tag:blogger.com,1999:blog-19508699.post7359988867607893299..comments2024-03-29T06:38:18.116+00:00Comments on Energy Balance: Hydro, not so Green?Professor Chris Rhodeshttp://www.blogger.com/profile/12060542089215379056noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-19508699.post-81321511320138465372017-06-01T12:58:34.952+01:002017-06-01T12:58:34.952+01:00KBCagri provide importers, exporters and suppliers...KBCagri provide importers, exporters and suppliers of bio compost manufacturers in chennai india. bio compost manufactureres, bio compost suppliers, bio compost exporters, bio compost importers in andhra pradesh, telangana, tamilnadu and Kerala. VIEW MORE :- <a href="http://www.kbcagri.com/about-us.php" rel="nofollow">bio compost in India</a>Anonymoushttps://www.blogger.com/profile/14098705823053222069noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-83837985253963273242010-11-19T09:16:23.792+00:002010-11-19T09:16:23.792+00:00Hello, I do not agree with the previous commentato...Hello, I do not agree with the previous commentator - not so simplebuy viagra onlinehttp://www.aiesec.fi/noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-17961804837275371982008-09-17T09:08:00.000+01:002008-09-17T09:08:00.000+01:00Hi Theo,just an update:if you look at that link an...Hi Theo,<BR/><BR/>just an update:<BR/><BR/>if you look at that link and the equation for GWP (x), and then reduce it for t=o (TH=0), you get:<BR/><BR/>GWP(CH4) = aCH4/aCO2 x MWCO2/MWCH4 = .53/.015 x 44/16 = 97.2. i.e. about 100. The point is that it's one kg of each gas that is assumed to be added to the atmosphere, and these concentrations thus divide out except that the values for "a(x)" are usually quoted in units of W/m^2.ppmv (i.e. by volume).<BR/><BR/>Since the volume of a kg of a gas depends on the MW of its molecules you need the correction factor as shown. i.e the volume of a kg of CO2 is less than that of a kg of CH4 by a factor of 44/16.<BR/><BR/>Both gases will over time be removed from the atmosphere, with lifetimes of about 12 years for methane and 50 - 200 years for CO2 depending on where it is, but I am assuming a kind of steady-state situation where both gases are continually emitted, as seems to be the case, although the amounts of each may vary over time. However, the latter case is complex and goes beyond this simple definition of GWP.<BR/><BR/>The point is that in terms of assessing the relative GWP of gases relative to CO2, it is important to note the time interval that is being quoted.<BR/><BR/>O.K.?<BR/><BR/>Regards,<BR/><BR/>Chris.Professor Chris Rhodeshttps://www.blogger.com/profile/12060542089215379056noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-46967498926265979282008-09-16T10:39:00.000+01:002008-09-16T10:39:00.000+01:00I worked it out basically from the definition for ...I worked it out basically from the definition for Global warming potential in:<BR/><BR/>http://en.wikipedia.org/wiki/Global_warming_potential<BR/><BR/>along with some factors for atmospheric lifetimes for CH4 and CO2 (the latter is quite variable, between 50 and 200 years), but from the data in that link, if the warming potential (relative to CO2) for methane is 7.6 (over 500 years), 25 (100 years), 72 (20 years) - or the other set of data) a value of 100 is reasonable for zero-years, i.e. instantaneous radiative forcing by a given MASS of each.Professor Chris Rhodeshttps://www.blogger.com/profile/12060542089215379056noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-81322350032603765582008-09-15T03:19:00.000+01:002008-09-15T03:19:00.000+01:00Do you have a reference for the 100x warming power...Do you have a reference for the 100x warming power of CH4 compared to CO2? Thanks.Unknownhttps://www.blogger.com/profile/16539885864807705905noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-39983028653311565062007-10-01T12:17:00.000+01:002007-10-01T12:17:00.000+01:00Sorry Charles, but I don't buy your argument. In r...Sorry Charles, but I don't buy your argument. <BR/><BR/>In response to your first point, yes the carbon volume in the atmosphere stays the same, but it's not in the same form. You're trapping CO2 and emitting methane, which is a much nastier greenhouse gas.<BR/><BR/>As for your second point, your 'solution' doesn't cater for areas where you have marked dry and rainy seasons. In the dry season, when the water level is low, plants grow down to the waters' edge trapping CO2. Then in the wet season, they get covered, rot, and release methane. It's not a once-off that can be solved by clearing vegetation, it's a continuous methane emitting system.<BR/><BR/>No we shouldn't drain the everglades, but maybe we should reconsider our views of how green hydro power is. (It can be green, but it often isn't).Liamhttps://www.blogger.com/profile/17662992576298651054noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-56343524382118849822007-08-17T07:05:00.000+01:002007-08-17T07:05:00.000+01:00I agree with you completely, and it would be plain...I agree with you completely, and it would be plain daft to curb hydro-power. I see how well Norway especially and Canada and Switzerland too use it, and we should follow that lead. It is fully renewable whatever "faults" it may have.<BR/><BR/>I think the emissions problem is negligible compared to the benefits from it and the argument that the dams will become silted-up is surely not tenable as they could be dug-out, couldn't they.<BR/><BR/>I saw this story and found it interesting but worrying if the climate change movement might be hijacked to actually remove something so beneficial, using an excuse based on emissions. It worries me if the UN are taking it seriously.<BR/><BR/>Chris.Professor Chris Rhodeshttps://www.blogger.com/profile/12060542089215379056noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-70233916105495372672007-07-26T22:40:00.000+01:002007-07-26T22:40:00.000+01:00It should be noted that hydropower is absolutly ne...It should be noted that hydropower is absolutly necissary for dispatchable power. The only thing besides dam/pumped hydro that can be dispatched quickly is natural gas, diesel, and some types of coal power plants.<BR/><BR/>With power sources that act as negative load rather than baseload (wind, sometimes solar) the need is even more pronounced. The only reason Denmark can utilize so much wind is the tie in with the Sweedish hydroelectric grid.Unknownhttps://www.blogger.com/profile/04635514928258113448noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-51827213584618399112007-07-25T07:53:00.000+01:002007-07-25T07:53:00.000+01:00Hi Charles!Fair comment! As I say, in my opinion w...Hi Charles!<BR/><BR/>Fair comment! As I say, in my opinion we should use all the hydropower we can get. On balance, and against that backdrop of oil and gas running short, it is a good option, and fully renewable too! I found the matter interesting and thought I would share it on here. If the UN are involved in it, I think we might hear more on the subject? But like you, I hope there will not be a "culling" of hydroelectric power. It is interesting that it is developing nations that depend more on this form of generation than the industrialised nations, and I wonder if there is some political agenda underlying this present "concern"?<BR/><BR/>Regards,<BR/><BR/>Chris.Professor Chris Rhodeshttps://www.blogger.com/profile/12060542089215379056noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-55476780516802334852007-07-24T20:44:00.000+01:002007-07-24T20:44:00.000+01:00I see several problems with this line of argument....I see several problems with this line of argument. First the carbon captured by organic material in a man made lake comes from the earth's atmosphere. Thus it does not incease the ammount of carbon tied up in the carbon cycle. Second there are things that can be done to control methane emissions. Plant material that would go under water when an impounded lake is filled, can be removed, and burned. Ditto for aquatic plants growing in the lake. But lake managers have a slightly different take on this issue. They argue that aquatic plants tend to support wildlife. By the way, we have the same carbon issues with natutal lakes and wet lands. Should we drain Everglades to limit carbon emissions? Hydro power not green? That is downright crazy.Anonymousnoreply@blogger.com