New Paper: Large Wind Farms Generate Far Less Energy Than Thought

  • Date: 26/02/13
  • Science 2.0

Wind farms may not generate as much wind power as thought. A new paper on mesoscale atmospheric modeling in Environmental Research Letters finds that the generating capacity of very large wind power installations is far less than previously estimated.

Activists love wind power the way they once loved ethanol and natural gas – it is good until scientists show them it is not.

Claims that there is no upper bound for wind power, that it is scalable because gusts and breezes don’t seem likely to “run out” on a global scale, are not based on reality.  And neither are claims that the generating capacity of large-scale wind farms is unlimited.

A paper on mesoscale atmospheric modeling in Environmental Research Letters instead found that each wind turbine creates behind it a “wind shadow” in which the air has been slowed down by drag on the turbine’s blades. The ideal wind farm strikes a balance, packing as many turbines onto the land as possible, while also spacing them enough to reduce the impact of these wind shadows. But as wind farms grow larger, they start to interact, and the regional-scale wind patterns matter more.

The generating capacity of very large wind power installations (larger than 100 square kilometers) may peak at between 0.5 and 1 watts per square meter. Previous estimates, which ignored the turbines’ slowing effect on the wind, had put that figure at between 2 and 7 watts per square meter.

In short, we may not have access to as much wind power as thought.

“One of the inherent challenges of wind energy is that as soon as you start to develop wind farms and harvest the resource, you change the resource, making it difficult to assess what’s really available,” says co-author Amanda S. Adams, assistant professor of Geography and Earth Sciences at the University of North Carolina at Charlotte.

Having a truly accurate estimate matters when taxpayer subsidies are being funneled into carbon-neutral energy companies.

Full story

 see also:  Rethinking Wind Power

The latest research in mesoscale atmospheric modeling, published February 25 in the journalEnvironmental Research Letters, suggests that the generating capacity of large-scale wind farms has been overestimated.