# US 2014/0153122 A1 · Concentrating solar power apparatus having mirror coating and anti-soiling coating > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153122 A1 - Document ID: US20140153122A1 - Status: Published application - Kind: A1 - Application number: 13/690,035 - Filed: 2012-11-30 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Guardian Industries Corp. - Applicants: Guardian Industries Corp. - Inventors: Jiangping WANG; Rudolph H. PETRMICHL - Web page: https://patentgrep.com/patent/US20140153122A1 ## CPC - F24S 23/82: {characterised by the material or the construction of the reflector} - F24S 23/74: with trough-shaped or cylindro-parabolic reflective surfaces - G02B 1/116: including electrically conducting layers - G02B 1/18: Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films (G02B1/16 takes precedence) - G02B 5/0858: {the reflecting layers comprising a single metallic layer with one or more dielectric layers} - G02B 5/10: with curved faces - G02B 27/0006: {with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation (G02B1/18 takes precedence; cleaning in general B08B)} - Y02E 10/40: Solar thermal energy, e.g. solar towers - F24S: SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS (for producing mechanical power from solar energy F03G6/00) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract An anti-soiling coating is provided in a solar collector apparatus. In certain example embodiments, an anti-soiling coating and a mirror coating are provided on opposite sides of a glass substrate of a mirror structure. In certain example embodiments, the anti-soiling coating may be provided on the first/front surface of a solar panel or solar mirror used in a solar collector field. For example, the anti-soiling coating may be provided on the front/first surface of a parabolic trough or dish reflector/mirror for use in a concentrating solar power apparatus. The provision of the anti-soiling coating can protect the maximum output power of the solar collector from dust and/or environmental pollution such as dirt. ## Claims ### Claim 1 A concentrating solar power apparatus comprising: a mirror for reflecting incident radiation from the sun to a common location in order to cause energy to be collected and/or generated due to radiation from the sun that is reflected by the mirror and is incident at the common location; wherein the mirror comprises a glass substrate, an anti-soiling coating, and a mirror coating, and wherein the anti-soiling coating and the mirror coating are located on opposite sides of the glass substrate. ### Claim 2 (depends on 1) The concentrating solar power apparatus of claim 1, wherein the common location comprises at least one solar panel. ### Claim 3 (depends on 1) The concentrating solar power apparatus of claim 1, wherein the common location comprises a liquid to be heated so that the reflected sunlight heats the liquid and energy is collected from the heat and/or steam generated by the heated liquid. ### Claim 4 (depends on 1) The concentrating solar power apparatus of claim 1, wherein the mirror has a substantially parabolic shape. ### Claim 5 (depends on 1) The concentrating solar power apparatus of claim 1, wherein the mirror has a solar reflectance of at least 85%. ### Claim 6 (depends on 1) The concentrating solar power apparatus of claim 1, wherein the mirror has a solar reflectance of at least 88%. ### Claim 7 (depends on 1) The concentrating solar power apparatus of claim 1, wherein a reflective layer of the mirror coating comprises silver. ### Claim 8 (depends on 7) The concentrating solar power apparatus of claim 7, wherein the reflective layer of the mirror coating comprising silver is sandwiched between first and second dielectric layers. ### Claim 9 (depends on 1) The concentrating solar power apparatus of claim 1, wherein a reflective layer of the mirror coating comprises aluminum. ### Claim 10 (depends on 9) The concentrating solar power apparatus of claim 9, wherein the reflective layer of the mirror coating comprising aluminum is sandwiched between first and second dielectric layers. ### Claim 11 (depends on 1) The concentrating solar power apparatus of claim 1, wherein the glass substrate comprises soda lime silica glass and has a thickness of from 1.0 to 6.0 mm. ### Claim 12 (depends on 1) The concentrating solar power apparatus of claim 1, wherein the anti-soiling coating comprises a transparent conductive layer comprising ITO located between a first layer comprising silicon oxynitride and a second layer comprising an oxide and/or nitride of silicon, wherein the first layer comprising silicon oxynitride is located between at least the glass substrate and the transparent conductive layer comprising ITO. ### Claim 13 (depends on 12) The concentrating solar power apparatus of claim 12, wherein the first layer comprising silicon oxynitride is located between and directly contacting the glass substrate and the transparent conductive layer comprising ITO. ### Claim 14 (depends on 13) The concentrating solar power apparatus of claim 13, wherein the anti-soiling coating consists essentially of the transparent conductive layer comprising ITO, the first layer comprising silicon oxynitride, and the second layer comprising an oxide and/or