Sustainable Energy Without the Hot Air by David MacKay

What does a world without fossil fuels look like?  There are lots of different options, but none of them look much like the rich developed nations of the world today.  David MacKay’s approach in Sustainable Energy Without the Hot Air is to hold our rate of energy consumption constant, and explore the kinds of carbon-free energy systems that could satisfy that demand.  The uncomfortable conclusion he comes to is that if we want to run our world on renewables, the energy farms have to be comparable in scale to nations.  Comparable in scale to our agricultural systems.  This is because all renewable energy is very diffuse, and we use a whole lot of energy.

SunPower's Bavarian PV Installation

Just as an example, of all the renewable power sources solar is the most concentrated, and PV farms like the ones cropping up in Bavaria because of Germany’s generous feed-in tariff average about 5W/m2.  With better siting (the Sahara, Arizona) you can do a bit better, and there’s a little more efficiency to be eked out of the panels, but for large scale deployments, you’re not going to get above 10W/m2.  If you’re an average citizen of the EU or Japan, your 5kW of power thus demands 500m2 of land.  Multiply that by 700 million people in the EU, and you get the total area of Germany.  An average North American’s 10kW requires 1000m2.  Multiply that by 300 million people, and you get an the entire area of Arizona.

Continue reading Sustainable Energy Without the Hot Air by David MacKay

Why Urban Farming is an Awful Idea


Boulder County is looking at some kind of county-wide sustainability program, with an associated tax which will be on the ballot this fall.  The City of Boulder is revising its Climate Action Plan, looking toward a goal of climate neutrality in 2050.  An extension of the tax which supports our climate work will also be on the ballot in the fall.  One thing that none of that money should go toward?  Urban farming.

Continue reading Why Urban Farming is an Awful Idea

Empirical Investing

In my previous post I described the stock and bond markets by analogy with a casino, but you might reasonably question the validity of that analogy.  Are market returns really as unpredictable as coin flips?  The real payoff probability distributions obviously aren’t binary; what do they actually look like?

Continue reading Empirical Investing

Links for the week of November 20th, 2009

If you want to follow my shared links in real time instead of as a weekly digest, head over to Delicious. You can search them there easily too.
Continue reading Links for the week of November 20th, 2009

Shared Links for Jun 26th – Jul 7th

You can also search or subscribe to my linkstream over at Delicious.

Shared Links for Apr 17th

Shared Links for Apr 8th

  • The secret, social lives of bacteria – Cooperative behavior between bacteria, both inter and intra species, coordinated via chemical messages. Behavior like "should we make light?" and "should we kill the host now?". Scary, awesome, and a beautiful system to investigate with algorithmic game theory! (tagged: cooperation biology technology bacteria science )
  • Computational Legal Studies – More people using machines to understand politics. A whole new class of dual use technology. Propaganda or transparency? Manipulation or clarity? Unauthorized social networking. (tagged: transparency technology government law )
  • Public Private Investment Partnerships a la Enron – Giving banks the ability to both buy and sell into the toxic asset markets being set up under PPIP is a recipe for market gaming in the tradition of Enron, as outlined in this example. Great, a trillion dollar Enron! (tagged: finance bailout economics policy enron ppip banks )
  • The New Nostradamus – Bruce Bueno de Mesquita uses large game theory simulations to try and predict the outcomes of complex negotiations involving many parties, both economic and political. Sounds interesting. Also sounds a little bit like bullshit. But apparently the CIA did a prospective trial (no backtesting bias) and found that the models made accurate predictions something like 90% of the time, when the analysts providing the inputs to the model made wrong predictions. Not so surprising that computers are better at synthesizing massive logical datasets into an outcome. The hard part seems like it would be getting the right inputs, and also trusting that people behave rationally, and (perhaps) know what's good for them. (tagged: economics politics science math prediction gametheory technology )
  • Ice Shelf Instability Backgrounder – A good backgrounder from last summer on the Wilkins Ice Shelf (which has just collapsed), and shelf dynamics in general, with links to the relevant literature. None of this is quite as sudden and shocking as the media reports have made it out to be. (tagged: climate antarctica ice shelf )