“Wind Power” is the extraction of energy from the wind. Common techniques use a tower with a set of propeller blades that will spin when wind blows against them. Wind power is a renewable form of energy because wind is caused by the uneven heating of the earth by the sun. The lifespan of the sun is sufficiently large, measured in billions of years, that we are not worried about its demise, yet.
The earth’s wind has an enormous amount of energy in it. If even a tiny fraction of it were harnessed, it would provide for the entire world’s energy consumption. The reason this has not happened yet is because there have been cheaper alternatives. Except in a few specific circumstances, no renewable form of energy has been able to compete evenly with fossil fuels in terms of cost-per-watt until relatively recently.
Changing the wind into a form of energy that is useful to us is the most challenging step. With the world’s changing energy market as of 2008, wind has become closely competitive with fossil fuels in many areas. With government incentives in place, wind power has become the best choice for new development in several major nations including Spain, France and Germany. Cost-per-watt analysis now tends to favor wind power in many areas because of the rising price of fossil fuels due to increased consumption and extraction difficulty.
Implementations
Global Implementation
We are seeing an explosion in the growth of the wind power industry. The amount of energy produced by installed wind power stations around the world is increasing at approximately 20% per year. This incredible demand for wind power has caused the price of wind turbines to increase considerably.
Wind turbines have a long lifetime. Most are estimated at over twenty years. It is likely that with good maintenance, many will last much longer than that. Compared to other forms of energy, wind turbines typically have a low cost per kilowatt. The disadvantage of wind turbines is that the majority of the cost is incurred before and during construction, so a large investment has to be secured long before any power is generated. This can be contrasted with coal, where much of the cost of coal power is the operation of the plant and the acquisition of fuel.
On the scale of very large nations for instance, wind power tends to average out to approximately the same output as long as the turbines are spread out geographically. Thus if the wind slows in one area, it should not cause the whole nation’s production to decrease too much in this situation.
On a global scale, it might be possible to provide baseline power with solely wind. The costs of maintaining a power grid capable of handling the intermittent nature of wind on that scale would be very high. In general this is regarded as infeasible, and other energy sources are generally used in conjunction with wind power to create a power grid. For instance, hydroelectric power can be ramped up to meet demand in the case where the wind dies down.
Small Scale Implementation
Non Grid-Connected Wind Power
An advantage of wind power is that home-made turbines are possible, and investors often see good return on their investment. A homemade project does not require as stringent control of power quality as required by a utility, so some cost is removed. Keeping in mind the intermittent nature of wind, the setup cost of a wind generator is very reasonable. Some applications such as livestock pumps are well served by wind or solar power because they are often far from the grid physically. Building wind or solar installations is quite often a practical choice when such renewable power sources will cost less than a grid connection to where the power is needed.
If you wish to have a reserve of power for use during calm times a battery system is required. An array of batteries, whose size depends on how much reserve you feel is necessary, will need to be purchased. Simple electronics exist to make building and managing a battery storage system easy; but no matter how you cut it, a power reserve is expensive. In very remote places this might be your only choice, as grid connection is not available or prohibitively expensive. Renewable power generation such as wind would likely have a lifetime cost well below that of a fossil-fuel generator.
Grid Connected
A grid connected system requires that you meet the standards of your utility’s power quality. Some utilities require that you rent or buy power transforming equipment from them at whatever cost they choose. Some utilities will write you a cheque when you generate more power for the grid than you use, some others will reduce your power bill by the amount you produce, but will not pay you for power you generate beyond that which you use. The choices your utility makes is highly dependent on government pressure to support small scale power initiatives.
The advantage of being grid connected is that your power availability is more reliable. You still have grid power when the wind is low and can produce power when the wind is blowing. This is the optimal choice if your government is supportive of small scale power generation and you live near enough civilization to be cheaply grid connected.
