured to admit light to an enclosure/building, etc. it may be desirable or advantageous to configure solar panel 100 as illustrated in FIG. 3B. Referring to FIG. 3B, solar panel 100 comprises a plurality of regions 350 configured as stripes comprising photovoltaic cells 102 and/or 102' and/or 102". Regions of solar panel 100 not comprising a photovoltaic cell, e.g., regions 352 and 354, in certain embodiments, may be partially or substantially transparent to light/radiation of a desired wavelength. In certain embodiments, regions 352 and 354 may be configured to have different light/radiation transmission profiles than photovoltaic cell containing regions 350. For example, regions 352 and/or 354 may be constructed to be more or less transparent than regions 350 to a particular wavelength(s), creating a desirable pattern of shading and/or imparting a desirable color to the light passing through solar panel 100 and filling, for example, an enclosure or room thereof. For example, in certain embodiments, regions 352 and/or 354 not containing photovoltaic cells may be constructed of a material that is more transparent to certain selected wavelengths than are the regions 350 comprising the photovoltaic cells. In certain embodiments, photovoltaic cells 102 and/or 102' and/or 102" utilized according to the invention can comprise a dye-sensitized thin-film photovoltaic cell, (e.g., as illustrated in FIG. 3A) having, for example, light absorption and transmission properties as illustrated in FIG. 5. In such embodiments, incident light passing through the photovoltaic cell will tend to have imparted to it a color indicative of absorption characteristics of the particular dye utilized in the photovoltaic cell. In certain embodiments, for example, when the solar panel article 100 is utilized as, for example, a shade, window/roof/skylight panel, or other article configured to transmit light into, for example, an enclosure or room thereof, such coloration of the transmitted light may not be desirable. The light-color shifting phenomena can be, at least partially, mitigated by configuring solar panel 100 as illustrated, for example, in FIG. 3B, wherein only a portion of the surface area upon which light is incident comprises photovoltaic cells 102 and/or 102' and/or 102". By configuring solar panel 100 to include sufficient surface area in regions 352 and 354, which can be configured and constructed from materials which do not appreciably change the color of visible light transmitted therethrough, any color change effected by light passing through the photovoltaic cells can be at least partially mitigated. In certain embodiments, such as illustrated in FIG. 3B, wherein photovoltaic cell comprising regions 350 are configured as stripes, to reduce the tendency of the photovoltaic cell stripes to create a striped shading pattern upon surfaces onto which light passing through the solar panel 100 impinges, the width of photovoltaic cell regions 350 and their spacing (i.e., the width of regions 352) can be selected such that a desirable level of dispersion of the light is created, thereby reducing any striped shading effect. The particular dimensions of the width of the photovoltaic cell regions 350 and non-photovoltaic cell regions 352 to effect a desirable degree of dispersion will depend upon the particular application and may be determined readily by those of ordinary skill in the art of optics. As suggested above, the width of the photovoltaic cell comprising regions 350 of solar panel article 100 illustrated in FIG. 3B and the spacing of these regions will depend upon the particular application and the desired properties of the light transmission through the solar panel article. In certain, exemplary, embodiments, photovoltaic cell comprising stripes 350 are of essentially uniform width. As previously noted, in certain embodiments, solar panel article 100 may be configured as a film, sheet, or layer, which may be flexible. In certain embodiments, the surface area of article 100 comprising regions 352, and 354 not comprising a photovoltaic cell comprise about three-fourths of the total surface area of the article upon which light/radiation is incident in use, in other embodiments about half of the total surface area, in other embodiments about one-third of the total surface area, and in other embodiments about one-fourth of the total surface area. For example, in one set of embodiments, such as for embodiments wherein solar panel article 100 comprises a shade- cloth-like material for use in a greenhouse, photovoltaic cell comprising regions 350 each have a width of about 10 mm and are separated by a plurality of photovoltaic cell-free regions 352 each having a width of about 5 mm. In another embodiment, photovoltaic cell comprising regions 350 may be 5 mm in width and photovoltaic cell-free regions 352 may also be 5 mm in width. In yet another embodiment, photovoltaic cell comprising regions 350 are 15 mm in width, while photovoltaic cell-free regions 352 are 5 mm in width. While solar panel article 100 illustrated in FIG. 3B comprises a plurality of photovoltaic cell comprising regions 350 configured as stripes, in other embodiments where a solar panel article is configured to include both regions comprising photovoltaic cells and regions not comprising photovoltaic cells, the photovoltaic cell comprising regions may be shaped, positioned, and configured differently than illustrated. For example, in an alternative embodiment, the photovoltaic cell comprising regions may be configured in the shape of circles, squares, ellipses, spirals, etc. and positioned/patterned on and/or in a substrate comprising solar panel article 100 in an extremely wide variety of ways; all of which may be within the scope of the present invention. The size of the greenhouse may be selected based upon the needs of a particular application. For example, in certain embodiments, greenhouse 120 may be of sufficient size to permit entry of one or more people, for example, through door 122. In alternative embodiments, greenhouse 120 may be smaller, for example, the size of a window box or even smaller, and may be configured to be contained within, on, or otherwise associated with, a building or other structure. In yet alternative embodiments, structure 120, may comprise a small terrarium for containing plants and/or other photosynthetic organisms. In one particular embodiment, structure 120 comprises a terrarium or other small photosynthetic organism-containing structure configured to be utilized in space applications, for example, as a container for photosynthetic organisms configured for facilitating CO₂ mitigation and electrical production within a spacecraft, space station, or other sealed environmental chamber housing humans and/or other animals. FIG. 1C illustrates the use of photovoltaic cells, according to the invention, in the context of providing a means for generating electricity from solar energy in a "green building" 123 comprising therein, and/or thereon, photosynthetic organisms, such as plants 104, for use in converting C0₂ into O₂ in building air. While, in FIG. 1C, each of the illustrated plurality of possible configurations is shown as being part of a single green building 123, it should be understood that, in reality, one, several, all, or any combination of the configurations illustrated in FIG. 1C may be used advantageously to promote efficient production of electricity from solar energy and purification of air within a "green building" or other structure for housing humans and/or other animals according to the invention. In a first embodiment, a photosynthetic organism 104 can be contained within a terrarium/greenhouse structure such as shown as 120 in FIG. IB. Such a terrarium or small greenhouse for containing plants can be located either within (location 124) building 123, or associated (location 126) with an external surface of the building, such as roof 128. In an alternative embodiment, a photovoltaic cell 102 and/or 102' and/or 102" can comprise at least a portion of a window 130 of building 123. In yet another embodiment, photovoltaic cell 102 and/or 1O2' and/or 102" can comprise at least a portion of a solar panel or screen 132 positioned adjacent to an external surface 134 of a conventional window (as illustrated) or, alternatively, adjacent to an internal surface of such window (not shown). In yet other alternative embodiments, particularly those in which a photovoltaic cell comprises a flexible film configuration, the photovoltaic cell 102 and/or 102' and/or 102" can be incorporated within and/or on a surface of a window shade 136 or horizontal 138 or vertical 140 window blinds. In certain such applications, a solar panel or screen 132 or 134 or window