Solar collector

Abstract

The present invention provides highly efficient solar energy collectors that use conductive fluids that are mixed with dark absorption pigmentation or objects. The pigmentation or objects are provided in the fluid itself, giving the fluid a dark appearance. A preferred embodiment relates to a method of capturing solar energy in the form of selective radiation surfaced (dark surfaced) microbeads, nanobeads, particulates or nano-particulates immersed and carried in a high temperature oil or other working fluid. The fluid containing these dark materials more readily absorbs solar radiation, and makes the absorbed radiation more readily available for transmission and use. Specially adapted enclosures are also provided for use with such fluids. Inexpensive methods of use and production of the fluids and enclosures are also provided.

1 . An absorption medium for use in a solar energy collector comprising a fluid that does not break down at high temperatures mixed with a dark material for increased absorption of solar energy in the fluid.  
   
   
       2 . The absorption medium of  claim 1  wherein said fluid is a member selected from the group of an oil, a silicate, a synthetic silicone, a fluorocarbon, a halogenated solvent, water and combinations thereof.  
   
   
       3 . The absorption medium of  claim 1  wherein said dark material is a pigment selected from the group of copper oxide, copper sulfide, iron oxide, chrome oxide, nickel oxide, carbon, chrome oxide, nickel oxide, silicon carbide and combinations thereof.  
   
   
       4 . The absorption medium of  claim 1  wherein said dark material is a pigment selected from the group of a sulfide complex of lead, copper and silver; nickel sulfide; zinc sulfide; carbon bound in silica gel; a metal oxide gel; carbon bucky balls, and combinations thereof.  
   
   
       5 . The absorption medium of  claim 1  wherein said dark material is a low refractive index pigment.  
   
   
       6 . An absorption medium for use in a solar energy collector comprising a fluid that does not break down at high temperatures mixed with a dark material for increased absorption of solar energy in the fluid wherein said fluid is a member selected from the group of an oil, a silicate, a synthetic silicone, a fluorocarbon, a halogenated solvent, water and combinations thereof, and wherein said dark material is a pigment selected from the group of copper oxide, copper sulfide, iron oxide, chrome oxide, nickel oxide, carbon, chrome oxide, nickel oxide, silicon carbide and combinations thereof.  
   
   
       7 . The fluid of  claim 1  wherein said dark material is a member selected from the group of nanobeads having selective radiation surfaces, nanoshperes having selective radiation surfaces, nano-particulates having selective radiation surfaces, microbeads having selective radiation surfaces, microshperes having selective radiation surfaces, microparticulates having selective radiation surfaces, and combinations thereof.  
   
   
       8 . The fluid of  claim 7  wherein said member is provided with a surface coating selected from the group of carbon sulfide, copper oxide, copper sulfide, iron oxide, chrome oxide, nickel oxide, carbon, chrome oxide, nickel oxide, silicon carbide and combinations thereof.  
   
   
       9 . The fluid of  claim 7  wherein said member is provided with a surface coating selected from the group of a metal oxide, a metal sulfide, and combinations thereof.  
   
   
       10 . An absorption medium for use in a solar energy collector comprising a fluid that does not break down at high temperatures mixed with a dark material for increased absorption of solar energy in the fluid wherein said fluid is a member selected from the group of an oil, a silicate, a synthetic silicone, a fluorocarbon, a halogenated solvent, water and combinations thereof, and wherein said dark material is a member selected from the group of nanobeads having selective radiation surfaces, nanoshperes having selective radiation surfaces, nano-particulates having selective radiation surfaces, microbeads having selective radiation surfaces, microshperes having selective radiation surfaces, microparticulates having selective radiation surfaces, and combinations thereof, and wherein said dark material member is provided with a surface coating selected from the group of a metal oxide, a metal sulfide, and combinations thereof.  
   
