In The Field

AGU: And the winner is … Wind!

This according to Stanford University researcher Mark Jacobson, who has compared various energy technologies in terms of not only greenhouse gas emissions but also conventional pollutants, land use, water resources and more. Speaking after a news conference here, Jacobson said he is trying to provide a more holistic analysis of the various energy options. “There’s a lot of misinformation out there,” he said.

A few of the key results follow:

Life cycle emissions — Wind and solar thermal come out on top; tidal, wave and hydro all beat out solar photovoltaics, geothermal and nuclear, thanks to energy spent on equipment and installation; coal was the big loser, even with carbon sequestration (CCS), thanks to energy spent on mining and transport.

Mortalities due to air pollution from US vehicles — For gasoline, projected deaths drop from 20,000 to 15,000 annually in 2020 due to improved technology and air quality standards. That figure would remain steady or perhaps even rise if ethanol (corn or otherwise) made up 85 percent of the transport fuels. Assuming electric transport takes off, wind reduces mortalities to almost zero, although the full suite of renewables fared almost as well. Coal with CCS would cut mortalities by upward of two-thirds. Nuclear falls between coal and renewables (assuming non-proliferation regimes hold and there aren’t any explosions).

Footprint required to power US vehicle fleet — Accounting for the base of the turbine alone (not roads), wind could power the entire vehicle fleet using less than 3 square kilometers of land. Corn ethanol and concentrated solar power are the big losers, with each requiring a chunk of land that is larger (and perhaps significantly larger) than the state of California.

Water usage — Wind, solar photovoltaic, geothermal, tidal and wave all come in around zero; coal, nuclear and concentrated solar do well; hydropower gets a poor rating, thanks to evaporation rates from reservoirs (Jacobson divvies up the losses among energy and other uses). But the clear loser is ethanol, whether the source is corn or something else.


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