shade 136 may advantageously be configured as illustrated in FIG. 3B and discussed above. Refening to FIGs. ID and IE, a solar water heating apparatus and system 150 is illustrated to exemplify one embodiment of an apparatus or structure comprising a solar thermal energy collection device and a photovoltaic cell, according to the invention. In the illustrated embodiment, solar water heating system 150 includes a solar thermal energy collection device 152, which comprises, in the present embodiment, a flat-plate solar collector and heat exchanger. It should be understood that while, in the illustrated embodiment, solar thermal energy collection device 152 comprises a flat-plate collector and heat exchanger, in alternative embodiments, the solar thermal energy collection device could be configured differently and/or replaced with in a wide variety of other known and commercially-available solar thermal energy collection devices, many of which are described and illustrated at the U.S. Department of Energy's Energy Efficiency and Renewable Energy websites (e.g. eere.energy.gov/consumerinfo; eere.energy.gov/solar/solar_heating.html; and eere.energy.gov/RE/solar.html — each address preceded by "www." ). The internal configuration of flat-plate solar thermal energy collection device 152 is illustrated in more detail in the partially cut-away view shown in FIG. IE. Flat-plate collector 152 comprises a solar panel article 100, which can be configured similarly to other solar panel articles described previously and illustrated, for example, in FIGs. 1 A or 3B. One or more photovoltaic cells positioned and configured with respect to panel 100 as illustrated as 102 and/or 102' and/or 102" can be coextensive with at least a portion of solar panel article 100 upon which solar radiation is incident in use. As discussed previously, for the present application, solar panel article 100 should be at least partially transparent to at least one wavelength of infrared radiation, and in certain embodiments, photovoltaic cell(s) 102 and/or 102' and/or 102" may also be of a type that is at least partially transparent to at least one wavelength of infrared radiation. As illustrated in FIG. IE, solar panel article 100 comprises an outer, illuminated, surface of an enclosure 154 containing a plurality of flow tubes 156, through which a heat exchange medium flows during operation. In certain embodiments, interior surface 156 of enclosure 154 may be configured as a solar energy absorber plate, which is comprised of and/or coated with a dark-colored heat absorbing material. Alternatively, or in addition to absorber plate 157, at least a portion of the outer surface of flow tubes 156 may be coated with a dark heat absorbent material. In certain embodiments, it can be advantageous for enclosure 154 to be insulated to prevent heat loss there from and/or evacuated and maintained under vacuum. In the illustrated embodiment, solar water heating system 150 comprises a closed-loop solar heat exchanger system, comprising, as a portion thereof, solar thermal energy collection device 152. In operation, a heat exchange fluid, for example, an anti-freeze fluid such as propylene glycol or a propylene glycol/water mixture may be contained in closed flow loop 158 and can made to flow through flow tubes 156 contained in enclosure 154 of solar thermal energy collection device 152. In certain embodiments, liquid circulation through closed flow loop 158 may be effected or assisted by a pump 160, which, advantageously, can be powered via electricity generated by photovoltaic cell(s) 102 and/or 102' and/or 102". In certain embodiments, circulation pump 160 comprises a D.C. motor for improved electrical utilization efficiency. Heat exchange fluid contained in closed flow loop 158 that has been heated by passing through solar thermal energy collection device 152 flowed through a heat exchange coil 162 contained within water heater/storage tank 164. In alternative embodiments, especially where heat exchange fluid contained within solar thermal energy device 152 is not expected to be exposed to temperatures capable of freezing water during use, instead of utilizing a closed flow loop 158 containing an anti-freeze media, water 166 contained in tank 164 could be pumped through solar energy collection device 152 to heat it directly and/or the water storage tank itself could be located inside solar energy collection device 152 and the illustrated flow tubes 156 could be eliminated. In yet other embodiments, the heat exchange fluid circulated through the solar thermal energy collection device may not be a liquid but, rather, may be a gas, such as air. In such an embodiment, solar thermal energy collection device 152 may be utilized as part of a passive or forced air convective heating system utilized for, for example, heating the air in a home, or other building or dwelling place. While FIG. ID illustrates one exemplary configuration of utilizing a solar thermal energy collection device in combination with an article 100 comprising a photovoltaic cell(s), it will be readily apparent to the skilled artisan that a wide variety of other configurations are possible. For example, just to mention a few, a solar heating apparatus or system comprising an article comprising a photovoltaic cell, wherein the article is at least partially transparent to solar radiation, and a solar thermal energy collection device, wherein the article is positioned between the solar thermal energy collection device and a source of solar radiation so that at least a portion of the solar radiation reaching the solar thermal energy collection device passes through the article, could be configured in a wide variety of other ways and utilized for a wide variety of other solar heating purposes. For example, the solar thermal energy collection could be configured to comprise an outside wall of a building or enclosure covered by a dark sheet material or coating, such as a dark sheet metal material, acting as a solar heat collector, wherein a article 100 of the invention comprises a film, layer, sheet, coating, etc. positioned between the absorber material and the sun. In certain such embodiments, the dark sheet material collector may be configured to heat outside air, which is then sucked into the building's ventilation system through, for example, perforations in the collector. In yet another exemplary embodiment, the solar thermal energy collection device may comprise a batch heater configured, for example, as an insulated tank painted black on the outside and mounted so that it is exposed to the sun. In such an embodiment, article 100 could comprise a film, sheet, coating, etc. applied to the outside of such a tank in positioned between the black, or dark-colored coating and the sun, and/or could comprise a separate stand-alone solar panel, e.g. as illustrated in FIG. 1 A and FIG. 2A, positioned with respect to the tank so that solar radiation impinging on the tank passes through the solar panel. In certain such embodiments, such a batch heater could contain water or other fluid desired to be heated and, if desired, may include plunibing connections, pumps, etc. enabling hot water, other fluid to be removed fonn the tank, once heated, and colder water, or other fluid, to be supplied to the tank as needed. FIGs. 2 A and 2B illustrate exemplary embodiments of inventive apparatuses of comprising a photobioreactor 199 containing a liquid medium 201 therein comprising at least one species of photosynthetic organisms. At least a portion of the photobioreactor, 199, such as hypotenuse light tube 203 , is configured to transmit light capable of driving photosynthesis to the photosynthetic organisms. The photobioreactor apparatus 200 further comprises one or more photovoltaic cells (e.g. 102 and/or 102' and/or 102") that are at least partially transparent to light of at least one wavelength capable of driving photosynthesis and that are configured and positioned with respect to photobioreactor 199 so as to enable such photovoltaic cells to transmit light capable of driving photosynthesis to the photosynthetic organisms within the photobioreactor. As mentioned previously, a wide variety of photobioreactor configurations are amenable to the inventive inclusion of a transparent or semi-transparent photovoltaic cell in association therewith, according to the invention, and the illustrated embodiment of a triangularly-arranged tubular photobioreactor 199 is merely a single example. The general design configuration, operating principals, materials of construction, etc. of the basic photobioreactor 199 illustrated in FIG. 2 A is described in much greater detail in Applicant's International Application publication No. WO 03/094598 and Applicant's U.S. Patent