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Americans spend less of their income on food at home than any other country

Via Marginal Revolution:

The food deserts idea was especially implausible for America because Americans spend less of their income on food consumed at home (6%) than any other nation. The Dutch, for example, spend (12%) of their income on food, the Italians and Japanese (14%), the Vietnamese (35%). There is plenty of room in the American food budget for healthy eating.


Electric vehicles might eventually be the future but..

Finally someone summarizes this point about not being misleading on electric vehicle efficiency:

  • When we say that electric motors are 97% efficient, we mean that the actual physical work produced per unit of time is 97% of the electrical power used by the motor, which equals the current flowing to the motor times its voltage.
  • When we say that the internal combustion engine is 45% efficient, we mean that the physical work we get out of the engine is 45% of the heat liberated from burning its fuel.

… Taking these numbers, let’s convert the 97% efficiency number for electric motors to an efficiency number all the way back to the fuel so it is apples to apples with internal combustion.  We take 97% times 90% transmission efficiency times 50% electricity production efficiency equals 43.6%.


The problem with all this is that most of the barriers to using electricity in more applications are not related to motor efficiency. For vehicles, the problem is in energy storage density. Many different approaches to powering automobiles were tried in the early days, including electric and steam powered cars. The main reason, I think, that gasoline won out was due to energy storage density. 15 gallons of gasoline weighs 90 pounds and takes up 2 cubic feet. This will carry a 40 mpg car 600 miles. The Tesla Model S 85kwh battery pack weighs 1200 pounds and will carry the car 265 miles (from this article the cells themselves occupy about 4 cubic feet if packed perfectly but in this video the whole pack looks much larger). We can see that even with what Musk claims is twice the energy density of other batteries, the Tesla gets 0.22 miles per pound of fuel/battery while the regular car can get 6.7. More than an order of magnitude, that is simply an enormous difference, and explains the continued existence of internal combustion engines much better than electric motor inefficiencies.

He’s not bashing electric cars he goes out of his way to point out where stats used might in reality be more in favor of electric cars, but this should be mandatory reading for having a discussion about electric cars, battery storage, and Tesla as such a high profile company.

Even Eric Schmidt (co-founder of Google, obvious genius) and the mostly excellent Economist trip over this. There are plenty of reasons to like electric cars and even all things being equal distributing air pollution out of inner cities is an advantage of electric cars but there’s a lot of common sense missing generally about how electric cars compare to combustion engines and doing reality checks on what subsidy programs are achieving.


Future of cities..

There are some really neat ideas emerging about the future of cities that for me make old ideas around New Urbanism interesting again.

This Econtalk podcast episode is a great discussion around the future of inner city driverless cars and the possibilities for taking back some of the space used for today’s average car size and parking.

And this is a quote of a quote from Alex Tabarrok but is nuts. From his post explaining how Google may be one-upping Amazon and considering building a city from scratch.

The world is building more cities, faster than ever before. China used more cement in the last three years than the United States used in the entire 20th century.

Exciting times to come.



Feedly mute filters sweet feature for RSS

My love for RSS goes back to using Google Reader + Yahoo Pipes to do some very cool things and so I was stoked to see this feature request marked completed.

Sounds like they’ve already soft launched this:

Some examples of why this is useful- makes boolean search triggers possible on sites with rudimentary search functionality like Kijiji, you could pair down all kinds of feeds that have way too much noise to pay attention to like local events feeds, and this essentially compliments Google Alerts by allowing you to do the opposite of using search triggers.



Taking your life back from technology

I’ve always been a reluctant consumer of twitter and social media in general, with a strong preference for RSS feeds that allow for batching incoming information. This was a very practical discussion of implications of social media addiction in the business world. Apparently the average American adult between 16-64 spends 3 hours / day on social media sites! At the very least the author is spot on suggesting one of the easiest decisions to make is to at least remove social media apps from your phone..

Cal Newport on taking your life back from technology

Check out if you’re stuck wondering how to get off the Twitter escalator but not lose some great content that gets posted there.

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