James,
Your comments about the relative efficiency of compressing air with a windmill are spot on. Most of the energy would be lost. In the real world, air compressors are only about 10 to 15% efficient at best. This is because air heats when it’s compressed. In fact, since more energy is converted to heat than to mechanical energy, a compressor is actually better at heating and cooling a house as a heat pump than it is at compressing air. So unless you could figure out how to drive the Brumby well pump and utilize all the waste heat at the same time, a wind-driven compressor would not be the way to go. – Kenneth L.
Hi Jim,
Here is a link to Airlift wind pumps. [1] I have not used one of these but I have seen a lot of them in Arizona. It seems like a good idea. Regards, – Paul
Jim:
I found the following over at Amish News [2]: “Almost any electrical appliance can be adapted to work off of alternate power, such as compressed air. Some Amish women have been using compressed air to power blenders in the kitchen for years. In one house, compressed air powers a water pump, sewing and washing machines, and drills and saws in the shop. Some Amish businesses have as their specialty adapting such appliances so they can be powered by compressed air.”
From: the Unity College web site [3]: “This particular plant will make small-to-medium turbines for farm-scale installation, each turbine connected by an air hose to a large compressor tank. By both saving lots of air in storage tanks, and by scheduling manufacturing and other shop work for breezy days, the Amish can have compressed air without doing what they normally do, which is run a small gas engine to run the compressor. Gas has been expensive lately, and not all Amish church meetings allow the use of gas engines, so there’s reason to think that wind compressors will be welcome additions to the Amish toolkit.”
From OtherPower.com [4]: “There are many tools that can be run on compressed air. Many of the Amish use compressed air for kitchen appliances, fans, shop tools etc. A no-longer-certified propane tank makes a great air tank with large capacity.
Why not make a windmill that powers an air compressor? By storing compressed air I could reduce the size of the battery bank I need. Air tanks have a far longer service life than batteries and cost much less to purchase. Used tanks can be acquired for next to nothing.”s
I suppose that to obtain the higher pressures a reduction system would need to be used to obtain enough torque to drive the compressor. But what if a sail type windmill similar to the Dutch pump mills was used. I imagine those huge sails generate incredible torque. Here is a small mill that only generates up to 30 PSI intended for aeration of a pond [5].
And here is an air lift pump for pumping from a well [6]. (But there is no data on the pounds per square inch generated).
Regards, – Len S.
Sir,
Regarding Mike B. in Florida’s question on compressed air and wind turbines, I recommend that he research the combination of a Trompe [7] and a Savonius [8] wind mill. A trompe produces compressed air from falling water. A wind mill may be used to lift surface-stored water (pond or tank) to a suitable height to produce the falling water. I suppose any wind mill design would suffice, but I recommend researching the Savonius as it is supposed to perform well in areas with low wind speed such as Florida (ignoring the occasional tropical storm and hurricane). I do not know how much water must be lifted to what height to produce the quality of compressed required, but it may be worth looking into. Both devices are relatively simple (a trompe has no moving parts) and very reliable. – d’Heat