Application Publication No. US-2005-0064577-A1, to which the interested reader is referred. The apparatus 200 of^" FIG. 2A illustrates several alternative configurations and locations for placement of photovoltaic cells, according to the invention. In one embodiment, photobioreactor apparatus 2O0 comprises a photovoltaic cell layer 102" comprising at least a portion of a solar panel 100 that is configured and positioned as a screen or shade that is not in physical contact with any portion of the photobioreactor 199 that is configured to transmit light to the photosynthetic organisms (e.g. light tube 203 of photobioreactor 199). In the illustrated embodiment, optional solar panel 100 comprises a photovoltaic cell layer 102" embedded within the structure of panel 100 or, alternatively, laminated between two transparent, or partially transparent support layers 202, 204. As illustrated, and as described in more detail below, photovoltaic cell 102" of solar panel 100 can be connected in electrical communication (e.g. via wires 210) with at least one component of the photobioreactor apparatus 200 powered by electricity (e.g. liquid pump 212) and/or with at least one electrical storage component, such as a battery 214 and/or capacitor, etc., that is in electrical communication with at least one component (e.g. computer control system 216) of the photobioreactor apparatus 200 that is powered by electricity. In addition to, or alternatively, a photovoltaic cell(s) may be integrated within or provided in contact with a portion of the photobioreactor 199 itself that is configured to transmit light capable of driving photosynthesis to> the photosynthetic organisms, for example light tube 203 as illustrated. As shown most clearly in FIG. 2B, in certain embodiments, light tube 203 can be configured to include: a photovoltaic cell 102 comprising at least a portion of a film at least partially covering the external, light-facing surface 218 of light tube 203; and/or a photovoltaic cell 102' comprising at least a portion of a film at least partially covering an internal surface 220 of light tube 203. In addition, or alternatively, a photovoltaic cell, such as photovoltaic cell 102", can be integrated into the wall of light tube 203 in a fashion similar to that described previously for solar panel 100 of FIG. 2 A. Because each of the photovoltaic cell layer positions illustrated in FIG. 2B are potentially optional and may be provided together or individually in any one of the illustrated locations, each of the layers, as illustrated in FIG. 2B, is shown in dashed lines. ° As explained in greater detail in Applicant's International Patent Publication No. WO 03/094598, in certain embodiments, photobioreactor apparatuses, such as photobioreactor apparatus 200 of FIG. 2 A, can comprise part of an overall system for mitigation of pollutants contained in gas streams. Accordingly, as illustrated in FIG. 2A and as explained in more detail in Applicant's International Patent Publication No. WO 03/094598, in certain embodiments, photobioreactor apparatus 200 can Toe connected in fluid communication with a source of combustion gas 230 derived from a power generating apparatus and/or an incinerator 232. In each of the above embodiments wherein a photovoltaic cell is provided in combination with a support structure for forming a. solar panel or a tube or other light- transparent portion of a photobioreactor or solar panel, such support materials may be constructed from a wide variety of transparent or translucent materials having sufficient transparency to light at wavelengths suitable for driving phiotosynthesis to permit growth of photosynthetic organisms exposed to such light, at intensities expected to be available for a particular application, incident upon the material. Some examples include, but are not limited to, glass, and a variety of transparent or translucent polymeric materials, such as polyethylenes, polypropylenes, polyethylene terepthalates, polyacrylates, polyvinylchlorides, polystyrenes, polycarbonates, etc. Alternatively, such materials may also be formed from resin-supported fiberglass. The above-described inventive apparatuses and systems for simultaneously facilitating photosynthesis by photosynthetic organisms, and/or heat exchange and/or heat collection with a solar thermal energy collection device, and generating electricity via photovoltaic cells enable and are amenable to the practice of methods of use also provided according to the invention. For example, the invention, in certain aspects, provides a method for generating electricity and promoting growth and photosynthesis by a photosynthetic organism that comprises positioning of an article comprising one or more photovoltaic cells, which are optionally at least partially transparent to light of at least one wavelength capable of driving photosynthesis, between the photosynthetic organism and a source of light capable of driving photosynthesis, so that at least a portion of the light reaching the photosynthetic organism passes through the article and/or photovoltaic cell. Certain such methods entail directing the light from the source of light, such as the sun, onto the photovoltaic cell, or a support structure/article carrying the photovoltaic cell, so that at least a portion of the light is absorbed by the photovoltaic cell, thereby generating an electrical energy within the photovoltaic cell, and so that at least a portion of the light is transmitted through the photovoltaic cell, so as to impinge upon the photosynthetic- organism, thereby driving photosynthesis in the photosynthetic organism. As described above in the context of FIGs. 2A and 2B, in certain embodiments, the method can be practiced employing a photobioreactor apparatus containing a plurality of photosynthetic organisms therein, such as algae. Moreover, in certain forms of such embodiments, t e photobioreactor apparatus can be advantageously operated in such a way so as to mitigate environmental pollutants from a gas stream, e.g. via introducing the gas stream to be treated into the photobioreactor and at least partially removing from the gas with the photobioreactor environmental pollutant such CO₂ and/or NO_x. In certain embodiments, the source of such a gas stream can be a power generating apparatus and/or incinerator facility. The invention, in certain aspects, also provides a method for generating electricity and promoting solar thermal energy collection that comprises positioning of an article comprising one or more photovoltaic cells, which are optionally at least partially transparent to infrared radiation, between a solar thermal energy collection device and a source of infrared radiation, so that at least a portion of the radiation reaching the solar thermal energy collection device passes through the article and/or photovoltaic cell. Certain such methods entail directing radiation comprising infrared radiation from its source, such as the sun, onto the photovoltaic cell, or a support structure/article carrying the photovoltaic cell, so that at least a portion of the incident radiation is absorbed by the photovoltaic cell, thereby generating an electrical energy within the photovoltaic cell, and so that at least a portion of the radiation is transmitted through the photovoltaic cell, so as to impinge upon the solar thermal energy collection device, e.g. as described above in the context of FIG. ID. In addition, certain aspects of the invention involve facilitating the generation of electricity and photosynthesis and/or the generation of electricity and the operation of a solar thermal energy collection device by providing an article comprising a photovoltaic cell that is, optionally, at least partially transparent to light of at least one wavelength capable of driving photosynthesis and/or that is at least partially transparent to at least one wavelength of infrared radiation. As used herein in the above context, "facilitating" or "promoting" includes all methods of doing business including methods of^" education, industrial and other professional instruction, energy industry activity, construction industry activity, and any advertising or other promotional activity including written, oral, and electronic communication of any form associated with the generation of electricity via photovoltaic cells, the construction and operation of "green buildings," the operation of solar thermal energy collection devices, and the use of photobioreactors for pollutant mitigation and/or algal growth. In certain embodiments, the inventive methods of promoting or facilitating the generation of electricity and photosynthesis and/or the operation of a solar thermal energy collection device can further comprise providing instructions