144:(CNT) templates. The CNT substrates will allow customizable interactions between neighboring molecules which greatly helps in fine tuning the properties of the fuel, for example an increase in the amount of energy stored. Through experimental procedures, researchers were able to get the first proof of principle that the hybrid nanostructure works as a functional thermal fuel. Azobenzenes have the advantage of absorbing wavelengths that are very abundant in sunlight, when this happens the molecule transforms from a trans-isomer to a cis-isomer which has a higher energy state of about 0.6 eV. To bring the molecule back down to its original state, i.e. release the energy it had collected, there are a few options. The first is to apply heat but that is associated with a cost which, relative to the amount of heat that will be produced from the release, is not cost efficient. The second, more effective option is to use a catalyst that lowers the thermal barrier and allows the heat to be released, almost like a switch. The transition back from cis to trans can also be triggered by blue visible light.
50:. This is normally done in a two-step process so that hydrogen and oxygen are not produced in the same chamber, which creates an explosion hazard. Another approach involves taking the hydrogen created in this process and combining it with carbon dioxide to create methane. The benefit of this approach is that there is an established infrastructure for transporting and burning methane for power generation, which is not true for hydrogen. One main drawback to both of these approaches is common to most methods of energy storage: adding an extra step between energy collection and electricity production drastically decreases the efficiency of the overall process.
161:
stoves or small personal heaters that can be charged in the sun to providing medical sanitation in off-grid areas, and plans are even in the works to use the system developed at MIT as a window de-icing system in automobiles. It also has the ability to be scaled up and heat larger homes or buildings or even heat bodies of water. A solar thermal fuel would ideally be able to cycle indefinitely without degradation, making it ideal for larger scale implementations that generally would need more replacements of other forms of storage.
132:
87:
508:
99:, Ea, is used to characterize how easy or hard it is for the reaction to proceed. If the activation energy is too small the fuel will tend to spontaneously move to the more stable state, providing limited usefulness as a storage medium. However, if the activation energy is very large, the energy expended to extract the energy from the fuel will effectively reduce the amount of energy that the fuel can store. Finding a useful molecule for a
514:
1310:
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62:
into dianthracene was investigated as a means of storing solar energy, as well as the photodimerization of the naphthalene series. In the 70’s and 80’s a fuel had been made from another reversible chemical, the norbornadiene to quadricyclane transformation cycle, but this failed because the reversal
94:
In order for an isomer to store energy then, it must be metastable as shown above. This results in a trade-off between the stability of the fuel isomer and how much energy must be put in to reverse the reaction when it is time to use the fuel. The isomer stores energy as strain energy in its bonds.
160:
There are a wide variety of both potential and current applications for solar chemical fuels. One of the major pros of this technology is its scalability. Since the energy can be stored and then later converted to heat when needed, it is ideal for smaller on the go units. These range from portable
151:
comparable to lithium-ion batteries, while simultaneously increasing the stability of the activated fuel from several minutes to more than a year and allowing for large numbers of cycles without significant degradation. Further research is being done in search of even more improvement by examining
139:
Research into both the azobenzene and norbonadiene-quadricyclane systems was abandoned in the 1980s as unpractical due to problems with degradation, instability, low energy density, and cost. With recent advances in computing power though, there has been renewed interest in finding materials for
63:
process had a low potential. Ruthenium-based molecules were also attempted, but this was dismissed because ruthenium is both rare and too heavy of a material. In the past decade, a new hybrid nanostructure was theorized as a new approach to this previously known concept of solar energy storage.
123:
couple and its derivatives have been extensively investigated for solar energy storage processes. Norbornadiene is converted to quadricyclane using energy extracted from sunlight, and the controlled release of the strain energy stored in quadricyclane (about 110
103:
requires finding the proper balance between the yield, the light absorption of the molecule, the stability of the molecule in the metastable state, and how many times the molecule can be cycled without degrading.
140:
solar thermal fuels. In 2011, researchers at MIT used time-dependent density functional theory, which models systems at an atomic level, to design a system composed of azobenzene molecules bonded to
83:. While photodimerization stores the energy from sunlight in new chemical bonds, photoisomerization stores solar energy by reorienting existing chemical bonds into a higher energy configuration.
31:
in plants, which converts solar energy into the chemical bonds of glucose molecules, but without using living organisms, which is why it is also called
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446:
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246:
Kolpak, Alexie; Jeffrey
Grossman (2011). "Azobenzene-Functionalized Carbon Nanotubes As High-Energy Density Solar Thermal Fuels".
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Durgan, E.; Jeffrey
Grossman (4 March 2013). "Photoswitchable molecular rings for solar-thermal energy storage".
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A promising approach is to use focused sunlight to provide the energy needed to split water into its constituent
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The more strained the bonds are the more energy they can store, but the less stable the molecule is. The
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Magnuson, A; et al. (2009). "Biomimetic and
Microbial Approaches to Solar Fuel Generation".
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128:) as it relaxes back to norbornadiene allows the energy to be extracted again for use later.
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Norbornadiene - Quadricyclane couple is of potential interest for solar energy storage
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and its derivatives, have been investigated as potential energy storing isomers. The
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different possible combinations of substrates and photoactive molecules.
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refers to a number of possible processes that harness
403:, March 2004 article on Paul Scherrer Institute work
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Photodimerization is the light induced formation of
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397:- Paul Scherrer Institute, Villigen, Switzerland.
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46:in the presence of a metallic catalyst such as
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391:- Australian National University, Canberra.
