Editing Solar energy (section)

==Fuel production==
[[File:Photo of the Week- Boosting Solar Technology (8722948189).jpg|thumb|Concentrated solar panels are getting a power boost. [[Pacific Northwest National Laboratory]] (PNNL) will be testing a new concentrated solar power system – one that can help natural gas power plants reduce their fuel usage by up to 20 percent.{{Update inline|date=November 2021}}]]
{{Main|Solar chemical|Solar fuel|Artificial photosynthesis}}
Solar chemical processes use solar energy to drive chemical reactions. These processes offset energy that would otherwise come from a fossil fuel source and can also convert solar energy into storable and transportable fuels. Solar induced chemical reactions can be divided into thermochemical or [[photochemical]].<ref>Bolton (1977), p. 1</ref> A variety of fuels can be produced by [[artificial photosynthesis]].<ref>Wasielewski MR Photoinduced electron transfer in supramolecular systems for artificial photosynthesis. Chem. Rev. 1992; 92: 435–61.</ref> The multielectron catalytic chemistry involved in making carbon-based fuels (such as [[methanol]]) from reduction of [[carbon dioxide]] is challenging; a feasible alternative is [[hydrogen]] production from protons, though use of water as the source of electrons (as plants do) requires mastering the multielectron oxidation of two water molecules to molecular oxygen.<ref>Hammarstrom L. and Hammes-Schiffer S. Artificial Photosynthesis and Solar Fuels. Accounts of Chemical Research 2009; 42 (12): 1859–60.</ref> Some have envisaged working solar fuel plants in coastal metropolitan areas by 2050{{snd}} the splitting of seawater providing hydrogen to be run through adjacent fuel-cell electric power plants and the pure water by-product going directly into the municipal water system.<ref>Gray H.B. Powering the planet with solar fuel. Nature Chemistry 2009; 1: 7.</ref> In addition, chemical energy storage is another solution to solar energy storage.<ref>{{Cite journal |last1=Feng |first1=Hao |last2=Liu |first2=Jian |last3=Zhang |first3=Ying |last4=Liu |first4=Dong |date=2022-06-20 |title=Solar Energy Storage in an All-Vanadium Photoelectrochemical Cell: Structural Effect of Titania Nanocatalyst in Photoanode |journal=Energies |language=en |volume=15 |issue=12 |pages=4508 |doi=10.3390/en15124508 |issn=1996-1073|doi-access=free }}</ref> 

[[Hydrogen production]] technologies have been a significant area of solar chemical research since the 1970s. Aside from electrolysis driven by photovoltaic or photochemical cells, several thermochemical processes have also been explored. One such route uses concentrators to split water into oxygen and hydrogen at high temperatures ({{convert|2300|-|2600|C|disp=or|sigfig=2}}).<ref>Agrafiotis (2005), p. 409</ref> Another approach uses the heat from solar concentrators to drive the [[steam reforming|steam reformation]] of natural gas thereby increasing the overall hydrogen yield compared to conventional reforming methods.<ref>Zedtwitz (2006), p. 1333</ref> Thermochemical cycles characterized by the decomposition and regeneration of reactants present another avenue for hydrogen production. The Solzinc process under development at the [[Weizmann Institute of Science]] uses a 1&nbsp;MW solar furnace to decompose [[zinc oxide]] (ZnO) at temperatures above {{convert|1200|C|sigfig=2}}. This initial reaction produces pure zinc, which can subsequently be reacted with water to produce hydrogen.<ref>{{cite web|title=Solar Energy Project at the Weizmann Institute Promises to Advance the use of Hydrogen Fuel|publisher=Weizmann Institute of Science|url=http://wis-wander.weizmann.ac.il/site/en/weizman.asp?pi=371&doc_id=4210|access-date=25 June 2008|url-status=dead|archive-url=https://web.archive.org/web/20080406124059/http://wis-wander.weizmann.ac.il/site/en/weizman.asp?pi=371&doc_id=4210|archive-date=6 April 2008}}</ref>