directing a user to position a photovoltaic cell between a photosynthetic organism and/or a solar thermal energy collection device and a source of light/radiation capable of driving photosynthesis, and/or comprising infrared radiation, so that at least a portion of the light reaching the photosynthetic organism and/or solar energy collection device from the source of light/radiation passes through article comprising the photovoltaic cell and/or the photovoltaic cell. In certain embodiments, such instructions can form part of a kit also comprising a photovoltaic cell forming a least a portion of a solar panel article that is at least partially transparent to light/radiation of at least one wavelength capable of driving photosynthesis and/or at least one wavelength of infrared radiation. "Instructions" or "directions" can and often do define a component of promotion or facilitation, and typically involve written instructions. Instructions and directions can also include any oral and/or electronic instructions provided in any manner. Photovoltaic technology, in use for many years, was considerably improved by invention of photovoltaic cells employing the incorporation of compatible dye into a particulate semiconductor matrix. This technology, as described in more detail below, can enable the ability to fabricate photovoltaic cells that are very thin and at least partially transparent. Moreover, the selection of appropriate sensitizing dyes can enable the wavelength of light absorbed by the active layers of the photo voltaics for generating electricity to be tunable, based of the absorbance profile of the dye. Appropriate dye selection and fabrication can, according to the invention, result in a photovoltaic cell having an absorbance and light transmission profile over the range of wavelengths between 400 nm - 700 nm permitting sufficient quantities of light of appropriate wavelengths to pass through the photovoltaic cell to enable the transmitted light to support photosynthesis and growth of photosynthetic microorganisms, such as plants and algae. Such photovoltaic cell can, in certain embodiments, have a radiation transmission profile over the range of wavelengths between 700 nm - 1 x 10⁶ nm permitting sufficient quantities of infrared radiation of appropriate wavelengths to pass through the photovoltaic cell to enable the transmitted radiation to be utilized for heating/heat exchange purposes, e.g. by a solar thermal energy collection device. Certain embodiments of the dye-sensitized technology involve use of nanometer-scale crystals of semiconductor materials, for example metal oxides such as TiO₂ semiconductor, which are coated with light-absorbing dye, typically a monolayer of such dye, and which are embedded in an electrolyte between front and tack electrical contacts or conducting layers. Photons in light are absorbed by the dye and result in exciting the dye to an excited state, which results in release of electrons from the dye to the semiconductor (see FIG. 6 and associated discussion as well as the patents and references directed to this technology referred to and incorporated by reference previously and below for more detail). Photovoltaic cells of the type described above that are usable, potentially usable, or could be adapted to be usable in the context of the present inventions are manufactured by, and/or described in published literature by, for example, Solaronix SA, Aubonne, Switzerland and Konarka Technologies, Inc., Lowell, MA, USA. Other companies patents or published patent applications describing photovoltaic technology,, which may be suitable in the context of the present invention, include Nanosolar, Inc., Palo Λlto, CA (e.g. U.S. Patent No. 6,852,920, and NANOS YS, Inc., Palo Alto, CA (e.g. U .S. Patent Application Publication No. US 2004/0118448). Konarka Technology's photovoltaic cell designs and films may be well suited for practicing many embodiments of the present invention because of their flexibility and ability to be formed into a variety of shapes and sizies. The fabrication processes utilized by Konarka allows them to fabricate photovoltaic cells on lower cost, flexible materials, rather than on glass or silicon, which are used in traditional photovoltaic cells. This flexibility can allow such photovoltaic films to be used as coatings on or incorporated into panels and substrates that are curved, for example photobioreactor light tube 203 illustrated in FIGs. 2 A and 2B. Moreover, with low-cost raw materials and relatively low-cost manufacturing technology and processes, deposited photovoltaic thin films have the potential to provide more than a 50 percent reduction in cost relative to traditional crystalline photovoltaic cell modules. Dye-sensitized photovoltaic cells can also be efficient across a wider spectrum of light than many conventional photovoltaics, making them useful both indoors and out. Another advantage of utilizing the above-mentioned dye-sensitized photovoltaic cells in the context of the present inventiorxs is that the wavelengths most strongly absorbed to produce electrical energy can be controlled by the coating procedure and dye used, and may be tailored to fit the absorbance maxima (Table 2) of potentially any photosynthetic organism. In this way, it may be possible, according to certain embodiments of the invention, to achieve a solar efficiency (solar to D>.C.) of at least about 5% coupled with a solar efficiency in driving photosynthesis (solar to biomass) of at least about 10% in a combined system as described above in the context of FIGs 1A-1C, 2A-2B. In addition, light wavelength control might also help in controlling the bio-population that grows under the photovoltaic cells to encourage growth of desirable organisms having absorbance maxima in regions where there is less absorbance by the photovoltaic cell and to discourage growth of undesirable organisms having absorbance maxima in regions where there is more absorbance by the photovoltaic cell. Advantageously, certain embodiments of the present inventions can enable simultaneous generation (on the same footprint) of electricity and biomass for enhanced CO and NO_x mitigation, organic nitrogen control, and water recycling. Generated electricity may also be used to supply electricity to hardware, lights, grid (converted to A.C.) etc. Photovoltaic Cells, Films, and Modules Based on Dye-sensitized Titania (TiO? A brief overview and description is presented below of the design, configuration and operating principles of exemplary photovoltaic cells that may be employed in the context of the present invention. The exemplary photovoltaic cell described comprises a thin, flexible dye-sensitized photovoltaic cell as manufactured by Konarka Technologies, Inc. Fabrication process, methods and materials of construction, configuration for use in generating electrical energy to power electrical apparatuses, etc. for these photovoltaic cells have been thoroughly described in one or more of the following patent and published patent applications owned by Konarka Technologies, Inc: U.S. Patent No. 6,706,963; U.S. Patent Application Publication No. US 2003/0056821; U.S. Patent Application Publication No. US 2004/0025934; U.S. Patent Application Publication No. US 2003/0188777; U.S. Patent Application Publication No. US 2003/0189402; U.S. Patent Application Publication No. US 2003/0192583; U.S. Patent Application Publication No. US 2004/0031520; U.S. Patent Application Publication No. US 2003/0192585; U.S. Patent Application Publication No. US 2004/0025933; U.S. Patent Application Publication No. US 2003/0230337; U.S. Patent Application Publication No. US 2003/0192584, and U.S. Patent Application Publication NJo. US 2005/0045851, each of which is incorporated herein by reference. The thin-film photovoltaic cell technology described in the above references enables production of photovoltaic cells that can be lightweight, flexible and nearly unbreakable. For example, such photovoltaic modules can be cut and punctured with very little effect on performance. This combination of attributes enables new applications for photovoltaics, with new form factors including, for example, molded plastics with complex curved surfaces. Referring to FIG. 3A, an individual photovoltaic cell 300 can comprises one layer of photo-active material 302 sandwiched between two transparent electrodes 304, 306 and transparent flexible substrates 308, 310 - for example indium tin oxide (ITO)-coated polyethylene terephthalate (PET). If the active layer 302 is approximately 4 - 6 μm thick or less, then it can be transparent enough to allow certain wavelengths of light/radiation, which can be selectable depending on the nature of the sensitizing dye utilized (see FIG. 5 and