   
       11 . An absorption fluid for use in a solar energy collector comprising a mixture of an oil that does not break down at high temperatures, a dark pigment having a low refractive index, and at least one member selected from the group of nanobeads having selective radiation surfaces, nanoshperes having selective radiation surfaces, nano-particulates having selective radiation surfaces, microbeads having selective radiation surfaces, microshperes having selective radiation surfaces, microparticulates having selective radiation surfaces, and combinations thereof.  
   
   
       12 . The fluid of  claim 1  wherein said dark material comprises a plurality of photonic crystals, each such crystal comprising a lattice of differently sized nanobeads for selectively canceling certain wavelengths and allowing absorption of other wavelengths.  
   
   
       13 . The fluid of  claim 1  wherein said dark material comprises a plurality of photonic crystals, each such crystal comprising a lattice of nanospheres and voids wherein the differences between the refractive index of said nanospheres and their surrounding voids cancels certain wavelengths and allows absorption of other wavelengths.  
   
   
       14 . An absorption medium for use in a solar energy collector comprising a fluid that does not break down at high temperatures mixed with a dark material for increased absorption of solar energy in the fluid wherein said fluid is a member selected from the group of an oil, a silicate, a synthetic silicone, a fluorocarbon, a halogenated solvent, water and combinations thereof, and wherein said dark material comprises a plurality of photonic crystals, each such crystal comprising a lattice of differently sized nanobeads for selectively canceling certain wavelengths and allowing absorption of other wavelengths.  
   
   
       15 . A solar energy collector comprising a body having at least one channel therein that is exposed to sunlight, a phase-change material provided in and partially filling said channel, and at least one fluid provided with said material in said channel, such that when the collector is receiving the rays of the sun the fluid transfers heat to the material causing it to melt.  
   
   
       16 . The collector of  claim 15  wherein said phase change material is mixed with a dark material for increased absorption of solar energy.  
   
   
       17 . In combination, a solar energy collector and an absorption medium wherein said collector comprises a body defining at least one channel that is exposed to sunlight, and said absorption medium comprises a fluid that does not break down at high temperatures mixed with a dark material for increased absorption of solar energy in the fluid, said medium being provided in said channel.  
   
   
       18 . The combination of  claim 17  wherein said channel further comprises a lower reflective surface that reflects solar energy onto the medium provided therein.  
   
   
       19 . The combination of  claim 18  wherein said reflective surface material is selected from the group consisting of aluminum, silver, foil, metal-coated film, and combinations thereof.  
   
   
       20 . The combination of  claim 17  wherein said channel comprises at least one tubular member.  
   
   
       21 . The combination of  claim 20  wherein the upper portion of said tubular member allows the rays of the sun to enter, and wherein the lower portion comprises a surface that reflects the rays of the sun into said tubular member for absorption by said medium.  
   
   
       22 . The combination of  claim 17  wherein said channel comprises a first tubular member having a perimeter, and a second tubular member having a smaller perimeter provided inside said first tubular member wherein said absorption medium is provided in said second tubular member.  
   
   
       23 . The combination of  claim 22  wherein the upper portions of said tubular members allow the rays of the sun to enter, and wherein the lower portion of at least one of said tubular members comprises a surface that reflects the rays of the sun into said second tubular member for absorption by said medium.  
   
   
       24 . The combination of  claim 22  wherein insulation is provided between said first tubular member and said second tubular member that allows the rays of the sun to enter, but prevents heat from exiting.  
   
   
       25 . The combination of  claim 24  wherein said insulation is selected from the group of a xerogel, an aerogel and combinations thereof.  
   
   
       26 . The combination of  claim 22  wherein a vacuum is provided between said first tubular member and said second tubular member.  
   
   
       27 . The combination of  claim 17  wherein said dark material is a pigment selected from the group of copper oxide, copper sulfide, iron oxide, chrome oxide, nickel oxide, carbon, chrome oxide, nickel oxide, silicon carbide and combinations thereof.  
   
