Science Buddies: "Ask an Expert"

I'm doing a research project that is due in a few weeks. Basically, what I want to do is calculate the force that running water inside of an average home could produce. Then I want to determine if that force could be used to turn a small turbine and produce a usable amount of energy. Note: My calculations will be based on the amount of water the average household already uses. Can someone please give me an idea of what concepts I need to master and formulas I need to know in order to this? and/or tell me where I can find this info.

Hello scitist,

The force, momentum, energy, and other measures of water flow can be calculated from Newton's basic laws of motion. Of course, one is unlikely to figure these out on his own in a short period of time. What you need would be covered in an Introductory Physics text book at the advanced high-school level or college level.

Web searches for "force of running water" and things like that will also turn up useful information.

Keep in mind that if you extract energy from the water flow, the flow will have less energy and therefore fill the tub slower or spray shorter from the garden hose.

If you want to ask a more specific question, get back to us.

Good luck, WW

If you only want a quick guess at an upper bound, you might look at the problem from the opposite viewpoint. How many horsepower is required to drive a well pump capable of supplying the typical household, how many gallons per minute or cubic feet per minute does it provide, and how many gallons or cubic feet of water does the typical household use. 3/4 to 1 HP pumps are typical for most household wells depending on the well depth and the gallons per minute provided. Average water usage is available online for various communities from municipal water utility companies.

Given that tyical water usage occurs at many different flow rates, it would be extremely difficult to recover even a small percentage of the energy required to pump the water with any water driven generator. It took many years before it was econimical to deploy remote reading water meters. These devices measure the water and generate a very small amount of current that is able to power a very low power LCD remote display that allows a meter reader to not have to enter the building to read the meter (meters in cold climates have to be placed inside a heated structure or burried below the frost line to protect freezing).