As I worry that this important GHG reduction concept is not strictly CDR, I'm cross-posting this solar photo-catalytic chimneys thread to the geoengineering group:
Brian On Sun, Dec 2, 2018 at 6:37 AM Renaud de RICHTER <renaud.derich...@gmail.com> wrote: > Hi Brian, > > Thank you for your questions and sorry for the delay to answer. > > 1) Currently, non-CO2 GHGases represent nearly *one third of total *radiative > forcing (50% of CO2 radiative forcing). > CO2 represent 66% of total (2.013 W/m2) and non-CO2 GHGs 33% (1.039 W/m2). > Total RF 3.062 W/m2 in 2017. > > Recently, in another post in this group *"**[CDR] Greenhouse gases at new > record high" > <https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/carbondioxideremoval/ao19EeCvgNw/9P2nRdOGAQAJ>* > Bruce Parker gave the estimates of radiative forcing of the principal > GHGs for various RCPs projects. > But for 2011 and for RCP 2.6 in year 2100, the cooling effects of other > climate forcers have been subtracted in the line "*Non-CO2 Rad. Forc."*. > > Your question is how much " *the non-CO2 GHGases in CO2 equivalent units*" > ? According to this link: https://www.esrl.noaa.gov/gmd/aggi/aggi.html > in 2017, the total eq-CO2 were 493, with more or less 403 ppm due to CO2, > so the non-CO2 GHGs represent nearly 90 eq-CO2, or roughly 1/4 of total. > > 2) Solar chimneys with photocatalysts acting in a passive way with no > pressure drop (only few nm coated on the inner part of the collector), > are a NET, which *can earn money* and be cost competitive, because of the > electricity production. > > In this article > <http://lifescienceglobal.com/pms/index.php/jtire/article/viewFile/3103/1802>, > the estimation of the levelized electrical costs LECs for 30 years of > depreciation is 0.090 €/kWh in average (even 0.075 €/kW in very good > locations). > The lifespan of a solar chimney is 100 to 120 years > <https://www.sciencedirect.com/science/article/pii/S014102961300357X>. After > the loans have been repaid, the price of the electricity produced is almost > zero, since there is very little maintenance and almost no consumables. A > PV pannel or an offhore wind tower is 20 to 25 years, while nuclear poser > plants is 60-70 years and coal power plants is 35-40 years. > The author of this article belong to a company who has built more than 100 > cooling towers in Europe. > The photocatalyst will only add 3% to the initial investment costs. > > Coming back to *"**[CDR] Greenhouse gases at new record high" > <https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/carbondioxideremoval/ao19EeCvgNw/9P2nRdOGAQAJ>* > Bruce Parker's post, RCP 8.5 in 2100 is really bad in terms of CH4 > emissions. > I'm not sure a *tipping point* is even considered in this scenario, with > destabilization of the methane hydrates. > For the moment, to my knowledge the only two high scale CH4 atmospheric > removal technologies proposed till today are photocatalytic solar chimneys > <https://www.sciencedirect.com/science/article/pii/S0360128516300569>, > and surface tropospheric Cl atom generation > <https://www.earth-syst-dynam.net/8/1/2017/esd-8-1-2017.pdf>. > > Best > Renaud de Richter, PhD > University of Montpellier, France > > > Le mar. 20 nov. 2018 à 11:46, Brian Cady <briancady...@gmail.com> a > écrit : > >> Hi Renaud, >> >> How much of a problem are the non-CO2 GHGases in CO2 equivalent units? >> How expensive might Solar Photocatalytic Chimneys be per CO2 equivalent >> removed? I guess for that we need to estimate cost, lifespan and GHGs >> processed per lifespan. >> >> Brian >> >> On Sat, Nov 17, 2018 at 4:46 PM Renaud de RICHTER < >> renaud.derich...@gmail.com> wrote: >> >>> Other sources of renewable energy are possible. Please see the >>> attachment. >>> >>> * Current DAC systems with lots of air fans, can be equipped with UV >>> lamps and photocatalysts to destroy/remove the other GHGs >>> >>> * Solar chimneys with turbines where developed to produce electricity, >>> but require large greenhouses. A prototype in Spain worked 3 years non-stop >>> in the 1985's in Manzanares. The chimney was 195m high. >>> >>> * Much smaller and cheaper solar chimneys can be dedicated to *produce >>> ONLY a continuous air-flow*, for instance by using waste heat of >>> thermal power plants (CSP, nuclear, geothermal, etc.) and allowing water >>> savings if used as dry cooling towers. >>> >>> * Solar chimneys dedicated to produce an air-flow can be used by DAC >>> systems to save the investment in fans and in their electricity >>> consumption, and *halve the land footprint* >>> >>> >>> >>> >>> Le jeu. 8 nov. 2018 à 00:35, Andrew Lockley <andrew.lock...@gmail.com> >>> a écrit : >>> >>>> Just resurfacing the attached, which envisages a competing vision of >>>> continuous DAC operation >>>> >>>> >>>> >>>> >>>> On Wed, 7 Nov 2018, 18:44 Greg Rau <gh...@sbcglobal.net wrote: >>>> >>>>> >>>>> >>>>> via Leon Di Marco: >>>>> >>>>> >>>>> https://www.carbonbrief.org/combining-renewables-with-direct-air-capture-for-net-negative-emissions >>>>> >>>>> >>>>> Wohland, J. et al. (2018) Negative Emission Potential of Direct Air >>>>> Capture Powered by Renewable Excess Electricity in Europe, Earth’s Future, >>>>> doi:10.1029/2018EF000954 >>>>> <https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018EF000954> >>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Carbon Dioxide Removal" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to carbondioxideremoval+unsubscr...@googlegroups.com. >>>>> To post to this group, send email to >>>>> carbondioxideremo...@googlegroups.com. >>>>> Visit this group at >>>>> https://groups.google.com/group/CarbonDioxideRemoval. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/CarbonDioxideRemoval/1888159085.535754.1541616264019%40mail.yahoo.com >>>>> <https://groups.google.com/d/msgid/CarbonDioxideRemoval/1888159085.535754.1541616264019%40mail.yahoo.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Carbon Dioxide Removal" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to carbondioxideremoval+unsubscr...@googlegroups.com. >>>> To post to this group, send email to >>>> carbondioxideremo...@googlegroups.com. >>>> Visit this group at >>>> https://groups.google.com/group/CarbonDioxideRemoval. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/CarbonDioxideRemoval/CAJ3C-06MRTJsSF03G8%2BSuSKEZ4gCGxQj5SirU9LtkASXP_HdkA%40mail.gmail.com >>>> <https://groups.google.com/d/msgid/CarbonDioxideRemoval/CAJ3C-06MRTJsSF03G8%2BSuSKEZ4gCGxQj5SirU9LtkASXP_HdkA%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Carbon Dioxide Removal" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to carbondioxideremoval+unsubscr...@googlegroups.com. >>> To post to this group, send email to >>> carbondioxideremo...@googlegroups.com. >>> Visit this group at https://groups.google.com/group/CarbonDioxideRemoval >>> . >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/CarbonDioxideRemoval/CAHodn99uUOEtt83_bNb804e4YsB_NUSjXDbMLb-yvA7sB%3DaB0g%40mail.gmail.com >>> <https://groups.google.com/d/msgid/CarbonDioxideRemoval/CAHodn99uUOEtt83_bNb804e4YsB_NUSjXDbMLb-yvA7sB%3DaB0g%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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