Table 2), to pass through it sufficiently to permit the light passing through to support growth and photosynthesis by photosynthetic organisms able to grow when exposed to such wavelengths and/or to be useful for solar thermal energy collection applications. The cell can be made, in one exemplary embodiment, by first coating and drying a 5 μm layer of TiO suspension from water. The particles are heated to about 110 degrees C to interconnect the nanoparticles forming a hard, sponge-like strαcture; this process is referred to as low temperature sintering and is described in U.S. Patent Application Publication No. US 2003/0056821. An SEM (FIG. 4) shows the interconnected particles after sintering. The image clearly shows the interconnection of particles that is desirable for making good electrical contact. This interconnectivity facilitates the ability of photogenerated electrons to escape from the cell and perform work on an external load. Titania itself is not sensitive to visible radiation and, in analogy to silver halide photographic emulsions, dyes that absorb light in the visible region of the spectrum are added to the surface of the titania particles to sensitize them. The primary function of such dye is to sensitize titania to visible light by absorbing incident photons and injecting electrons from the excited state of the dye into the band gap of the titania. This phenomenon was first reported by O'Regan and Gratzel at Ecole Polytechnique Federale de Lausanne (EPFL) in the early '90's (see O'Regan and Gratzel 1991). The dyes used for sensitizing the titania are, in certain embodiments, Ru-bipyridyls and can be chosen to based on their having advantageous absorption and redox characteristics for practicing the invention. The ruthenium-based dyes (see, for example Structure I) have been developed by Gratzel , et al., over the last decade (see, Gratzel 2001(a) and Gratzel 2001(b)). Structure I (full chemical name: cis- bis(isothiocyanato)bis(2,2^,-bipyridyl-4,4'-dicarboxylato)-ruthenium (II) - designated "N3" herein and available from Solaronix SA, Aubonne, Switzerland) as described in more detail below and as illustrated in FIG. 5, has absorption characteristics - relatively low absorbance above 600 nm and an absorbance minimum between about 450- 500 nm - that are well tuned to facilitate transmission of infrared radiation and light at wavelengths useful for driving photosynthesis - see Table 2. Other ruthenium-based dyes that have similarly advantageous absorbance characteristics (see FIG. 5) include: -bis(isothiocyanato)(2,2'-bipyridyl-4,4'- dicarboxylato)(2,2'-bipyridyl-4,4'-di-nonyl) ruthenium (II) - designated "Z907" herein and available from Solaronix SA, Aubonne, Switzerland and ct₁s^,-bis isothiocyanato)bis(2,2'- bipyridyl-4,4'-dicarboxylato)-ruthenium (II) bis-tetrabutylammonium - designated "N719" herein and available from Solaronix SA, Aubonne, Switzerland.

