Microwire Photovoltaics at Caltech

I went to this year’s second Everhart Lecture yesterday by Josh Spurgeon, who is working with Harry Atwater and Nate Lewis, trying to develop cheap, scalable solar cells.  As with most of the Everhart Lectures, it was a very well presented talk.  Unlike many of them, it was directly relevant to a real-world problem: how can humanity continue to utilize on the order of 10TW of power, without changing the composition of the atmosphere (see Nate Lewis’ excellent presentation for more information). The ultimate solution to that problem will almost certainly involve directly capturing incident solar energy, because the potential resource available is both vast and relatively concentrated, when compared to other sources of renewable energy.  But solar has two very serious problems today: it is expensive (both in absolute terms on a per watt installed basis, and in an up-front capital expenditure sense), and it is not available when the sun isn’t shining.  Whatever the solution looks like, in order to scale up to 10TW, it needs to use only earth-abundant, non-toxic materials.  In semiconductor photovoltaics then, silicon probably has an unassailable lead.  It’s the second most abundant element in the Earth’s crust, and it’s about as toxic as sand (though silicon semiconductor fabrication has serious toxicity associated with it and certainly needs to be made closed-loop).  Exotic materials like cadmium-telluride, and copper-indium-gallium-selenide (CIGS) are unlikely to scale to tens of terawatts, simply because of the limited availability of elements like indium and tellurium.  Additionally, owing to the vast silicon microprocessor industry, we are much better at micro and nano-scale manipulation of silicon than any other material on Earth (ignoring for the moment biological systems).

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Shared Links for Apr 28th

Have you seen the light?

As animals, and especially visual animals at that, we have a particular experience of the light.  For us it is illumination, information about our surroundings.  For that purpose moonlight or even starlight will do.  And for tens of millions of years, that’s all we ever saw.  Somehow a few of us made it through the Permian extinction, and into the Triassic, but the ascendancy of the dinosaurs eventually forced us into the darkness of the night.  Our world became dim, and our eyes went colorblind.  Most mammals today see only two colors, but a few of us have re-evolved a third photoreceptor.  Three colors is still inferior to the four or five or six seen by many near-surface fish, birds, reptiles, insects, and other arthropods.  The stomatopods are almost biological spectroscopic imaging systems, with 12 color channels in each of their independently movable trinocular eyes.  We are lesser than the eyes that never left the light.  They stole the colors from us and made us hide within the night.  They kept the sun for themselves, not knowing that our small and furtive ways, our burning endothermy and our fur would see us through the aftermath of the KT impact.

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Shared Links for Mar 14th

Shared Links for Feb 20th

Shared Links for Feb 19th

Shared Links for Feb 11th – Feb 12th

Shared Links for Sat, Feb 7th, 2009 through Tue, Feb 10th, 2009

  • Thefts puncture Paris bike scheme – More of Paris' Velib bicycles are being stolen or vandalized than expected. Not sure what their expectations were, but it is pretty annoying for basically every bike in the network to have been either stolen or damaged in only 18 months. The vandalism is probably impossible to stop (since it can be carried out while the bikes are locked in their stands) but the theft should be preventable with secure stands, and aggressive enforcement of responsibility for a bike while you've got it checked out (i.e. if the bike doesn't come back, your credit card is immediately charged for the total value of the bike, or possibly even more). I also can't help but wonder if the same functionality could be implemented with much, much cheaper bikes, especially in a city as flat as Paris. Singlespeeds with fenders and a basket, maybe 100 Euros each? With an RFID tag embedded – and put all the smarts in the racks. (tagged: bicycle bike cycling transportation paris velib )
  • Google Power to the People – Google developing tools to allow you to disentangle your own energy use, when the datastreams from smart meters come on line. Making this information easy to comprehend, pricing electricity to displace demand from the peak times, and allowing the largest energy users to schedule their use in an automated way could (without even changing anything physically) have a large impact on the amount of power generating capacity we (don't) need. (tagged: energy google sustainability green open data transparency )
  • WattzOn and Wesabe Join Forces – This is the post that made me wish the Elevations Credit Union was more internet savvy. I want to be able to apply all these big-brotherly tools to myself! (tagged: open data transparency energy wesabe wattzon money finance )
  • Numbrary – A library for numbers – mass quantities of publicly available data, mostly (entirely?) from the US Government. In a hopefully usable and searchable form. Many automatically generated charts and tables. (tagged: data transparency government statistics open )
  • Mayapedal – People building useful human-powered bicimaquinas, in Guatemala, where human labor is still a common prime mover: washing machines, coffee de-pulpers, corn de-grainers, grain mills, blenders, concrete microvibrators, etc. One kind of appropriate technology. There's also some YouTube videos on them, e.g.:

    http://www.youtube.com/watch?v=nrqbtUKpSjo (tagged: bicycle guatemala appropriate technology human power energy )

