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Jet Engine

Focusing a flow of air from a low to high pressure area is the principle that a jet engine works on - and the ideas that you are talking about sound theorettically good - but there is a problem - when you focus a fluid such as air into a turbine-like device an impotant principal comes into effect - this principal states that when the pressure of a fluid flow is directly proportional to the speed.. So by incresing the pressure (turbine or funnel) you in effect increase the speed of the airflow. Therefore, the turbine blades must spin at a much higher speed to harness this energy. A jet engine does this, but unfortunatly, most spin at incredibly high speeds - tens of thousands of RPM's. It is just not feasable for a layman to build such a thing. Special bearings and blades are needed, not to mention the need to balance the rotating part so that it doesn't vibrate. Unless one is a mechanical engineer and has access to machine tools, I really dont think it is worthwile to try to build a wind turbine.

There are commercially available ones, but the cost is probably prohibitive - being that even the cheapest commercially available windmills are in the 1000$ range. A simple set of propeller blades can provide more than enough energy (10kW for example) to a simple generator to feed a single house or dome. The real problem is speed - you need to regulate the speed of a wind generator. (When a 200 mph hurricane comes the thing will tear itself apart!). I am thinking more along the lines of using an old airplane propeller that has adjustable blade pitch - its called feathering - when the wind speed increases you can tilt the blades to adjust the speed. This would be a good idea for a layman-built wind generator. An even smarter idea would be to try to spring for a $5000 generator built by professionals - they give out like 5-10kW, which is enough for a well pump and some grow lights. That is what I am figuring on. All I am really saying is that wind-generation is not as simple as it seems.

Offered by Robert.