Ask Control Engineering
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control and embedded systems. Control Engineering answers questions from readers of Control Engineering's print and online magazines, newsletters and other publications. To comment on any blog posting, click on the post's highlighted question and scroll to the "Post a Comment" box at the bottom. Submit questions as comments to any existing post.
Can we do without nuclear power?
Can we, as some suggest, shut down some or all our nuclear power plants? What will make up for that lost generating capacity?
Dear Control Engineering: After recent events in Japan, there are people calling for nuclear plants to be shut down forever. Is this even possible? Could we do without that much generating capacity?
One of the very practical considerations in the nuclear power controversy is if we can do without it. The answer to that question depends on where you are. World-wide, nuclear power generates about 14% of total output, but locally that number can vary drastically. France gets most of its power that way. The U.S. is more than 20%. More importantly, almost without exception, nuclear power plants are base loaded, meaning they run constantly at or near their capacity. Some plants modulate their output to reflect demand, but nukes run hard all the time. This means that any replacement technology has to be able to equal that.
Even the most enthusiastic anti-nuclear activists would be reluctant to suggest that coal-fired plants be built instead. There is the whole global warming thing and other classes of pollutants. Renewables are difficult if not impossible to use for base loading. So what is the alternative? Arguably the only practical one is natural gas.
If there is any country that has a high likelihood of actually shutting down its nuke plants, it’s Germany. The political climate there certainly points in that direction. A recent report by Deutsche Bank cited in The Economist reasons if Germany shut down all its reactors, it would have to build about 23,000 MW of new gas-fired capacity for base loading. That’s a lot, but not out of the question. Think of it as about a dozen two-unit plants. So where will all that gas come from? As it turns out, there is capacity in Europe and Russia that was developed to service the U.S. However, with our growing domestic production, we aren’t importing as much as we used to, so that output can be repurposed. Of course Germany’s annual carbon dioxide emissions will increase by several hundred million tons in the process. That’s far lower than it would be for coal, but it still isn’t free.
Peter Welander, pwelander(at)cfemedia.com