  • Humanity In Motion – An incredible montage of what bicycles can be: safe, enjoyable, cheap, convenient, everyday transportation for young people and for old, for families, in a city largely unpolluted by the exhaust and noise of cars. (tagged: bicycle transportation amsterdam netherlands photos )

Shared Links for Fri, Feb 6th, 2009 through Sat, Feb 7th, 2009

  • Overcoming Obstacles to U.S.-China Cooperation on Climate Change – Guidelines from the Brookings Institute for the US and China to cooperatively address climate change and clean energy issues, without being combative. Executive summary sounds good, whole thing is 80 pages long. Given the positive economics for many energy efficiency measures, I thought there should have been a little more focus on the often erroneous assumption that addressing these issues has to be costly. (tagged: energy sustainability china policy climate efficiency brookings )
  • Amendment to Eliminate Bike Infrastructure in Stimulus – DeMint (R – SC) and Coburn (R – OK) are trying to kill all bike infrastructure investment in the stimulus package. Call them and your own senators and make sure it doesn't happen! (tagged: politics bicycle infrastructure policy transportation stimulus )
  • The Transparent Society – The essay that later became Brin's book of the same name, in which he argues that first, universal surveillance is coming, whether we like it or not, and second, that a world which is transparent – in which surveillance goes both (all) ways, is vastly preferable to one in which the illusion of privacy is maintained, and the powerful are the only ones with access to our information. (tagged: technology privacy transparency surveillance brin wired )
  • Make Love Not Porn – Hardcore (esp. internet) porn has unfortunately come (ha!) to substitute for sex-ed in our culture, so says Cindy Gallop. I think she has a point. And so she made this website, to try and point out the flawed generalizations that one might arrive at from being "educated" by online porn. I think it's worth noting also though, that the diversity of pornography on the web has steadily increased over time, and there's a lot of positive and realistic, and non-exploitive depiction of sex out there now, if you want to look for it. In particular Abby Winters, Beautiful Agony, and I Shot Myself come to mind. It's ironic (absurd?) that the site has an "18+ only" clickthrough on the front page. (tagged: porn sex love ted education )
  • Dept. of Energy to draft energy efficiency rules… 30 years late. – I can't believe I'd never heard of this. Apparently for the last 30 years, presidents have been refusing to direct the Dept. of Energy to draft enforceable energy efficiency regulations, despite being directed under law to do so by Congress. Finally in 2005, 14 states sued, and won, and Bush still failed to comply in a timely manner. How many other instances of the executive branch (both democrat and republican!) completely ignoring Congress on important issues are there? It's rare enough that Congress gets anything right – that the president should ignore them when they do is unconscionable! (tagged: politics policy energy nytimes green efficiency standards regulation )

Shared Links for Thu, Feb 5th, 2009

  • First annual Letter from the Gates Foundation – I hate Microsoft, but in the great American tradition of evil corporate fortunes being given back to good causes, the Gates Foundation works on some difficult, important, and interesting problems. I've been curious exactly how and why their focus on population has faded away over the last few years. Not sure this letter (suggested by and modeled after Warren Buffet… who doubled their endowment last year) really answers that question. I get the feeling that the change is partly for PR reasons – that they remain focused on the issue, but don't think it's really productive to make that statement prominently. (tagged: philanthropy health microsoft bill gates population )
  • WRI on Bus Rapid Transit v. Light Rail – Given the difference in cost, I really don't understand why BRT doesn't get more consistent consideration in transportation planning. Hopefully someone will notice this study (and hopefully the study is done well…) (tagged: transit transportation brt rail sustainability bus green )
  • Bill Gates unplugged – Talked about two problems: malaria, and lousy teaching in America. Not so interested in Malaria (we know what we need to do, we just don't really care… and if all it does is increase human population, is that really a success?), but our inability to make teaching work well reliably is really annoying… (tagged: education ted teaching schools bill gates )
  • Till Children Do Us Part – Yeah, having kids can keep you together… out of obligation, or desperation if you're an unemployable 50s housewife. But jeez, who ever thought they actually help a marriage? (tagged: children marriage love )
  • Dumping the Refrigerator for a Greener Planet – Well of course I *could* do without a fridge if I wanted to, but why not just get a super-efficient one, or understand better what *actually* needs refrigerated, or design a fridge that takes advantage of the outside temperature for condensing or evaporating coolant, or build an insulated north-facing root cellar into your earth-sheltered house, or use a zeer evaporative fridge, etc. Story seems a little one dimensional. (tagged: refrigerator energy sustainability green environment efficiency )
  • Extended Producer Responsibility – I wonder just how much of my predilection for German bike parts comes from their EPR policies, and how much comes from the German design ethos, and how separable those two things really are? (tagged: bike germany green sustainability recycling policy bicycle )