N3 : Ru(BipyridyICθθH)₂ (N=C=S)₂ Structure I

Although these dyes absorb across the entire visible region of the solar spectrum, there are areas in the spectrum that are only weakly absorbed (see FIG. 5). These areas can be adjusted by changing the molecular structure of the ligands attached to the Ru or by using another class of dyes. Of particular note for the present inventions is the deep minimum in the absorption spectrum of the dyes in the 450 - 500 nm region. This region represents the wavelengths used by many species of algae for photosynthesis. An electrolyte containing an iodide/triiodide ( ι7I₃ ^~) redox couple is added to the dyed titania so that it, in certain embodiments, completely fills titania pores and slightly over fills them. The electrolyte acts as a shuttle between the electrode 304 (see FIG. 3A) and the oxidized dye. The counter electrode 306, which can have a thin (~2 nm) layer 311 of a catalyst, such as carbon or Pt ,deposited on its surface, is brought into contact with the electrolyte, laminated and sealed to complete the cell. In summary, the operating mechanism of the dye sensitized solar cell is demonstrated in FIG 6. Light is absorbed by the dye 400 that is chemisorbed to the surface of the titania 402; this produces an excited, oxidized state of the dye. Tne latter injects an electron 404 into the conduction band of the titania semi-conductor which is transported to the transparent electrode 304 that it is coated on. The electron 404' exits the cell and travels through the external circuit 406 to the load 408- in this example a light bulb but it could be a motor or a battery, etc. After doing work, the electron 404" re-enters the cell at the secondary electrode 306 which has a thin layer 311 of catalyst coated on it. Triiodide (I₃ ^") 312 is reduced at the surface of the electrode to iodide (I^") 314. The latter diffuses back to the oxidized dye and reduces it back to its ground or original state thus completing the cycle. While several embodiments of the invention have been, described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and structures for performing the functions and/or obtaining the results or advantages described herein, and each of such variations, modifications and improvements is deemed to be within the scope of the present invention. More generally, those skilled in the art would readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that actual parameters, dimensions;, materials, and configurations will depend upon specific applications for which the teachings of the present invention are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the invention may be practiced otherwise than as specifically described. The present invention is directed to each individual feature, system, material and/or method described herein. In addition, any combination of two or more such features, systems, materials and/or methods, provided that such features, systems, materials and/or methods are not mutually inconsistent, is included within the scope of the present invention. In the claims (as well as in the specification above), all transitional phrases or phrases of inclusion, such as "comprising," "including," "carrying," "having," "containing," "composed of," "made of," "formed of," "involving" and the like shall be interpreted to be open-ended, i.e. to mean "including but not limited to" and, therefore, encompassing the items listed thereafter and equivalents thereof as well as additional items. Only the transitional phrases or phrases of inclusion "consisting of and "consisting essentially of are to be interpreted as closed or semi-closed phrases, respectively. The indefinite articles "a" and "an," as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean "at least one." The phrase "and/or," as used herein in the specification and in the claims, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in. other cases. Other elements may optionally be present other than the elements specifically identified by the "and/or" clause, whether related or unrelated to those elements specifically identified. Thus, as a non- limiting example, a reference to "A and/or B" can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc. As used herein in the specification, and in the claims, "or" should be understood to have the same meaning as "and/or" as defined above. For example, when separating items in a list, "or" or "and/or" shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of or "exactly one of," will refer to the inclusion of exactly one element of a number or list of elements. In general, the term "or" as used herein shall only be interpreted as indicating exclusive alternatives (i.e. "one or the other but not both") when preceded by terms of exclusivity, such as "either," "one of," "only one of," or "exactly one of." As used herein in the specification and in the claims, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements that the phrase "at least one" refers to, ^whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B," or, equivalently ""at least one of A and/or B") can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc. In cases where the present specification and a document incorporated by reference and/or referred to herein include conflicting disclosure, and/or inconsistent use of terminology, and/or the incorporated/referenced documents use or define terms differently than they are used or defined in the present specification, the present specification shall control.