Implementation Issues
In general, the wind speed increases the further from the ground it is measured. At altitudes of about 10km, it is possible to find consistent 160km/h (100mph) winds. It is thus advantageous to build on top of hills, and with tall towers to reach faster wind speeds. This is because a wind turbine’s power output potential is based on how fast the wind is blowing through its blades.
Wind turbine locations are chosen based on how windy the area tends to be as well as closeness to where power is required. One possible problem is that each turbine design has a maximum wind speed associated with it. Areas that get extremely high speed winds on occasion may be problematic since they are likely to occasionally force a shutdown of the turbine(s). What works best for wind power production is relatively steady and fast wind.
The specifics of how wind turbine installations are managed, and how they connect to the power grid, vary depending on location. In general, the wind turbine installation will have the electronics required to transform the power generated into a form that is consistent with the power on the grid.
Upkeep
In cold climates, a warming system is required to keep certain parts from freezing when their own heat of operation is not enough to do so. Periodic inspections of the equipment has to be made to ensure the integrity, similar to the maintenance of a hydroelectric plant. Upon inspection parts may need to be replaced and lubricants may need periodic attention, depending on the turbine design.
Production
Wind turbine parts are made of modern materials which are difficult and expensive to make. A wind turbine factory can not be built overnight because of the high grade and complexity of the parts. Because of this, industry has a hard time keeping up with the explosive demand for wind turbine parts, thus the cost of parts has recently risen above what had been the expected cost. Long-term however, the wind boom is going to drive down the price of turbines due to increased availability and innovation.
Advantages
Wind power requires minimal maintenance, no fuel costs, and no elaborate cleanup. It causes no known health damage in humans, has a minimal carbon footprint, and requires minimal land area. While wind farms are spread out over large areas, the land around them can still be used for other purposes, since their physical footprint is minimal. Another advantage of wind power is that home-made turbines are possible. This allows home or business owners to reduce or eliminate their power bill with their own generation. Investors in small scale wind often see good return on their investment.
Disadvantages
A downside of wind turbines is that they will create flickering shadows that can be disturbing to people who live nearby. It is the norm to install all large scale wind installations far from heavily inhabited areas. It has also been noted that urban installations can be a source of noise, and can also pose a danger to things nearby in the case of a catastrophic failure. Zoning laws often restrict the construction of urban wind power generation. Home turbines in general are not as efficient as large-scale projects, but they can still be excellent investments in windy areas where they are legal.
Wind cannot provide consistent baseline power on the small scale. The wind is not steady and constant. So power production would rise and fall depending on the speed of the wind. If a city for instance powered itself entirely with wind turbines that were built nearby, it would be dependent on the wind speed to remain high enough to power the city. If the wind slowed down too much, the city would not have enough power coming in to meet demand.
In extremely high-speed winds, wind generators must often turn off. This is a considerable disadvantage because there is a great amount of energy that is not being utilized, and because it means a complete stop to the wind farm’s energy production for a while.
Adaptations and Variants
Floating Wind Turbines
Wind turbines have been build on the open ocean. This negates the usage of valuable land, and also negates the problems of urban development. The disadvantage is that they use space on the ocean which has to be near shore. Ocean near shore is usually in high demand. Actual space use is quite minimal, but some groups of people have protested against the construction of offshore wind farms. See “Cape Wind” on wikipedia for an example.
Flying Wind Turbines
Since the wind speed up higher is so much greater, often steadily in excess of 160km/h, it is advantageous to get as high as possible. Kite or balloon based wind generators can be placed near the jet stream and can in theory produce more than enough power to warrant their complex construction. Research into the possibilities for flying wind turbines continues today.
Vertical Shaft
Vertical shaft wind turbines use a spinning shaft that is perpendicular with the ground rather than parallel with it. The vast majority of turbines built in the world so far have been horizontal shaft.
Building Focusing
Some thought has been given to using buildings to funnel or focus the wind into smaller turbines which could be used in urban settings.
