|
|
Posted by D Sherman [72.47.9.228] on Tuesday, August 10, 2010 at 00:47:52 :
In Reply to: OT Anybody know posted by clueless [201.202.22.114] on Sunday, August 08, 2010 at 22:33:17 :
But if you're serious about this it's worth learning a tiny bit of 19th century engineering. Many good books on the subject and the old ones tend to be the most practical and easy to understand. The first thing you need to know is that power is proportional to head (elevation difference between the inlet and your turbine) times flow (gallons per minute). The next thing is that the bigger the pipe the better, and any good book will give you tables you can used to calculate how much loss of head you'll get at a given flow rate for various types and sizes of pipe. The next thing to read up on is types of turbines. For high-head, low flow situations, a pelton wheel is best. They can achieve 90% efficiency but need to be run at precisely the right speed (velocity of the wheel at the rim equals half the velocity of water coming out of the nozzle). Low head, high flow situations also work fine, but you use different times of turbines (Kaplan, Francis, or cross-flow). Again, the books explain what kind is best in which situation.
You can try to mickey-mouse it using folklore, rules of thumb, etc, and you can probably get water to turn a wheel, but it won't be very efficient. A good hydroelectric site is a rare and valuable resource. It's worth doing a little bit of engineering to make good use of it.
There's also the matter of environmental permits and water rights, depending on the government where you are.
Follow Ups: