Solar radiation evaporates water and creates temperature differentials across the globe. This moves moisture and air over the Earth’s surface, resulting in wind, precipitation, and rivers. Wind power has been used by humans for thousands of years: pushing boats, turning windmills, and powering modern wind turbines. Opponents of large wind turbines claim they kill birds and cause a low, constant, bothersome grumble. Cats and communications towers kill 6,000–10,000 times and 18–32 times more birds than wind turbines, respectively, and on a per-gigawatt-hour basis, wind turbines kill ten times fewer birds than fossil-fuel power plants.i Furthermore “wind turbine syndrome” has been linked to self-inflicted psychological stress, not physiological triggers, dismissed as a “nocebo” effect by the public health community.ii
Nevertheless, large wind turbines may not be an ideal long-term solution as they require complex manufacturing and maintenance. Furthermore, they are rather centralized and if a large turbine goes down, it would have wide-ranging effects. Although smaller wind turbines are less efficient, they are decentralized and can be built at home. Depending on where one lives, wind power might be a steadier alternative to (or partner with) solar. We might also revert to using wind power as kinetic energy instead of to generate electricity. For example, a geothermal heating system typically relies on an electric pump to circulate water, however a wind turbine could also perform that function.
Once on the ground, precipitation heads downhill,forming rivulets, streams, rivers, lakes, and oceans. The downward flow of water represents a huge amount of potential energy. Hydroelectric dams are the dominant way that industrial societies use flowing water to generate electricity. Damming a river is seen to provide not only power but to regulate the seasonal ebb and flow of a river, averting spring floods and late-summer droughts. Unfortunately, the unforeseen (or underappreciated) consequences of damming rivers appear now to outweigh the benefits. While the carbon-free energy generation is appreciated by the public, dams wreak havoc on regional ecological systems. By creating human-made lakes, streams slow and deposit their sediment upstream. This has had adverse effects on deltas and estuaries that depended on a constant influx of sediment. The Nile and Mississippi Deltas are receding, and in the case of the latter, reducing the protective buffer the wetlands offered against hurricanes. The water coming out of dams is from the bottom of the water column and thus much colder than the conditions under which the local ecosystem has evolved, causing problems for fish, plants, reptiles, amphibians, birds, and mammals. Aquatic animals that depended on traversing the length of a river are forced to adapt or die when a dam is built. The annual flood was a regionally important event but, in an effort to protect human property, it has been stemmed. Instead of moderate annual floods, we now experience periodic extreme floods, which is especially damaging to people who have built in locations made safe only by the illusion of safety given by dams and dikes.
Small-scale water power is a sustainable way forward. Unlike modern large dams, small waterwheels are not a centralized power source. If made without dams, a small waterwheel can convert flowing water into a modest amount of electricity or kinetic energy. Tidal movement and waves can rock energy-generating buoys without significantly impacting the environment. If one is located near flowing water, skimming a little energy without impeding the river’s course is a reasonable proposition.
We would be remiss if we failed to mention the use of geothermal energy to heat and cool indoor spaces. Although not currently used to generate electricity or other forms of power, the relatively constant temperature of the Earth’s crust can be harnessed in a low-power system to cycle cool water into hot summer homes and warm water to fight the winter chill. In addition to pipe-bound systems, houses could be built into hillsides or underground to take advantage of the ground’s thermal inertia directly. As noted above, building with energy use in mind (especially heating and cooling) is a prime way to decrease the amount of power needed to live comfortably.
i Erickson, Wallace P., Melissa M. Wolfe, Kimberly J. Bay, Douglas H. Johnson, and Joelle L. Gehring. 2014. “A Comprehensive Analysis of Small-Passerine Fatalities from Collision with Turbines at Wind Energy Facilities.” PloS ONE 9 (9): e107491.
Sovacool, Benjamin K. 2013. “The avian benefits of wind energy: A 2009 update.” Renewable Energy 49:19–24.
ii Crichton, Fiona, Simon Chapman, Tim Cundy, and Keith J. Petrie. 2014. “The link between health complaints and wind turbines: support for the nocebo expectations hypothesis.” Frontiers in Public Health 2 (220): 1–8.