nitride of silicon. ### Claim 15 (depends on 12) The concentrating solar power apparatus of claim 12, wherein the transparent conductive layer comprising ITO is from about 5-150 nm thick. ### Claim 16 (depends on 12) The concentrating solar power apparatus of claim 12, wherein the transparent conductive layer comprising ITO is from about 5-50 nm thick. ### Claim 17 (depends on 12) The concentrating solar power apparatus of claim 12, wherein the transparent conductive layer comprising ITO is from about 5-20 nm thick. ### Claim 18 (depends on 12) The concentrating solar power apparatus of claim 12, wherein the transparent conductive layer comprising ITO has a sheet resistance (Rs) of from about 200-2,000 ohms/square. ### Claim 19 (depends on 12) The concentrating solar power apparatus of claim 12, wherein the transparent conductive layer comprising ITO has a sheet resistance (Rs) of from about 500-1,500 ohms/square. ### Claim 20 (depends on 12) The concentrating solar power apparatus of claim 12, wherein the transparent conductive layer comprising ITO has a sheet resistance (Rs) of from about 700-1,200 ohms/square. ### Claim 21 (depends on 12) The concentrating solar power apparatus of claim 12, wherein the second layer comprising an oxide and/or nitride of silicon comprises silicon oxide. ### Claim 22 (depends on 12) The concentrating solar power apparatus of claim 12, wherein the second layer comprising an oxide and/or nitride of silicon comprises silicon nitride. ### Claim 23 (depends on 12) The concentrating solar power apparatus of claim 12, wherein the anti-soiling coating further comprises a layer comprising silicon nitride and a layer comprising titanium oxide located between the glass substrate and the first layer comprising silicon oxynitride. ### Claim 24 (depends on 1) The concentrating solar power apparatus of claim 1, wherein the anti-soiling coating comprises a transparent conductive layer comprising ITO located between at least first and second layers comprising silicon nitride. ### Claim 25 (depends on 1) The concentrating solar power apparatus of claim 1, wherein the anti-soiling coating comprises a transparent conductive layer comprising silver located between at least first and second layers comprising silicon nitride. ### Claim 26 (depends on 1) The concentrating solar power apparatus of claim 1, wherein the anti-soiling coating also functions as an anti-reflective (AR) coating due to indices of refraction (n) of its respective layers, wherein the anti-soiling coating comprises a transparent conductive oxide layer having a refractive index (n) of from 1.8 to 2.0 that is sandwiched between and contacting a first dielectric layer having a refractive index (n) of from 1.65 to 1.85 and a second dielectric layer have a refractive index (n) of from 1.5 to 1.7, wherein the first dielectric layer is located between at least the transparent conductive oxide layer and the glass substrate. ### Claim 27 (depends on 26) The concentrating solar power apparatus of claim 26, wherein the transparent conductive oxide layer has an index of refraction (n) at least 0.1 higher than respective indices of the first and second dielectric layers. ### Claim 28 (depends on 26) The concentrating solar power apparatus of claim 26, wherein the transparent conductive oxide layer has an index of refraction (n) at least 0.2 higher than respective indices of the first and second dielectric layers. ### Claim 29 A mirror for use in a concentrating solar power apparatus, the mirror comprising: a glass substrate, an anti-soiling coating, a mirror coating, and wherein the anti-soiling coating also functions as an anti-reflective (AR) coating due to indices of refraction (n) of its respective layers, wherein the anti-soiling coating comprises a transparent conductive oxide layer having a refractive index (n) of from 1.8 to 2.0 that is sandwiched between and contacting a first dielectric layer having a refractive index (n) of from 1.65 to 1.85 and a second dielectric layer have a refractive index (n) of from 1.5 to 1.7, wherein the first dielectric layer is located between at least the transparent conductive oxide layer and the glass substrate, ### Claim 30 (depends on 29) The mirror of claim 29, wherein the transparent conductive oxide layer has an index of refraction (n) at least 0.1 higher than respective indices of the first and second dielectric layers. ### Claim 31 (depends on 29) The mirror of claim 29, wherein the transparent conductive oxide layer has an index of refraction (n) at least 0.2 higher than respective indices of the first and second dielectric layers. ### Claim 32 (depends on 29) The mirror of claim 29, wherein the anti-soiling coating and the mirror coating are located on opposite sides of the glass substrate. ### Claim 33 (depends on 29) The mirror of claim 29, wherein the mirror has a solar reflectance of at least 88%. ### Claim 34 (depends on 29) The minor of claim 29, wherein a reflective layer of the mirror coating comprises silver or aluminum. ### Claim 35 (depends on 29) The mirror of claim 29, wherein, in the anti-soiling coating, the transparent conductive layer comprises ITO, the first dielectric layer comprises silicon oxynitride, and the second dielectric layer comprises silicon oxide.