Wind power is abundant and

does not cause global warming

Cristina ArcherUniversity of Delaware

MARACOOS annual meeting, Baltimore,1 November 2012

Forbes.com

Wind turbines32 m blade of a 1.5 MW turbine

Hub height:80 to 100 mRated power:1-5 MW

Global simulationsGATOR-GCMOM model, a one-way-

nested global-to-regional Gas, Aerosol, Transport, Radiation, General Circulation, Mesoscale, and Ocean Model;

47 vertical layers (5 intersecting rotor swept area);

Coarse resolution (4ox5o); 4-years simulations (2006-2009).

Global simulations – continued

Power curve of REPower 5 MW turbine inserted directly in code

100-m winds, no extraction of energy by wind turbines

Mean wind speed ~ 8.1 m/s

Equations for extracting energy from wind via turbines

Kinetic energy DE extracted from a wind turbine over time step Dt:DE(t) = PEXTR(V(t)) x DtNew wind speed v at (t+Dt):

PEXTR=instantaneous power extracted from wind via turbine power curveM=mass of air in layer

Wind power and speed with turbines everywhere on Earth

Number of turbines = 1,200 MillionsTotal extractable power = 253 TW

Mean wind speed ~ 4 m/s

Wind power and speed with turbines over land only

Number of turbines = 300 MillionsTotal extractable power = 80 TWMean wind speed ~ 7 m/s

Wind power from 4 million turbines in three selected configurations

7.4 TW

2 TW4 TW

Global/Land saturation wind potentials

Jacobson and Archer (PNAS, 2012)

Global/Land saturation wind potentials

Jacobson and Archer (PNAS, 2012)

Theoreticalwind power potential

Practicalwind power potential

70

Wind turbine parameterization

Our turbine parameterization reduces winds at hub height and accounts for correct momentum extraction;

Roughness parameterization incorrectly reduces winds most at the surface.

Jacobson and Archer (PNAS, 2012)

Wind turbines reduce evaporation and surface temperature

Turbines slow surface winds, reducing evaporation, warming ground at first but reducing latent heat release, cooling the air. The reduction in water vapor, a greenhouse gas, cools the air and ground further.

The Cape Wind met tower

X

60 m

41 m

21 m

Unique marine conditions?

Unique marine conditions?

The Cape Wind met tower today

Cost estimate toreplace arms:<$300K

ConclusionsRenewable energy is the only way to stop

pollution, global warming, and ocean acidification and to provide endless energy;

Wind power potential is >250 TW (colossal);Wind power extraction can potentially impact

global climate, but only at colossal extraction rates;

At scale of global energy demand (~10 TW), wind power extraction does not cause climatic effects;

Cape Wind could become unique met/ocean research platform for <$300K. HELP!!!