Wind and Hydroelectric Power

So in my last post, I made reference to both wind power and hydroelectricity, and I briefly explained each, but I suppose it would be a fairly good idea to cover both of these in detail in their own post, as wind and water are both extremely copious sources of energy, as they are available literally wherever wind or water blows or flows, respectively. So without further ado, I suppose I'll hop right into two of the planet's most renewable sources of energy.

This post is brought to you by Mägo de Oz and their song "Molinos de Viento," also known as windmills:


iEspañoles son locos!

Wind power has been utilized by humans for centuries. Wind has been used to perform tasks like grinding up corn, to drawing up water, to sailing a boat, to even powering a house! Now, if you want to get really technically, windmills are used to provide mechanical energy, like the first three tasks, while wind turbines (also called wind generators, or if you're really cool: aerogenerators) are used to provide electrical energy, as in the last task; however, I am human, and thus I shall probably end up using them interchangeably throughout the course of this blog, so just for the sake of clarity, I mean wind turbines. Anyway, wind turbines are extremely simple. Essentially, the wind blows over the rotor blades, which causes them to rotate, which provides rotary power for a generator, creating electricity. Now, there are two main methods to doing this: the infinitely-more-common Horizontal Axis Wind Turbine (Left), and the slightly-more-obscure-but-at-the-same-time-kind-of-fun-to-look-at Vertical Axis Wind Turbine (Right). When a person thinks of wind power, generally they think of a HAWT, however LAWTs are gradually becoming more prevalent, due to some distinct advantages. Firstly, HAWTs must be built fairly tall so as to gain access to fast enough winds to cause a rotation, but LAWTs are able to rotate with slower wind speeds. Furthermore, HAWTs are extremely difficult to transport, as the blades must come in one piece, and most of them are half as long as a football field; however, LAWTs generally don't have to come in massive pieces, and usually aren't nearly as tall. Lastly, the generator and most of the moving parts in a HAWT are hundreds of feet in the air, while the generator in a LAWT is close to the ground, making it easier to repair, should it break down (a good rule of thumb to remember is that in every machine ever designed ever, the more moving parts it has, the more likely it is to break). However, despite all these advantages, Horizontal Axis Wind Turbines are far more popular, simply because they are more efficient, and generally perceived to be sturdier. However, HAWTs are catching on. One up-and-coming method of using wind turbines is to install a relatively small HAWT on top of a building! This serves as a double-whammy, as the building itself redirects wind to the roof, oftentimes doubling the wind speed, and also the very electricity produced by the turbine could simply go straight into the building beneath it. Anyway, I suppose I'll just sum up wind power with this: from what I've researched, wind power is completely and utterly renewable, but it just isn't efficient enough to replace oil. Right now, wind accounts for about .3% of the planets energy, while nonrenewable sources account for over 90% In theory, if we could cover the planet in 300 times as many wind turbines as there are now, it could work, but in practice, I just don't see it happening. However, wind power, in conjunction with other renewable resources, certainly could do the job.



Hydroelectricity is currently the most widely used source of renewable energy. In 2006, hydroelectric power plants supplied almost 3000 TeraWatt-hours of energy, accounting for 20% of the entire planet's electricity, and 80% of the electricity from renewable resources. Clearly, as the planet has plenty of water to spare, hydroelectricity has the potential to power the planet.

So I suppose I'll rap to ya about how this hydroelectricity works. There are several methods of deriving energy from water, but the most common method is through damming water, such as in a river, and releasing it gradually in order to spin massive turbines and generators. Essentially, it's very similar to wind power, except with moving water as opposed to moving air. However, that's just how the typical, orthodox, conventional, boring hydroelectric plant works. There are entirely different methods of utilizing moving water that, while less common, are gradually becoming more prevalent in the world's energy supply. Pumped Storage Hydroelectricity does not involve a dam. Rather, it just has two massive reservoirs, one at a high elevation, and another at a low elevation. When there is a high peak demand, literally when there is the highest demand for electricity, water will flow from the high tank down to the low one, spinning a turbine along the way. Then, during times of low peak demand, any excess energy can be used to pump water from the low reservoir back up to the high one. This method, however, ultimately results in the system using more electricity than it produces. However, it is capable of making money by creating energy during high demand and using it during low demand, even though it technically consumes more than it produces. This allows it to have the largest capacity for grid energy storage. Another mildly intriguing source of hydroelectric power is known as a Tidal Plant. This method uses the changing tide from the moon's gravitational pull to create energy and electricity. Clearly, there are plenty of schools of thought as to how water can be used to meet the energy needs of the planet.

So I suppose I'll do some pros and cons. A nice thing about the big ol' dam idea is that after building the dam...that's about it, other than a bit of maintenance here and there. As long as water flows in the river, it will continue to crank out electricity. However, a negative aspect of building massive dams is the huge impact it can have on ecosystems...downstream. Plants and animals often rely on rivers for food, drinking water, and shelter. However, dropping a big dam in the middle of a river drastically decreases the amount of water available downstream, and thus these ecosystems suffer. Pumped Storage Hydroelectricity does not have this adverse effect on the environment; however, there is the negative aspect of the fact that it isn't nearly as efficient, as at some point, that water has to be pumped back up. Tidal plants solve both problems; however, the areas in which there is enough of a tidal change and a fast enough flow of water to spin a turbine are extremely limited. So really while each one has its benefits...there's not really one specific method that's better than the others. Unless if we combined them all into a super hydroelectric power plant o.O but that's just preposterous.

Anyway, I'll wrap this up now if you don't mind. Hydroelectric power has the capacity to replace oil, if we can expand the industry. Furthermore, it's only a matter of time before the technology we have now is improved to the point that the aforementioned negative aspects become fairly negligible. Again, the best-case scenario would be to use hydroelectric power in combination with other sources of completely renewable energy.

This post took almost 2 weeks to complete.