Aktualna izdaja prestižne MIT Technology Review poroča o študiji dveh raziskovalcev iz Harvarda, ki sta v analizi, objavljeni v akademski reviji Joule, demonstrirala, da denimo 100 % proizvodnja električne energije v ZDA z vetrnimi elektrarnami do konca tega stoletja ne bi zmanjšala temperature površja celinskih ZDA, pač pa bi prispevala k povečanju temperature za 0.24 stopinj Celzija. Avtorja zato pravita, da je potreben fokus ne samo na vetrne elektrarne, pač pa tudi na sončne. Sicer tudi sončne elektrarne prispevajo k segrevanju, vendar 10-krat manj kot vetrne.

Je pa pri teh ugotovitvah treba biti previden. Potrebno je upoštevati časovni horizont. Te ugotovitve veljajo v horizontu do konca tega stoletja. V daljšem časovnem horizontu, denimo na tisoč let, pa imajo “preprečne emisije CO2” z zamenjavo elektrarn na premog z elektrarnami na veter vseeno ugoden vpliv na ravni CO2 (in posledično temperature), ker je pri CO2 potrebno upoštevati učinek akumulacije.

Seveda sta avtorja s svojimi ugotovitvami naletela na številne kritike iz tabora zagovornikov vetrnih elektrarn. Najdete jih na spodnji povezavi.

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Wind power is booming in the United States. It’s expanded 35-fold since 2000 and now provides 8% of the nation’s electricity. The US Department of Energy expects wind turbine capacity to more than quadruple again by 2050.

But a new study by a pair of Harvard researchers finds that a high amount of wind power could mean more climate warming, at least regionally and in the immediate decades ahead. The paper raises serious questions about just how much the United States or other nations should look to wind power to clean up electricity systems.

The study, published in the journal Joule, found that if wind power supplied all US electricity demands, it would warm the surface of the continental United States by 0.24 ˚C. That could significantly exceed the reduction in US warming achieved by decarbonizing the nation’s electricity sector this century, which would be around 0.1 ˚C.

“If your perspective is the next 10 years, wind power actually has—in some respects—more climate impact than coal or gas,” coauthor David Keith, a professor of applied physics and public policy at Harvard, said in a statement. “If your perspective is the next thousand years, then wind power is enormously cleaner than coal or gas.”

Specifically, the “avoided warming” achieved by eliminating fossil-fuel sources could surpasses any warming from wind in about a century in the studied scenario, as emissions reductions accumulate.

Keith and lead author Lee Miller, a postdoc at Harvard, stress that the conclusions mean scientists and policymakers should take this side effect of wind power seriously—and carefully consider what role the resource should play in the shift to clean energy.

“Our analysis suggests that—where feasible—it may make sense to push a bit harder on developing solar power and a bit less hard on wind,” Keith said in an e-mail.

Notably, the warming effect from wind in the studied scenario was 10 times greater than the climate effect from solar farms, which can also have a tiny warming effect.

The core problem is that wind turbines generate electricity by extracting energy out of the air, slowing down wind and otherwise altering “the exchange of heat, moisture, and momentum between the surface and the atmosphere,” the study explains. That can produce some level of warming.