Comments for The Seventh Fold

Comment on Forget about electric cars, behavioral changes offer the most efficient road to fuel savings! by The Seventh Fold

The Seventh Fold — Fri, 18 May 2012 16:31:06 +0000

Your points are well taken, but I was, in fact, only talking about city driving, as I indicated by the statement, ” What it describes (albeit poorly) is where energy is lost in your typical urban driving experience.”

The energy losses during highway travel are largely due to wind resistance, which increases as a cube of frontal area, I believe. Inertia works for you on the highway… unless, of course, you need to suddenly slow down.

During the urban driving experience, which involves much acceleration and deceleration, inertia works against you, and the mass of the vehicle, cargo, and occupants is by far the most important factor, and since speeds are far lower (at least they *should* be!), wind resistance is not a major issue.

Thanks for the thoughtful comment.

Comment on Forget about electric cars, behavioral changes offer the most efficient road to fuel savings! by Ok

Ok — Fri, 18 May 2012 07:39:17 +0000

These ratios might be true for rush hour city driving with a Hummer. But when long distance commuting the weight of the average car is not really the problem. Once it is rolling it is rolling. For example if you loaded up a Ferrari with an extra 1000 kg it would only decrease the top speed with only 10-20 km/h. And look at motorbikes, even though some of them weigh only 150 kg, which is 10 times less than your average car, they do not use 10 times less fuel. Maybe when you compare the smallest bike with the biggest car you save 10 times less fuel, but not with the average car. The most efficient highway capable bikes and scooters have a fuel economy of 120 mpg or 50 km/L. An average 4 cylinder car weighing 1500 kg uses about 40 mpg or 16 km/L. 120/40 = 3. So 10 times the weight but only 3 times the fuel efficiency. This means that friction has way more influence on fuel economy than weight.

Comment on Shale Gas is a Giant Loser! by ShaleStuff.com (@shalestuff)

ShaleStuff.com (@shalestuff) — Mon, 30 Apr 2012 13:56:06 +0000

What a great write-up on shale issues. I am researching the site ShaleStuff.com for a writer there anyhow and I think it is difficult to determine any of the facts when you have two distinct pools of scientists working on the evidence, one party working for the Greens and the other for the Energy Industry shaping the facts to match their narrative. I think the general public wants to know what the true cost is. They are not all idiots and know that any industry will bring some kind of environmental impact, the question is how much? what are the safely measures in palace? what is in it for me? my family, my community, my county my state? Is it worth it? Anyhow the site I work for is dedicated to the Communities Impacted By The Shale Gas Drilling Industry and we have been covering these fracking shale gas issues from center. It written in short easy to digest bites . It has all kinds of information about shale drilling, jobs, news. http://shalestuff.com/ check it out and let me know what you think..

Comment on 1/9/2012 Newsfeed by yellow freight

yellow freight — Thu, 02 Feb 2012 03:32:52 +0000

I’m looking at some statistics for air freight traffic and air traffic is differentiated into general aviation and certified route air carriers. I was wondering whether most air freight is shipped using certified route air carriers, or whether a significant portion is shipped using general aviation.

Comment on Peak Oil 101 by Brittany

Brittany — Fri, 21 Oct 2011 16:27:00 +0000

I really enjoyed reading this. It makes me nervous about what it is going to be like when I have kids.

Comment on EROeI and Net Energy by Gerald Glendenning

Gerald Glendenning — Thu, 25 Aug 2011 23:47:00 +0000

What is the EROeI for hydrofracking?

Comment on Update on the (un)economics of shale gas by Steve C in PA

Steve C in PA — Thu, 25 Aug 2011 19:00:46 +0000

Derek – looks like Art’s re-evaulation is being confirmed. The USGS cut its original estimation of recoverable natural gas by a factor of four (“Geologists Sharply Cut Estimate of Shale Gas” – NY Times, 24-Aug-2011). Also – what about another unitended consequence of fracturing: an increase in seismic activity. Was the recent Virgina 5.8 magnitude earth quake related? We’ll never know for sure. But that was an unpleasant experience (here in eastern PA – 250 miles north of the epicenter) and living and working in buildings not designed to withstand such tremors, not to mention the various aging nuclear power plants dotting the east.

Comment on Hubbert Linearization Debunked? by Greg

Greg — Thu, 21 Apr 2011 13:52:13 +0000

Hello:

Excellent analysis!

I would like to know what the world production curve would look like if:

(1) The exponential fit was true
(2) The logarithmic fit was true

It is bell-shaped, like a linear fit would give?

Comment on Reservoir Characteristics by tseaga

tseaga — Fri, 01 Apr 2011 20:18:49 +0000

greet job

Comment on About the Blog by Bill Bradburd

Bill Bradburd — Tue, 25 Jan 2011 06:42:05 +0000

yes – you are scheduled for Feb 26th!

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