Why Not....
- From: "Amused" <jamescopeland@xxxxxxxxxxxxxx>
- Date: Wed, 6 Aug 2008 11:59:23 -0500
My S-I-L asked, "Why wouldn't we just build a wind generator and get our electricity for nothing."
And it got me to wondering...why not?
First off. Wind generators are B-I-G. The newest models are 250' feet tall to the hub. Each blade is 130 feet long. Those towers are subject to immense stresses. Therefore the bases for the towers aren't just a couple of legs stuck in the ground. They are highly engineered and must be anchored to some type of bedrock, in some way, (or some damn deep pillars).
The blades start spinning with wind speeds somewhere around 9 miles per hour. Now, 9 mph is not all that fast, BUT calculations show that the average wind speed needs to be about 15 mph over a year, to get the 9 mph most of the time. The eastern half of Kansas (which exceptions) doesn't measure up. However, the western half does achieve the 15 mph minimum.
It has been calculated that a wind farm covering 100 square miles could actually produce all the power necessary for Kansas plus some additional power for the national grid...MOST of the time.
Wind turbulence is the next consideration. Turbulence is a major consideration. Again. Remember that in creditable amounts of torque and stress are placed on the blades. Turbulence can actually cause one blade to be pressing in one direction while a blade on the opposite side is pressing in the opposite direction. Theoretically, it's possible to have a wind generator standing tall in a 15 mph wind, and the blades are not turning, at all.
Wind studies for potential sites take at least a year, and normally two years, and they're not only measuring wind speed, they're measuring wind direction AND the comparing the wind direction across the entire grid of the potential farm.
High speed, straight line winds are much less of a worry, than medium speed swirling winds. It's theoretically possible for swirling winds, plus the immense torque generated to twist a wind tower right off it's base. (Never happened, AFAIK).
Most wind plants shut off completely when wind speeds exceed 45 mph. Apparently the vibration and the harmonics of a 260' propeller spinning at ultra high speeds scare the bejesus out of the most ardent engineers.
(If I was going to bet on a 250' tower standing up to a tornado, I'd bet on the tornado)
The highest draw on electricity is always in the summer. In too many areas, even with 15 mph average speeds, the summertime wind speed is too low to even turn the blades.
-> Therefore, full capacity backup generation capability is required. There are actually very, very few places in America where a wind farm could actually meet 100% requirements year-round.
-> Just because a wind generator cannot meet 100% of requirements, doesn't mean it's not economical or desirable, BUT it's a big cost factor.
A single wind tower is expensive. It's expensive to buy, it's expensive to install, and there is an ongoing maintenance requirement.
Remember that 10 mile by 10 mile wind farm? It's been estimated that it would create 3,000 new jobs just to keep it in operation. Of course, THAT'S not necessarily a bad thing, but it is a cost factor.
It takes many hours and sometimes days to fire up big generating plants. Therefore, most of the time, a standard plant is normally up and running EVEN if there is very little draw on actual power generated. (Happens almost every night). What wind generators can do is to reduce the use of other fuels in the back up generation sector in the "off months". Fixed generators can be shut down, and fossil fuel requirements reduced. Therefore, the total fuel expenditure for a year is reduced, (sometimes significantly) but it's almost never eliminated.
-> Basically, most of the time, a wind farm can significantly reduce the need for additional future power generation facilities to some degree, AS long as the existing facilities can "gear up" to handle peak loads. This is where the national grid can be of immense help in leveling out the peaks and valleys.
Therefore, bottom line...wind generation is NOT an alternative method, it's a supplemental method of power generation.
Now, consider a separate observation. Just when wind generation is dropping towards zero (in the summer), solar power generation would be reaching it's peak efficiency. Again, this would allow for smaller backup plants.
In a perfect world, a combination of wind-solar-nuclear, thoroughly integrated over a wide area would be the most optimal arrangement.
Connection to high capacity, cross-country transmission lines is a major consideration. In even, low-density population areas, constructing such lines can reach a million dollars a mile.
There is initially, a high impact on wildlife populations, especially birds. BUT! 100 square miles is not a very big area, and quite quickly, the birds learn to go around...(or they die).
There are other "hidden" costs, to be considered. As it happens, the best places for wind farms tend to be in very remote locations. This is good and bad. For instance, in building the 100 square mile farm, you'd have to build a frigging town just to house and support the construction crews. (Estimated temporary jobs....24,000) not to mention temporary cement plants and highways good enough to handle very heavy truck traffic.
.
- Follow-Ups:
- Re: Why Not....
- From: Ron Ford
- Re: Why Not....
- From: Ouroboros_Rex
- Re: Why Not....
- Prev by Date: Re: Okay...It's a bit TIG....
- Next by Date: Re: [NP] [SW] - Go even greener with your PC
- Previous by thread: The Earth Is Losing to the Oil
- Next by thread: Re: Why Not....
- Index(es):
Relevant Pages
|
Loading