What is claimed:

Claims

1. An apparatus or structure comprising: an article comprising a photovoltaic cell, the article being at least partially transparent to light of at least one wavelength capable of driving photosynthesis; and a photosynthetic organism capable of undergoing photosynthesis upon exposure to light of at least one wavelength to which the article is at least partially transparent, wherein the article is positioned between the photosynthetic organism and a source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the article.

2. An apparatus or structure as in claim 1, wherein the photovoltaic cell is at least partially transparent to light of at least one wavelength capable of driving photosynthesis, and wherein the article is positioned between the photosynthetic organism and the source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the photovoltaic cell.

3. An apparatus or structure as in claim 1, wherein article is configured as a film, sheet, or layer, and wherein the film, sheet or layer comprises a plurality of regions comprising at least one photovoltaic cell separated by regions of the film, sheet, or layer not comprising a photovoltaic cell.

4. An apparatus or structure as in claim 3, wherein the plurality of regions are arranged in and/or on the film, sheet, or layer as a plurality of stripes.

5. An apparatus or structure as in claim 4, wherein the regions of the film, sheet, or layer not comprising a photovoltaic cell are transparent to light of at least one wavelength capable of driving photosynthesis.

6. An apparatus or structure as in claim 5, wherein the plurality of stripes are essentially uniform in width and are positioned in and/or on the article so that they alternate with a plurality of stripes of essentially uniform width comprising the regions of the film, sheet, or layer not comprising a photovoltaic cell.

7. An apparatus or structure as in claim 5, wherein the surface area of the film, sheet, or layer comprising the regions not comprising a photovoltaic cell comprise about half of the total surface area of the film, sheet, or layer.

8. An apparatus or structure as in claim 6, wherein the surface area of the film, sheet, or layer comprising the regions not comprising a photovoltaic cell comprise about half of the total surface area of the film, sheet, or layer.

9. An apparatus or structure as in claim 5, wherein the surface area of the film, sheet, or layer comprising the regions not comprising a photovoltaic cell comprise about 1/3 of the total surface area of the film, sheet, or layer.

10. An apparatus or structure as in claim 6, wherein the surface area of the film, sheet, or layer comprising the regions not comprising a photovoltaic cell comprise about 1/3 of the total surface area of the film, sheet, or layer.

11. An apparatus or structure as in claim 5, wherein the surface area of the film, sheet, or layer comprising the regions not comprising a photovoltaic cell comprise about 1/4 of the total surface area of the film, sheet, or layer.

12. An apparatus or structure as in claim 6, wherein the surface area of the film, sheet, or layer comprising the regions not comprising a photovoltaic cell comprise about 1/4 of the total surface area of the film, sheet, or layer.

13. An apparatus or structure as in claim 2, wherein the photovoltaic cell is at least partially transparent to light of at least one wavelength between about 400 nm and about 700 nm.

14. An apparatus or structure as in claim 2, wherein the apparatus comprises a plurality of photosynthetic microorganisms and wherein the apparatus or structure further comprises a photobioreactor containing the photosynthetic microorganisms.

15. An apparatus or structure as in claim 14, wherein the photobioreactor contains a liquid medium therein comprising the photosynthetic organisms, and wherein at least a portion of the photobioreactor is configured to transmit light capable of driving photosynthesis to the photosynthetic organisms.

16. An apparatus or structure as in claim 15, wherein the photovoltaic cell comprises at least a portion of a film at least partially covering the portion of the photobioreactor that is configured to transmit light capable of driving photosynthesis to the photosynthetic organisms.

17. An apparatus or structure as in claim 15, wherein the photovoltaic cell is integrated into a wall or tube comprising the portion of the photobioreactor that is configured to transmit light capable of driving photosynthesis to the photosynthetic organisms.

18. An apparatus or structure as in claim 15, wherein the photovoltaic cell comprises at least a portion of a screen or shade that is not in physical contact with the portion of the photobioreactor that is configured to transmit light capable of driving photosynthesis to the photosynthetic organisms.

19. An apparatus or structure as in claim 14, wherein an inlet of the photobioreactor is connected in fluid communication with a source of combustion gas derived from a power generating apparatus and/or an incinerator.

20. An apparatus or structure as in claim 14, wherein the photovoltaic cell is connected in electrical communication with at least one component of the photobioreactor powered by electricity and/or with at least one electrical storage component, such as a battery and/or capacitor, in electrical communication with at least one component of the photobioreactor powered by electricity.

21. An apparatus or structure as in claim 14, wherein the plurality of photosynthetic microorganisms comprise algae.

22. An apparatus or structure as in claim 1, wherein the apparatus or structure comprises an enclosure containing the photosynthetic organism.

23. An apparatus or structure as in claim 22, wherein the enclosure comprises a photobioreactor.

24. An apparatus or structure as in claim 23, wherein the photobioreactor comprises a tubular photobioreactor.

25. An apparatus or structure as in claim 22, wherein the enclosure comprises a building.

26. An apparatus or structure as in claim 25, wherein the photosynthetic organism comprises a plant.

27. An apparatus or structure as in claim 25, wherein the photovoltaic cell comprises at least a portion of a window or roof panel of the building.

28. An apparatus or structure as in claim 25, wherein the photovoltaic cell comprises at least a portion of a window shade or window blinds of the building.

29. An apparatus or structure as in claim 25, wherein the building comprises a greenhouse.

30. An apparatus or structure as in claim 29, wherein the article is configured as shade cloth.

31. An apparatus or structure as in claim 25, wherein the building comprises at least one D.C. powered electrical apparatus in electrical communication with the photovoltaic cell.