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950:
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389:ANU Thermochemical energy storage system
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1004:Financial incentives for photovoltaics
58:As early as 1909, the dimerization of
27:. The idea is conceptually similar to
322:Journal of Physical Chemistry Letters
7:
1321:
241:
239:
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409:Plataforma Solar de Almería, Spain,
79:is the light induced formation of
14:
1115:Building-integrated photovoltaics
1320:
1309:
1308:
518:
512:
506:
395:Laboratory for Solar Technology
111:among other compounds, such as
107:Various ketones, azepines and
1:
1120:Passive solar building design
546:Passive solar building design
366:"Materials Processing Center"
180:Accounts of Chemical Research
401:Power & Energy Magazine
23:by absorbing sunlight in a
1370:
623:Photovoltaic power station
1304:
688:artificial photosynthesis
504:
462:
33:artificial photosynthesis
1224:Solar water disinfection
718:Thermoelectric generator
147:This system provides an
932:Solar Shade Control Act
713:Space-based solar power
407:Solar Chemistry Project
295:. Academic Press, Inc.
219:. Academic Press, Inc.
90:Anthracene dimerization
1296:Solar power by country
971:Thermal energy storage
596:Nanocrystal solar cell
551:Solar air conditioning
289:Bolton, James (1977).
213:Bolton, James (1977).
136:
91:
1177:Salt evaporation pond
1146:Hybrid solar lighting
966:Phase-change material
292:Solar Power and Fuels
216:Solar Power and Fuels
134:
89:
703:Solar thermal rocket
1271:Solar water heating
1045:Solar water heating
961:Grid energy storage
708:Solar updraft tower
617:Photovoltaic module
612:Photovoltaic effect
566:Solar water heating
260:2011NanoL..11.3156K
1099:Solar-powered pump
693:Solar-pumped laser
606:Photovoltaic array
601:Organic solar cell
584:and related topics
137:
92:
77:photoisomerization
1336:
1335:
1279:
1278:
1261:Solar combisystem
1219:Soil solarization
1125:Urban heat island
1053:
1052:
1025:Electric aircraft
940:
939:
656:Solar power tower
344:10.1021/jz301877n
302:978-0-12-112350-5
268:10.1021/nl201357n
226:978-0-12-112350-5
192:10.1021/ar900127h
186:(12): 1899–1908.
97:activation energy
25:chemical reaction
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1266:Solar controller
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651:Parabolic trough
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254:(8): 3156–3162.
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67:Chemical storage
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999:Feed-in tariff
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994:Cost by source
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419:Hydrogen Solar
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383:External links
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328:(6): 854–860.
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149:energy density
109:norbornadienes
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29:photosynthesis
17:Solar chemical
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581:Photovoltaics
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556:Solar chimney
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121:quadricyclane
118:
117:norbornadiene
114:
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34:
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26:
22:
18:
1325:
1313:
1240:Desalination
1233:Desalination
1212:Disinfection
1203:Solar cooker
1170:Process heat
1071:horticulture
1058:Applications
1018:Applications
1009:Net metering
945:Distribution
881:South Africa
871:Saudi Arabia
683:
672:and proposed
670:Experimental
638:Concentrated
571:Thermal mass
456:Solar energy
369:. Retrieved
360:
325:
321:
307:, p. 238-240
291:
284:
251:
248:Nano Letters
247:
231:, p. 235-237
215:
208:
183:
179:
173:
159:
156:Applications
146:
138:
106:
93:
70:
57:
37:
21:solar energy
16:
15:
1245:Solar still
1141:Daylighting
1079:Agrivoltaic
1066:Agriculture
851:New Zealand
846:Netherlands
529:Solar power
1343:Categories
1187:Solar pond
1161:Solar Tuki
1156:Solar lamp
1151:Light tube
1089:Polytunnel
1084:Greenhouse
728:By country
698:Solar sail
628:Solar cell
561:Solar pond
371:2017-08-09
165:References
113:azobenzene
101:solar fuel
60:anthracene
54:Background
1094:Row cover
826:Lithuania
746:Australia
646:Heliostat
415:- Israel,
330:CiteSeerX
1315:Category
1284:See also
1134:Lighting
1108:Building
987:Adoption
976:seasonal
947:and uses
891:Thailand
861:Portugal
856:Pakistan
486:Concepts
477:Timeline
413:Isracast
352:26291346
276:21688811
200:19757805
40:hydrogen
1327:Commons
1196:Cooking
954:Storage
901:Ukraine
876:Somalia
866:Romania
841:Myanmar
836:Morocco
791:Germany
786:Georgia
781:Denmark
756:Belgium
751:Austria
741:Armenia
736:Albania
538:Thermal
493:The Sun
472:Outline
256:Bibcode
126:kJ/mole
81:isomers
896:Turkey
831:Mexico
821:Kosovo
806:Israel
796:Greece
766:Canada
761:Brazil
350:
332:
299:
274:
223:
198:
73:dimers
44:oxygen
925:Legal
916:Yemen
886:Spain
816:Japan
811:Italy
801:India
771:China
467:Index
421:- UK.
1069:and
686:and
348:PMID
297:ISBN
272:PMID
221:ISBN
196:PMID
75:and
48:zinc
42:and
340:doi
264:doi
188:doi
1345::
346:.
338:.
324:.
312:^
270:.
262:.
252:11
250:.
236:^
194:.
184:42
182:.
35:.
448:e
441:t
434:v
374:.
354:.
342::
326:4
305:.
278:.
266::
258::
229:.
202:.
190::
119:-
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
