Macro-Engineering and Renewables: Tilting at Windmills?

The renewable energy landscape features a few really giant ideas. Should that give us pause?

2 min read
Macro-Engineering and Renewables: Tilting at Windmills?

As we have covered in this space before, the Desertec Foundation wants to build massive solar thermal installations in the Sahara Desert and elsewhere, pointing out that if only a tiny fraction of the world's deserts were used we could have all the power we would ever need.

But that isn't the only instance of macro-engineering ideas in the renewable energy field: from T. Boone Pickens's ideas around wind power to proposed hydroelectric monstrosities in Africa, people have been thinking BIG when it comes to pushing fossil fuels out of the picture. Some of the ideas seem great, like the solar thermal plants in the desert; but given our general history with projects on such huge scale, is macro-engineering a new energy landscape really the way to go?

Take the idea put forth by researchers in 2007 of a massive dam at the narrow southern entrance to the Red Sea: the project would conceivably generate upwards of 50 gigawatts of electricity, but the authors themselves basically acknowledge such an idea is little more than a thought experiment. "The cost and time-scales involved are beyond normal economical considerations," they write, and seem more interested in simply discussing the implications of such huge projects.

But is that really so off-scale? The existing Three Gorges Dam along the Yangtze River in China (pictured) will peak at just shy of half that capacity, and the proposed Grand Inga Dam along the Congo River will supposedly have a generating capacity of 39 gigawatts.

Clearly, we as a species are not incapable of seemingly insane-in-scope projects, and renewable energy is no exception. Dams, of course, are public enemy number one among environmentalists when it comes to renewables, but is it possible that that's just because we haven't completed any really big solar or wind projects? Three Gorges displaced 1.3 million people, had cost overruns in the many billions of dollars, and has been threatened by such largely unforseeable problems as giant islands of garbage that could have jammed up the turbines.

What would Desertec do to the Sahara? What would happen to America's "wind corridor" through the Midwest if all of the Pickens turbines were actually built? Clearly, I am not suggesting that renewables aren't the most important energy source of the future (they are), only that thinking too big sometimes has unintended consequences. Macro-engineering concepts in other fields are often just ideas that don't get built:  the giant Shimizu Pyramid, or, say, a space elevator. With the need to massively expand renewable energy around the world growing greater with every ton of CO2 emitted, does it make more sense to focus efforts and dollars on individual, very doable projects than on giant quick fixes?

(Photo via Hugh/Wikimedia Commons)

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