Compressed Air From Wind Turbines

Oh boy - someone is going to take you to task on the "save 8 times the electrical enegy the 'windmill' can generate." Start thinking of your proof of this statement.

I was referring to the 'textbook' information that most of the energy used to compress air is wasted as heat. Only a small fraction of the electric energy is actually used by the compressed air. If a wind turbine can compress air directly from mechanical energy the process is claimed to be much more efficient, although naturally heat will also be generated.

Does it matter is the driving force is electricity or wind power, then? What happens in the case of a simple bicycle tyre pump? If one were to drive the pump with wind, would one expect the pump to run hot or not? If one were to substitute an electrical drive, would one expect the pump to run hot or not?

http://en.wikipedia.org/wiki/Ideal_gas_equation

It is possible to compress air through a wind mill. The wind mill has to be connected to a compresser through a step up gear box.

ya, surely it is possible.as we have to store the energy from the wind in the form of compressed air,a gear box can be used for the uniform supply of energy..

for this specially designed sensors can also be used..

we are worried about the areas which have very low wind density or we can say very low wind velocity through out the year.for that regions we will need to couple the gears with large gear ratios.for example if we couple a gear with 100 teeths connected to the main shaft to a gear with 20 teeths,we can manage to get 5 times the speed of the rotor blade.the latter teeth can now be coupled in a gear box to obtain the desired output.

in this way we can get a higher rpm,which can be futher used effectively.

wind turbine air compressors have many applications so a lot more research is needed to increase the efficiency..

As you may know wind is NOT constant so that a wind generator can be effective or not. The compressed air is used as an energy accumulator to be used when the wind is low and electricity is still needed. So the principle is to use all available energy over instant request to compress air and recover even a small part of it when demand is present but not wind. It is still the most economical way for saving energy surplus.

Actually, using a hydraulic storage system would be a bit more efficient than compressed air...

It depends how you can do it. If you consider hydraulics under pressure then the accumulated energy is a lot less due to the high bulk modulus of hydraulics.

If you consider pumping water in to a tank and use it when needed to actuate a turbine you are right, but have you thought about what it will cost to have same energy reserve this way? how much will cost as investment the building of a reservoir in flat land? If you make a simple computation you will see the differences.

It is a problem of global economics not only of recovering efficiency.

The viability of an energy transport media depends on the regional infrastructure available.

Many cities and towns have some sort of water tower or reservoirs to store their drinking water. Some don't have it but would like to have one. In this case, using the windmill to pump the water is much more advantageous than producing electricity as all most of the problems associated with the windmill fluctuations are solved. There is some side effect as the electricity normally used for this task is off peak hours but they can find another use for it.

Storing compressed air is not efficient because of the thermal cycle involved in both direction but if you have an application that already use compressed air then you have a winner. There are many "gas" plant that use cryogenic to separate the various gas from the atmosphere. If you had your windmills near such a plant, it could supply them with pre-compressed air to save on their compressor electricity bill. The compressors would run at full capacity when the wind is down. This way you don't need to store anything. You use as you produce!

Compressed air is used in many water treatment plants (potable and waste) to aerate basins, to extract the oxygen with VSA/PSA, and as a maintenance tool to blow off pipes...

I am certain that there are many other industries that consume a lot of compressed air that could use the production form the windmill within a reasonable distance. You don't want a thousand Km pipe line either.

Steam could also be produced but it is much more challenging than compressed air.

Warm air could also be produced but its "energy density" is very low and would need too much transport infrastructure for most applications. The only exception would be if the mill is on your roof or just beside.

Compressing freon could be done and supply AC or heating to a house or neighborhood. Leaks would be a problem though.

As Cwarner mentionned above, hydraulic could be used. If there is a plant that uses it in large amount, so be it. Don't try to store it. Turn off the pumps on windy days...

Compressed air is cleaner. A leak looses energy but does not create an environment nightmare.

Windmill could also be used at pipeline pumping stations. It would work whether the line is filled with gas/oil or water.

The viability of an energy source usually depends on its use. We have to stop thinking conversion. We have to look at what is being used in what form. Even if electricity is the "standard" energy, it is not always the best choice. Not all the wind farms will be located in convenient areas but some will. Lets make the best of it. It might make all the difference in the economics of the technology.

There are wind driven pond aerators made now that use a diaphram or rubber boot compressor
Some utility companies are using old salt mines to store compressed air
and a friend tells me that some oil companies use an airplane like device
mounted on the derrick and when it's wing change pitch up and down it
moves up and down and creates massive hydraulic pressures in a cylinder
to change wind power to hydraulic power
but I haven't been able to find that application on the net
I would like to see a video about it

You could use a Trompe to compress air....

http://en.wikipedia.org/wiki/Trompe

Hi,

I saw -some time back, where a farmer was using an old lawnmower engine, connected directly to a blade. By removing the spark plug, and putting in a checkvalve he was able to use the wind to compress air and then use the air to run an air motor down inside a well to pump water to a watering trough for cattle. It was simple and when the wind blew quite an ample supply of water was pumped into a large -open topped tank for the cattle to use. I think it was in Australia...

Sorry I can't be of more help, but I've seen air motors for sale in pump catalogs...Hope this helps

Babygrapebooks.com

Long, long before the current buzz over windmills, throughout the midwest US farmers were using windmills to pump water into stock tanks directly, without converting the energy to electricity or air. It works. I have also installed solar powered water pumps in remote locations for similar purposes. It works. However, as pointed out above, one must evaluate the economics of such situations to determine what the most cost-effective solution is, depending on local conditions...

As already mentioned, because wind power is not constant, then ideally some means of storage is required. The compressed air technology is supposed to provide a means of storage. The link below gives you the idea.

http://www.reuk.co.uk/Storing-Wind-Power-with-Compressed-Air.htm

For specific applications what you suggeszt could hold a significant advantage compared to a wind turbine generating electricity.

Where there is an end use need for compressed air, such as a plant that has many pneumatic handtools or demanding pneumatic equipment, in a locale conducive to efficient utilization of wind power, there may be a significant benefit to producing the compressed air directly.

Cutting out the electrical portion of the system and directly compressing the air,a more simple, more efficient system could likely be build, (compared to a system that first converted to electricity then used that electricity to compress air.)


While that comparison itself is not often directly made (I don't think there is a high demand for industry looking for wind power soley to power pneumatic equipment), It does argue for evaluating wind powered pneumatic or hydrolic systems with electrical backup as a possible option in many real world projects.

Benbenben

Read post #9.

There is a company that makes wind powered air compressors. http://windcompressor.com Their largest model will put out up to 30CFM at 175 PSI. It is a 10HP with 17.4 ' rotor diameter. Most people using them store the air in used propane tanks. I bought one last year and it has worked out great. Regards, Steve O