Wind Turbines: No Bang For The Buck?

My rule of thumb is 60 acres per megawatt for wind farms on land.

— Tom Gray, Director of Communications and Outreach, American Wind Energy Assocation

There have been serious questions raised in Maine as to the costs and revenues of wind turbine facilities large and small. Actual financial performance apparently has not been revealed to any substantive extent. Not only is this rather baffling- wouldn’t the wind producers want people to know how well they are performing- but also, there would seem to be some requirement at least in the public arena for a degree of transparency in these matters. After all, a large percentage of the investment capital is coming from the taxpayers.

Perhaps the financial performance figures will remain cloistered until such time as public outcry forces these data into the open. However, it is simple now to evaluate wind turbine performance in terms of power rating versus land use, specifically, by evaluating output to land area affected by noise pollution for various power generation systems.

From a noise pollution viewpoint, an ideal power generation system is efficient, producing very little noise and vibration as waste by-products; or, it is a good neighbor, being quiet by design or incorporating noise controls to limit off-site noise pollution. For the same output, a wasteful design requires more land area or distance to reach a low enough noise level to be a good neighbor.

In the chart below, nuclear, fossil (coal, oil, natural gas) and wind turbines technologies are compared. It should be evident that the nuclear designs show by far the highest efficiencies, with the shortest distances and the largest outputs. Wind turbines on the other hand, appear to be by far the most inefficient from a noise pollution and land use standpoint, requiring substantial distances with meager power output compared to their nuclear and fossil counterparts.

Note: This chart was produced by scaling sound level versus distance for each power plant surveyed. No adjustments were made for plant capacity factors; with wind far lower than nuclear or fossil, we would expect increased vertical spread between wind and other technologies. Neither was adjustment made for tonal or short duration repetitive sound (SDRS) components as sound character data were not available for the nuclear and fossil units, only sound level in dBA at 1000 feet. Since nuclear and fossil plants tend to produce steady state noise, and wind turbines surveyed in Maine display tonal and SDRS components, one could expect that the nuclear and fossil plants require less distance to be good neighbors than shown on this chart. Thus both capacity factor and sound character would serve to increase the disparity in land use efficiency between wind and other plant designs.