32. An apparatus or structure as in claim 22, wherein the enclosure comprises a tenarium.

33. An apparatus comprising : a photobioreactor containing a liquid medium therein comprising at least one species of photosynthetic organisms, at least a portion of the photobioreactor being configured to transmit light capable of driving photosynthesis to the photosynthetic organisms; and an article comprising a photovoltaic cell, the article being configured and positioned with respect to the photobioreactor to transmit light capable of driving photosynthesis to the photosynthetic organisms.

34. An apparatus as in claim 33, wherein the photovoltaic cell is at least partially transparent to light of at least one wavelength capable of driving photosynthesis, and wherein the article is positioned between the photosynthetic organism and the source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the photovoltaic cell.

35. An apparatus as in claim 33, wherein article is configured as a film, sheet, or layer, and wherein the film, sheet, or layer comprises a plurality of regions comprising at least one photovoltaic cell separated by regions of the film, sheet, or layer not comprising a photovoltaic cell.

36. An apparatus as in claim 35, wherein the plurality of regions are arranged in and/or on the film, sheet, or layer as a plurality of stripes.

37. A method comprising an act of: positioning an article that is at least partially transparent to light of at least one wavelength capable of driving photosynthesis and comprising a photovoltaic cell between a photosynthetic organism and a source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the article.

38. A method as in claim 37, further comprising an act of: directing light from the source of light onto the photovoltaic cell.

39. A method as in claim 38, further comprising an act of: absorbing at least a portion of the light with the photovoltaic cell, thereby generating an electrical current with the photovoltaic cell.

40. A method as in claim 39, wherein the photovoltaic cell is at least partially transparent to light of at least one wavelength capable of driving photosynthesis, and wherein in the positioning act, the article is positioned between the photosynthetic organism and the source of light capable of driving photosynthesis so that at least a portion of the light reaching the photosynthetic organism from the source of light passes through the photovoltaic cell.

41. A method as in claim 39, wherein article is configured as a film, sheet, or layer, and wherein the film, sheet, or layer comprises a plurality of regions comprising at least one photovoltaic cell separated by regions of the film, sheet, or layer not comprising a photovoltaic cell.

42. A method as in claim 41, wherein the plurality of regions are arranged in and/or on the film, sheet, or layer as a plurality of stripes.

43. A method as in claim 40, further comprising an act of: transmitting at least a portion of the light through the photovoltaic cell and impinging the portion of the light transmitted through the photovoltaic cell on the photosynthetic organism, thereby driving photosynthesis in the photosynthetic organism.

44. A method as in claim 40, further comprising an act of providing a plurality of photosynthetic organisms that comprise photosynthetic microorganisms in a photobioreactor apparatus.

45. A method as in claim 44, further comprising an act of: introducing a stream of gas to be treated to the photobioreactor; and at least partially removing from the gas with the photobioreactor CO₂ and/or NO_x.

46. A method as in claim 45, wherein the gas introduced in the introducing step comprises combustion gas derived from a power generating apparatus and/or an incinerator.

47. A method comprising: facilitating the generation of electricity and photosynthesis by providing an article comprising a photovoltaic cell, wherein the article is at least partially transparent to light of at least one wavelength capable of driving photosynthesis.

48. A method as in claim 47, wherein the photovoltaic cell is at least partially transparent to light of at least one wavelength capable of driving photosynthesis.

49. An apparatus or structure comprising: an article comprising a photovoltaic cell, the article being at least partially transparent to solar radiation of at least one wavelength; and a solar thennal energy collection device, wherein the article is positioned between the solar thermal energy collection device and a source of solar radiation so that at least a portion of the solar radiation reaching the solar thermal energy collection device passes through the article.

50. An apparatus or structure as in claim 49, wherein the article is at least partially transparent to infrared radiation of at least one wavelength.

51. An apparatus or structure as in claim 50, wherein the photovoltaic cell is at least partially transparent to infrared radiation of at least one wavelength, and wherein the article is positioned between the solar thermal energy collection device and the source of solar radiation so that at least a portion of the solar radiation reaching the solar thermal energy collection device from the source of solar radiation passes through the photovoltaic cell.

52. An apparatus or structure as in claim 49, wherein the solar thermal energy collection device comprises a device configured to heat a fluid contained in and/or flowing the device.

53. An apparatus or structure as in claim 52, wherein the solar thermal energy collection device comprises a solar water heater or component thereof.

54. A method comprising an act of: positioning an article that is at least partially transparent to solar radiation of at least one wavelength and comprising a photovoltaic cell between a solar thermal energy collection device and a source of solar radiation so that at least a portion of the solar radiation reaching the solar thermal energy collection device from the source of solar radiation passes through the article.

55. A method as in claim 54, wherein the article is at least partially transparent to infrared radiation of at least one wavelength.

56. A method as in claim 55, further comprising: absorbing at least a portion of the solar radiation with the photovoltaic cell, thereby generating an electrical cunent with the photovoltaic cell.

57. A method as in claim 56, wherein the photovoltaic cell is at least partially transparent to infrared radiation of at least one wavelength, and wherein in the positioning act, the article is positioned between the solar thermal energy collection device and the source of solar radiation so that at least a portion of the solar radiation reaching the solar thermal energy collection device from the source of solar radiation passes through the photovoltaic cell.

58. A method as in claim 57, further comprising an act of: transmitting at least a portion of the solar radiation comprising the infrared radiation of at least one wavelength through the photovoltaic cell and impinging the portion of the light transmitted through the photovoltaic cell on the solar thermal energy collection device, thereby transferring thermal energy to the thermal energy collection device.

59. A method comprising: facilitating the generation of electricity and the operation of a solar thermal energy collection device by providing an article comprising a photovoltaic cell, wherein the article is at least partially transparent to solar radiation of at least one wavelength.

60. A method as in claim 59, wherein the article is at least partially transparent to infrared radiation of at least one wavelength.

61. A method as in claim 60, wherein the photovoltaic cell is at least partially transparent to infrared radiation of at least one wavelength.