Fluttering Wind Power
Extremely small scale wind power devices have been designed that use the fluttering effect due to the viscosity of air. These devices do not spin, they ‘flutter’. Practical research is still being done into these devices.
Case Studies
Saskatchewan has a max production of about 170MW from wind power, due to our three installations in the south west corner of the province. Sunbridge, Centennial and Cypress. Load factors for these installations is above 40%. This is considered extremely high since wind installations around the world rarely see load factors that high.
Germany, Spain and France have extensive installations and large-scale investment due primarily to major government support.
Denmark produces about 20% of its energy using wind, and is still adding more. This is very impressive considering the small geographic size of Denmark. The intermittent nature of the power is compensated for by generators that can be turned on quickly, both in Denmark and in nearby Germany. Denmark generally exports power when the wind is blowing hard and imports when it is weak.
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“The disadvantage of wind turbines is that the majority of the cost is incurred before and during construction, so a large investment has to be secured long before any power is generated. The up-front cost of a wind farm is still far below that of large centralized facilities such as nuclear or coal power plants.”
Isn’t the large investment necessary for most large scale power projects? Did I miss something?
“On the large scale, of very large nations for instance, wind power tends to average out to approximately the same output as long as the turbines are spread out geographically. Thus if the wind slows in one area, it does not cause the whole production to decrease too much.”
Does this take transmission costs into account? If one area of the country has a lot of people, but not many turbines, then there is a transmission loss to bring power to that area, isn’t there?
Seems to me that transmission issues are what really prevent renewables from taking over globally, at least where technical problems are concerned. Never mind political and economic problems.
In general this is regarded as infeasible, and other energy sources are generally used in conjunction with wind power to create a power grid. (See germany’s 1% project, where they power 1% of their country on completely renewable energy).
(Germany should be capitalized, and there should be a link to this project, from wikipedia it seems that Germany wants to have 1/8th of its energy coming from renewables by 2010. http://en.wikipedia.org/wiki/German_Renewable_Energy_Sources_Act)
re: Small Scale Implementation (non-grid) – I wonder if the Canadian government provides any incentives for people to do just this in the Far North. If not, they probably should, I remember reading back in the day about the high costs of diesel really affecting communities up there. Wouldn’t it be great if Canadian industries really beefed up the small-scale wind turbine for harsh climates like the Far North? Seems like we’re ideally suited to own that industry. (same with solar, I’d imagine)
re: Small Scale Implementation (grid) – Maybe there should be a small analysis of the following question: At what distance from a power source do transmission losses make it better for the whole grid for a user to install their own wind turbine? It would be in the best interest of the utility to provide incentives for people at that distance and further to use small-scale renewables like solar and wind.
First to address your first question, about the investment for large scale power projects. A wind project requires land rent/taxes and maintenance costs over its lifetime, while the majority of power plants (coal, natural gas, even nuclear) also incur fuel costs over their lifetime. These power plants do not contain all of the fuel that they will burn over their lifetime on site at construction. This substantial cost is the key difference, those power plant types can incur those costs gradually, spreading out the debt load over time.
Second question, a more distributed population works best with distributed power. When discussing mega-projects the transmission costs are often included because they are relatively small when compared to the other costs. The distribution pattern would have to be adjusted accordingly with particularly dense areas, and those adjustments would either increase transmission costs or cause intermittency to be more of a problem by increasing the wind farm density near those cities.
Regarding non-grid small scale power, I imagine some of those industries are smart enough to do that themselves, without government intervention. After all, if you think it will save you money, why wouldn’t they do it themselves?
Your last question, this distance would be highly dependent on the state and other uses for the infrastructure in question. This problem can become very complex very fast as you analyze a line with multiple users at different locations, etc.
Also, I wouldn’t consider this a ‘grid’ problem, because if you truely want to remove that power line to save money, the person has to have a substantial enough power system to go completely grid-less.