By David Herres
Wind, the motion of air with respect to the earth’s surface, is a potent source of energy that may be harvested. Our ancient ancestors built sailboats powered by wind that crossed navigable waters and measureless seas. At first they went only a cautious distance offshore, primarily along coastlines. Eventually, seafarers crossed vast expanses of saltwater, discovering new continents.
A later use of wind power was for agricultural and industrial processes. It was found that grain could be ground, water pumped out of mines, lumber sawed, and so on. It was possible with available technology to build a rotor that would turn when there was sufficient wind.
In the nineteenth century, from a modest beginning, electrical power developed to a point where it played a key role in industry, agriculture and in the home. By 1900, single- and three-phase motors were everywhere that electrical distribution lines could be found.
Typically, electrical generators were made to be turned by steam-powered turbines run by coal-fired boilers. A significant amount of electrical energy was hydro-powered. Other energy sources were proposed, and wind power was correctly seen as a viable alternative.
In the course of the twentieth century, from modest beginnings, increasingly larger, more powerful and numerous wind turbines have contributed a significant portion of stand-alone and grid-connected power. Currently, reliance on fissile fuel is seen to have a whole spectrum of downsides, and to be the principle culprit in our environmental woes.
Proponents of utility-scale wind generation have made a strong case in favor of large wind farms with huge machines situated in flat fields or located along high ridges. But large-scale wind installations have become controversial. The primary objections are aesthetic, because these big machines block scenic views. A further objection is noise pollution, which is bothersome in the extreme for some nearby residents A good solution seems to be to locate the towers offshore as far as practical. As opposition on aesthetic grounds diminishes, construction costs soar. That is the price of doing business.
A future article will discuss some of the electromechanical challenges in building and maintaining these large structures, and we’ll find out a little bit about how technicians and engineers confront the challenges involved.