What’s happened to acid rain?
If we don’t see it in the news, does that mean it has gone away?
Dear Control Engineering: How come we never read about acid rain in our newspapers anymore? Not even in Minnesota, land of 10,000 tree huggers. Tom D., retired control engineer.
As the graph from the U.S. EPA shows, acid rain reductions are a success story in that the amount has indeed declined for a number of reasons. Most relate to coal use, as sulfur content is the primary source. Here are a few specifics:
EPA regulations have worked in that they have driven utilities to install scrubbers and other remediation strategies. The Economist pointed out that 53% of coal-fired generating capacity now has scrubbers.
Utilities are closing older plants. For example, FirstEnergy just shut down a group of old coal burners in Ohio, and there are more on the hit list in other areas. That will raise the proportion of plants with scrubbers.
Coal-fired generation is declining overall. Ten years ago, coal-fired plants accounted for 52% of our electricity. Now that figure is 45%, and predictions suggest that downward trend will continue as natural gas and renewables grow.
As the Economist article notes, there are many more costs related to producing and burning coal than most people realize. There are technologies to mitigate the problems, but these are generally only installed at newer facilities. Getting over the problems will take time, but you may have more trees to hug.
Peter Welander, firstname.lastname@example.org
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Annual Salary Survey
Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.
There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.
But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.
Read more: 2015 Salary Survey