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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> extropy-chat-bounces@lists.extropy.org [mailto:extropy-chat-bounces@lists.extropy.org] <b>On Behalf Of </b>ablainey@aol.com<br><b>Sent:</b> Sunday, December 23, 2012 6:16 AM<br><b>To:</b> extropy-chat@lists.extropy.org<br><b>Subject:</b> Re: [ExI] eroei forward for kennedy, p.e.<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>That's useful. Thanks Robert and thanks spike for forwarding. <o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Ja! Kennedy’s first post here is great, thanks Robert. It really has me thinking, since I too am a big fan of BOTECs as Robert mentions in his post. Perhaps it’s a PE thing. {8-]<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Here’s one I did some time ago: using all conservative engineering estimates and reasonable energy transport efficiencies, what fraction of the USA land area would need to be blanketed by solar cells to use that as our only energy source? Ten years ago, I BOTECed nearly a quarter of the land area, assuming we do stuff like solar-energy driven biomass to alkanes so that we get to continue using our beloved Detroits with our soul-stirring V8s and such.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>After doing a series of those BOTECs, any realistic sustainable energy scenario I can imagine involves waaaay more energy austerity than that to which we have grown so fondly accustomed. In energy conservation, the fruit hangs an order of magnitude lower than the next higher levels of fruit.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Here’s what I am trying to imagine: assume the singularity doesn’t happen, never mind for now why. Assume Keith’s vision of space based solar either doesn’t come to pass or is developed in parallel, and all our miracle cures fail, such as controlled nuclear fusion, thorium power etc, none of that cool stuff ever works out. Assume away war and assume some arbitrary population equilibrium, say 10 or 20 billion proles. Assume the falling water and geothermal are already mostly developed as much as they are going to be. So assume we are stuck with solar and wind power, but we can use biomass to liquid fuels, not driven by combustion of the biomass, but by external power generated by solar and wind.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>With those assumptions, what does a fully sustainable energy balanced planet look like? If you just take the total energy production and replace it all with solar, it comes out to something like 2e13 meters square of PVs, but I need to revisit that calc because my memory has grown dim regarding how I derived it over a decade ago. A huge factor is how we will do food: will we assume some means of turning solar energy into food other than putting it through plants?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>spike<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>-----Original Message-----<br>From: spike <<a href="mailto:spike66@att.net">spike66@att.net</a>><br>To: 'ExI chat list' <<a href="mailto:extropy-chat@lists.extropy.org">extropy-chat@lists.extropy.org</a>><br>Sent: Sun, 23 Dec 2012 6:03<br>Subject: [ExI] eroei forward for kennedy, p.e.<o:p></o:p></span></p><div id="AOLMsgPart_0_a5bf2505-2e45-4d0a-b9c0-8815ea92c5c5"><pre style='background:white'><tt><span style='color:black'><o:p> </o:p></span></tt></pre><pre style='background:white'><tt><span style='color:black'><o:p> </o:p></span></tt></pre></div></div></div></body></html>