   
       28 . The combination of  claim 17  wherein said dark material is a pigment selected from the group of a sulfide complex of lead, copper and silver; nickel sulfide; zinc sulfide; carbon bound in silica gel; a metal oxide gel; carbon bucky balls, and combinations thereof.  
   
   
       29 . The combination of  claim 17  wherein said dark material is a member selected from the group of nanobeads having selective radiation surfaces, nanoshperes having selective radiation surfaces, nano-particulates having selective radiation surfaces, microbeads having selective radiation surfaces, microshperes having selective radiation surfaces, microparticulates having selective radiation surfaces, and combinations thereof.  
   
   
       30 . The combination of  claim 17  wherein said dark material is a plurality of photonic crystals, each such crystal comprising a lattice of differently sized nanobeads for selectively canceling certain wavelengths and allowing absorption of other wavelengths.  
   
   
       31 . In combination, a solar energy collector and an absorption medium wherein said collector comprises a body defining at least one channel that is exposed to sunlight, and said absorption medium comprises a fluid that does not break down at high temperatures mixed with a dark material for increased absorption of solar energy in the fluid, said medium being provided in said channel, wherein said channel further comprises a lower reflective surface that reflects solar energy onto the medium provided therein, and wherein said fluid is a member selected from the group of an oil, a silicate, a synthetic silicone, a fluorocarbon, a halogenated solvent, water and combinations thereof, and wherein said dark material is a pigment selected from the group of copper oxide, copper sulfide, iron oxide, chrome oxide, nickel oxide, carbon, chrome oxide, nickel oxide, silicon carbide and combinations thereof.  
   
   
       32 . In combination, a solar energy collector and an absorption medium wherein said collector comprises a body defining at least one channel that is exposed to sunlight, and said absorption medium comprises a fluid that does not break down at high temperatures mixed with a dark material for increased absorption of solar energy in the fluid, said medium being provided in said channel, wherein said channel further comprises a lower reflective surface that reflects solar energy onto the medium provided therein, and wherein said fluid is a member selected from the group of an oil, a silicate, a synthetic silicone, a fluorocarbon, a halogenated solvent, water and combinations thereof, and wherein said dark material is a member selected from the group of nanobeads having selective radiation surfaces, nanoshperes having selective radiation surfaces, nano-particulates having selective radiation surfaces, microbeads having selective radiation surfaces, microshperes having selective radiation surfaces, microparticulates having selective radiation surfaces, and combinations thereof, and wherein said dark material member is provided with a surface coating selected from the group of a metal oxide, a metal sulfide, and combinations thereof.  
   
   
       33 . In combination, a solar energy collector and an absorption medium wherein said collector comprises a body defining at least one channel that is exposed to sunlight, and said absorption medium comprises a fluid that does not break down at high temperatures mixed with a dark material for increased absorption of solar energy in the fluid, said medium being provided in said channel, wherein said channel further comprises a lower reflective surface that reflects solar energy onto the medium provided therein, and wherein said fluid is a member selected from the group of an oil, a silicate, a synthetic silicone, a fluorocarbon, a halogenated solvent, water and combinations thereof, and wherein said dark material comprises a plurality of photonic crystals, each such crystal comprising a lattice of differently sized nanobeads for selectively canceling certain wavelengths and allowing absorption of other wavelengths.  
   
   
       34 . The combination of  claim 17  further comprising a plurality of dark surface coated strands are provided in said channel with said medium for further absorption and transfer of energy from the sun.  
   
   
       35 . A method for collecting solar radiation comprising the steps of: 
 a. positioning a solar collector having a body defining at least one channel therein such that said channel is exposed to sunlight during the day, said channel having a lower reflective surface for reflecting solar energy;    b. providing an absorption medium in said channel, said medium comprising a fluid that does not break down at high temperatures mixed with a dark material for increased absorption of solar energy; and    c. causing said medium to flow through said channel such that solar energy is absorbed by said medium when it is in said channel, and removed from said medium when it is outside of said channel.