Wind power has emerged as the most cost-effective means to generate electricity. Already more than 20% of the electricity in Iowa and Texas is captured from the wind, and in either case you can bet that it wasn’t concern about climate change that has powered the transition.
Beyond basic costs, wind has a lot of advantages: no air pollution (unlike coal), no waste disposal (unlike nuclear), and no pipelines (unlike natural gas). If you are concerned about climate change, wind power emits no greenhouse gases to the atmosphere. About all you can say that is negative about wind power is the amount of land required for wind mills and its potential to cause bird mortality.
The land requirement for wind farms stems from the “wake” of turbulent air that affects the performance of wind mills that are downwind, although even that loss is not enormous, often about 5% of generation capacity. One study in China found that the wake effect was fully attenuated within 20 km. Within wind farms, the individual wind mills are usually placed not closer than five times the length of their blades to avoid the wake effect. And wind mills are best placed about 300 m from the nearest house to avoid any annoyance from their sounds.
Each year, generating energy from the wind typically requires 72 km2 of land per Terrawatt-hour, compared to 433 to 654 km2 for energy from biomass. Luckily, the land under wind mills can still be used for other purposes, such as cultivation and grazing.
No doubt, some birds are killed by collisions with wind mills each year, but substantial progress has been made in locating wind mills to reduce bird mortality. For the United States, overall mortality of birds by collisions with wind mills (340,000) is much less than for collisions with buildings (600 million/yr) and automobiles (340 million/yr), and dwarfed by predation from feral house cats (3,000 million/yr).
Although it is easiest, and therefore least costly, to develop wind farms on land, there is great potential for off-shore wind power, which potentially lowers bird mortality and offers fewer constraints for the spacing of large wind mills. One estimate suggests that for the United States, off-shore wind power could supply roughly four times the current consumption of electricity. Europe has embraced off-shore wind power for a couple of decades, and one study from the Netherlands indicates few impacts of wind mills on the marine community. Now, large wind power developments are in progress along the eastern coast of the U.S. New developments in battery storage should diminish the problem of intermittency in wind power generation.
When it comes to sources of power, off-shore wind development looks much more attractive than off-shore oil development, with its potential for seismic disturbances, leaks and spills. For generations, wind power provided energy independence for rural farms and ranches. Now it can do the same for entire nations.
References
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Environment America Research and Policy Center. 2018. Wind Power to Spare: The enormous energy potential of Atlantic Offshore Wind. https://environmentamerica.org/reports/ame/wind-power-spare-enormous-energy-potential-atlantic-offshore-wind
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One challenge is ensuring sufficient base load when the wind isn’t blowing. It’s a bit counter intuitive, but here in the Midwest, highest wind and generation capacity is at night. A great way to ensure sufficient base load is to combine wind – mostly night – with solar – exclusively daytime. The costs have really come down for wind and solar, so now is the time to embrace this renewable one-two punch!