Profs: Massive use of wind turbines WON'T destroy the environment
Would destroy the economy, though
Don't worry, we can solve the economic problems - literally with hot air
Then, in order to deal with the wind dropping on one continent as it sometimes does we need to be able to pipe in juice from around the world using unprecendented, planet-girdling interconnector power lines (or alternatively we need a vast pumped-storage infrastructure. When wind power reaches these kinds of levels, such relatively minor factors as millions of future electric vehicles plugged in for charging, fridges turning off for a bit etc simply can't help enough.)
It's hard to say what all this would cost as nobody has ever even attempted such things: but we might reasonably think of multiplying our $12tn cost figure a few times at the very least. And given the outrageous amounts of energy-intensive concrete, steel, copper and neodymium that would be required, the idea of doing all this while simultaneously reducing energy demands seems almost comically unrealistic. For instance, US government figures (pdf) suggest that just getting to 50 per cent wind energy (not merely electricity, but the ten-times-greater all-energy requirement) for the USA by 2030 would require something in the region of tripled US consumption of steel, concrete and copper, and multiplication of neodymium supplies many times over. As large amounts of thermal energy are used to make all these things, energy consumption would climb significantly - not fall.
Bearing in mind that the gross domestic product of the entire world is only $69tn (and this would probably contract drastically with the energy scarcity mandated by the IPCC and the two professors - indeed, modern hard-green thinking actually requires the goal of economic growth to be abandoned) we can safely say that 50 per cent energy from wind power is wildly unaffordable, and that the term "practical" isn't being used here in the sense that most people understand the word.
To be fair, however, one should note at this point that Professor Archer has a different plan for coping with windpower's can't-do-baseload problems. Rather than the conventional long-haul interconnectors or pumped storage as favoured by most windpower advocates, she also offers the idea of storing unused wind energy in the form of compressed air for use during calms or demand spikes. Earlier this year she teamed up with a Dr James Mason to look into this. (Dr Mason is not an academic of Archer and Jacobson's standing - both of them hold engineering and atmospheric-science degrees, and both work at respectable universities. Rather Dr Mason is employed at a Heartland-Institute-style nonprofit advocacy organisation called variously "American Solar Action Plan", "Hydrogen Research Institute" etc, and his degrees are in "environmental sociology" and "economic sociology".)
Compressed-air experimental installations are being constructed at present in both the US and Germany, with the idea of using such tech as a means of power storage to help make renewables viable (perhaps reflecting the serious doubts regarding interconnectors, and the undeniably titanic costs and limited capabilities of pumped storage). In power-grid applications, the air would probably be kept in suitable underground geological formations rather than in tanks as seen on the long-hoped-for but disappointing pneumatic cars.
One should bear in mind that compressed-air plants still need to burn fossil fuel (generally natural gas) to prevent the air freezing too much as it expands, which causes unacceptable inefficiencies. In fact a compressed-air storage plant used to back up intermittent wind can be expected to burn a quarter of what a normal gas-turbine plant would when doing the same job, so this is not fully green like interconnectors, pumped storage etc.
But it is potentially far less costly, perhaps requiring a mere doubling of gas prices before it becomes able to compete with straightforward gas turbines in the matter of backing up wind as happens today. Archer and Mason write:
The large-scale introduction of Wind-Compressed Air Energy Storage systems in the U.S. appears to be the prudent long-term choice.
Or if you don't like that idea, perhaps you might go for another of Professor Archer's plans, that of flying mighty windpower kites attached to high-voltage power cables up in the high altitude jet stream (though funnily enough Archer's opponents at the Max-Planck Institute in Germany say (pdf) that that idea's a non-starter as well, both on limited power output and serious damage to the climate. Again, it's hard to say who's right on the atmo-physics.)
There's evidently a good deal of uncertainty regarding the level at which wind power starts to damage the atmosphere the way carbon emissions are thought to. Another paper just out from hefty atmosphere scientists at the Lawrence Livermore lab and the Carnegie Institution says:
We find wind turbines placed on Earth’s surface could extract kinetic energy at a rate of at least 400 TW, whereas high-altitude wind power could extract more than 1,800 TW. At these high rates of extraction, there are pronounced climatic consequences. However, we find that at the level of present global primary power demand (~ 18 TW), uniformly distributed wind turbines are unlikely to substantially affect the Earth’s climate. It is likely that wind power growth will be limited by economic or environmental factors, not global geophysical limits.
"Uniformly distributed", as we've noted above, means "even more unbelievably expensive than you thought". However it would seem that actually harming the planet may not be an issue for windpower up to a point, and if Jacobson et al are right this point is well above any likely human power demand. It also seems quite plausible that a lot of power is there to be had if one is able to cover the entire world in wind turbines and associated roads, power lines etc.
What's not at all plausible, however, is that the necessary infrastructure can be built and made to deliver any reasonably comfortable level of power to the human race at any cost the human race can afford. ®
Professor Archer is essentially one of Professor Jacobson's acolytes. Jacobson himself is one of the modern breed of crusading STEM academic. He doesn't set out asking himself questions like "what's the best way to generate low-carbon electricity?", he asks "how can I make wind look good and nuclear look bad?"
This has led him in the past to argue that nuclear power is actually more expensive than wind, an idea widely rubbished by other researchers - even very greenly inclined ones. He has also flown in the face of the scientific consensus in other ways: the consensus says that the Fukushima reactor meltdown will not cause any measurable health effects, but by Jacobson's calculations it will probably cause several tens of deaths from cancer - or even more - over coming decades. (Other boffins found this disingenuous enough that they felt it worthwhile to point out that had Fukushima never been built and the same amount of power instead been generated by fossil-fuelled means, more people would have had to die as a result. Solid figures on the dangers of windfarms are not available due to the fact that they have not generated enough power yet, but all the indications are that they are many times more deadly than nuclear powerplants, so Professor Jacobson plainly isn't worried about a certain number of deaths as such - he just doesn't like nuclear power.)