think of it this way when you toss a ball in the air it actually comes down a little slower that it was going when it left your hand because of air resistance but even under ideal conditions would come down at the same speed
your system producing energy would be akin to a ball so bouncy that it went higher with each bounce
I have been thinking along the same lines, but have had the same limitations as Brice has suggested. If it is being pumped from your well by electricity, then you can't produce enough electricity to pay for pumping.
However, if you are using county water, their water pressure puts it in your tank.
I also thought of using several small hydro units on the main county water line to my house, every time I run water then these units would be using county water pressure to produce small amount of electricity.
You could also put hydro units on your downspouts, no pumping needed.
The question I have is how long would it take to pay back on investment.
Power would only be generated when the water was running or being used. In a normal home water doesn't actually run through any pipes very much, with the exception of irrigation. Also when energy is changed from one type to another, there are inefficiencies. Water to electric = loss. Electric to chemical (battery) storage = loss. Chemical to electrical = another loss. The idea may be forward thinking but I believe it will not result in any gain, most likely a loss when all the component costs are considered.
no free lunch
I replied to a similar post of yours on another of the forums about feasibility of the general idea of water towers for hydro. I see now that I missed that you are "on the (water) grid" - e.g. planning to use the municipal pressure to put the water in the tank... and hence would have an essentially unlimited supply of water.
The slight ethical question another poster raised about "what if everyone did it?" is mooted by a reply that raises a bigger question. The reason you are not overusing your share of some ideal "community water pressure" supply is that they (presumably) charge you for municipal water. And I assume that charge is paying for their costs to pump it and pressurize it (in our town that is to another much larger village-owned tower. The real issue then becomes how much you would pay for large amounts of water.
But I see that you are probably not proposing using tens of thousands of gallons of municipal water per day to drive a hydro system !
Which means (please clarify if not) that you are planning to basically cycle your daily use through such a system.
With this we can use an analysis similar to what I posted on the other forum to calculate energy available based on volume of water and amount of "head" (drop).
Average 4-person household use of indoor water is 400 gallons per day. At 8 pounds per gallon that's 3200 pounds of water. Drop that 14 feet and you have 44,800 foot-pounds of work.
40 foot-pounds of work in a second is 50 watts of energy for one second. 1 foot-pound is 1.25 watts. But you wouldn't use all that water in one second.
If you ran all 400 gallons of your daily usage through a 100% efficient generator over the course of ONE HOUR (3600 seconds) that would give you about 12 foot-pounds each second or 15 watts continuously.
Not sure its a keeper ?!
same caveat as before !! I'm no expert - just someone who has wandered these paths numerically for a while.
Thanks for the input ! I pay for my water that I pump from my well. I pay for the electricity to pump it . however everyone that buys any water from anyone owns that water that they pay for ,period. This should answer the ethical question.If I could extract some power it would be a plus ( win win for me ) but I am told it is not feasable, so it won't work. I quit .
greggd, you need to look into the bedini motor. I have seen a few working in north idaho. i cant explain it. but its right up your ally.
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