Wind and Solar Power Working in Tandem
There is much talk about alternative (or “green”) energy sources these days. Although there a several different types-ethanol, biomass, hydroelectric, and geothermal heat pumps, to name just a few-two types have risen to prominence in the political debates: solar cells and wind turbines. Opponents of these renewable energy sources point out that wind and solar power combined currently provides less than 1% of America’s energy needs. But don’t let this fool you. America’s capacity to harness these energy sources is rapidly growing. As more and more wind farms are being built, electricity generated by wind turbines has risen to two and a half times the amount produced just five years ago. Photovoltaic solar cells now generate sixteen times the amount produced ten years ago!
There’s a reason these two particular green energy sources have been growing so fast. Other green energy sources, like gas captured from landfills and hydroelectric dams, and limited by geography. There are only so many landfills to tap into, and a limit to the number of rivers that can be dammed. Geothermal heat pumps, solar cell arrays, and wind farms, in contrast, can be built almost anywhere. Sure, some locations are better than others-the Southwestern USA gets more sun and the Great Plains gets stronger, steadier winds-but the truth is the sun shines, the wind blows, and the earth is warm no matter where you are. Geothermal heat pumps, however, are more difficult and expensive to construct. This leaves solar and wind energy as the power sources most economically to capture and turn into electricity…
One of the problems with both wind and solar energy, as their opponents point out, is that they inconsistent. The sunsets at night, the sky can be cloudy for days, and the wind doesn’t always blow. Opponents of alternative energy would have us believe that as soon as the sun goes behind a cloud or the wind stills, our homes would be blacked out. However, this objection is based on a two misconceptions: first, that wind and solar power grids would operate like the current coal-fired power plants, and second, that both sun and wind sources drying up would leave us without any power at all. Let’s explore these two misconceptions in more detail.
Currently, coal-fired power plants generate electricity by burning coal to turn water into steam, which is then used to drive electrical turbines. The electricity generated by these turbines is fed directly into the power grid, where it is distributed. Under this arrangement, if one (or, worse, several) power plants shut off, nearby towns would indeed be without power. The huge blackout of the Northeast USA a few years ago is a prime example. This is not, however, how solar array and wind turbine electrical networks operate. Instead of the power grid being hooked up directly to the arrays and turbines, it is hooked up to massive battery banks that store electricity. The batteries, in turn, are constantly being recharged by solar arrays and wind turbines. Under this system, the battery banks feed a smooth, continual flow of electricity onto the power grid, even if the batteries themselves are being charged by fits and starts of electrical generation. Even if the wind is utterly still at nighttime, the battery banks could continue to feed power to the grid from their stored reserves of electricity for several hours until the sun rises again.
The second misconception involves the weather. A completely windless, cloudy day is rare. For the skies to be overcast and the air still for days on end is extremely rare. This is because storm clouds (that block sunlight from solar cells) are created by the collision of two air masses with different temperatures (higher pressure and lower pressure air cells). The collision of these two air cells also creates wind. In other words, if there are storm clouds blocking out the sun, they will most often be accompanied by strong winds. On the other hand, still, listless air occurs when one air cell dominates the area-in which case there will be little or no cloud cover, and the solar cells can drink up the sunlight. Furthermore, the sun setting at night results in a temperature change in the air, which creates-you guessed it-wind. This is why one often encounters stronger breezes around sunrise and sunset. Wind and solar energy complement each other nicely in this way – weather guarantees that whenever one type of natural power source is unavailable, the other type most likely is. For all these reasons, building more solar arrays and wind farms is the most efficient, economical way to capture natural power sources to fuel our nation as we head into the future.
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The railroad right-of-ways of N.America are from 100 to 300 feet wide, with other lands controlled by r.r.companies.
Solar arrays and wind generators could be installed in these areas…especially in desert and mountain regions, giving great assistance to the diesel engines powering their generators. The d.c. current could be stored or sent directly into the rails.
Also, any wheel that needs a brake should have a motor/generator. Just think of the long grades in mountain zones where, instead of energy being waisted on brake shoes, the m.g.s could be an aid in both directions.