ran an opinion piece recently that argued that self-checkout at the grocery was a failure. I can't argue with some of the author's complaints; for example, it takes somewhat longer because I have to look up some of the fresh produce codes that the experienced checkers know by heart. But I'm going to take strong exception to one of the advantages credited to human checkers, and that's the human checker packing the bags. Or more likely where I live, a dedicated teenager doing that job.
I have high standards for packing bags. One bag, usually, since I have a bloody great reusable canvas bag that I carry for the purpose. I learned bag packing by watching a master. When I was a graduate student in Texas, I rode my bike to campus almost every day and stopped at the little neighborhood grocery for whatever was on my list every couple of days. The old lady that checked me out and packed my bag always got everything in a paper bag with handles that I could hold with one hand while I gripped the handlebars. Every item, every time, one bag, nothing crushed. On rare occasions she would take some things out and repack them, but not often. She was amazing. I was studying applied math at the time and was always tempted to tell her, "But don't you know that the knapsack problem is supposed to be hard?"
I'm familiar with the dimensions of my bag. Before I start packing I look at the stuff and make a plan based on their shapes . I can put a relatively large amount of stuff in it -- far more than the teenaged bag-packers ever seem able to manage. It's sturdy and I'm still relatively fit, so I don't mind that it weighs 25 pounds some days. The kids are even worse about the plastic film bags that they put the overflow in. I got frustrated enough one day that I emptied the bags they had packed for me -- my canvas bag plus three plastics -- and put it all in the canvas bag.
I go through the self-check lines because I get to pack my own bag. It's a feature, not a bug.
 There are a few exceptions that don't go in the bag. If I have an eight-pack of paper towels, I carry it separately in my other hand, as it would pretty much fill the bag by itself.
Photo credit: Bloomberg News
Tuesday, October 1, 2013
Oil shale should not be mistaken for the tight oil (often called shale oil) whose production from the Bakken formation in North Dakota and the Eagle Ford formation in Texas has been hailed in some quarters as putting the US on the path to becoming self-sufficient in petroleum again. Those formations are producing actual oil; the oil shale formations in the Green River Basin in Colorado, Utah and Wyoming are rock containing substantial amounts of organic matter (kerogen) that can be turned into something like oil if you bake it for long enough at high enough temperatures. People have been trying to find some way to produce commercial quantities of near-oil from the oil shale for over a century (unsuccessfully to date).
Most (but not all) of the current generation of proposals for baking the kerogen use large amounts of electricity. As noted by the Denver Post's announcement of the Shell closure, such schemes would require the construction of one or more very large power plants. IIRC, at one presentation at the Colorado School of Mines, Shell engineers suggested that a million barrel per day operation would require about the same amount of electricity as currently generated in Colorado. That's a real problem, given the semi-arid climate and lack of population out in that corner of the state. Nukes are politically unpopular; other thermal generating technology would require cooling water (or accept lower efficiencies); intermittent renewable resources are a problem for the technology, at least in my mind. And there's no other customers for the electricity if the oil shale efforts don't pan out.
Hopefully the lesson that Shell and Chevron are teaching here are not lost on the group of politicians who continue to clamor for opening more federal land for developing oil shale. This is a crappy energy source, ladies and gentlemen. The experts are unable to produce oil-like liquids from it on a commercial basis. As a solid fuel, it's so bad it makes lignite look good. As both Shell and Chevron have indicated, there are better places to put your time, effort, and money.