Editing Solar updraft tower (section)

===Updraft===
* The [[Vortex engine|atmospheric vortex]] proposal<ref>{{cite web|url=http://vortexengine.ca/index.shtml |title=Atmospheric Vortex Engine |publisher=Vortexengine.ca |access-date=2011-09-11}}</ref> replaces the physical chimney by a controlled or 'anchored' cyclonic updraft vortex. Depending on the column gradient of temperature and pressure, or buoyancy, and stability of the vortex, very high-altitude updraft may be achievable. As an alternative to a solar collector, industrial and urban waste-heat could be used to initiate and sustain the updraft in the vortex.
* Telescopic or retractable design may lower a very high chimney for maintenance, or to prevent storm damage.  Hot-air balloon chimney suspension has also been proposed.
* A form of [[solar boiler]] technology placed directly above the turbine at the base of the tower might increase the up-draught.{{citation needed|date=September 2011}}
* Moreno (2006) proposed that a chimney can be economically placed on a hill or mountain slope.<ref name="moreno7026723" />  Klinkman (2014) elaborated on constructing diagonal chimneys.<ref>{{cite patent|country=US|number=8823197|pubdate=2014-09-02|title=Diagonal solar chimney|inventor1-last=Klinkman|inventor1-first=Paul}}</ref> A structure as simply built as a high hoop tunnel, but much longer in length and on a slope, can permanently generate an airflow for producing electricity. Changing the chimney's height differential from 200&nbsp;m (the Manzanares experiment) to 2000&nbsp;m (Charleston Peak in Nevada has a rise of over 2500&nbsp;m, for example) will transfer a factor of ten more of captured solar heat into electric power. Increasing the temperature differential between chimney air and outside air by a factor of ten increases the same chimney's power by one further factor of ten, assuming that the chimney's walls are engineered to take the extra heat. Concentrating solar heat is often done with reflection.
* An inflatable solar chimney power plant has been evaluated analytically and simulated by computational fluid dynamics (CFD) modeling. This idea has been registered as a patent, including the optimal shape of the collector and the analytical profile for the self standing inflatable tower.<ref>{{cite journal |doi=10.1016/j.solener.2013.07.010 |title=Inflatable free-standing flexible solar towers |journal=Solar Energy |volume=98 |pages=85–98 |year=2013 |last1=Putkaradze |first1=Vakhtang |last2=Vorobieff |first2=Peter |last3=Mammoli |first3=Andrea |last4=Fathi |first4=Nima |bibcode=2013SoEn...98...85P }}</ref> The CFD simulation has been evaluated by verification, validation, and uncertainty quantification (VVUQ) of computer simulations by American Society of Mechanical Engineers 2009 standards.<ref>Fathi, Nima, Peter Vorobief, and Seyed Sobhan Aleyasin. "V&V exercise for a solar tower power plant." In ''ASME Verification and Validation Symposium''. 2014.</ref><ref>Vorobieff, Peter V., et al. "Inflatable, free-standing solar updraft tower with optimal geometry and active control." U.S. Patent No. 10,006,443. 26 Jun. 2018.</ref>
* Airtower is a proposal by architect [[Julian Breinersdorfer]] to better exploit the high initial capital outlay of building a very high structure by incorporating it into a high rise building core. The proximity of producer and consumer can also reduce transmission losses.<ref>{{cite news|url=https://www.faz.net/aktuell/wissen/natur/generationenvertrag-vorwaerts-zur-natur-1626516.html |title=Vorwärts zur Natur |newspaper=faz.net |access-date=2011-05-03|last1=Schellnhuber |first1=Hans Joachim }}</ref>