power from water tower

140 foot tower creates more than 60 psi,… it a regulator that sets it at 60 psi.

as far as pressure loss, that’s dependent upon flow, statically, there really is no pressure reduction.

I stated"about 60PSI". To be more precise, it would be 60.693850269955284 PSI at 60 degrees F.

This is measured at the base of the tower.The elevation of the user will affect the actual pressure.Some areas require regulators if they are geographically significantly lower than the tower,and some areas require booster stations to raise the pressure,depending on distance and elevation.I am referring to pressure at the base of tower itself,which I thought would be obvious,I hope this clears it up.Any time you put a turbine in a flow,there will be a pressure drop downstream.

Cities use water at the rate of thousands of gallons per minute in some areas,so that flow is leaving the tower.

Water is constantly moving into and out of these towers,it is not static tank, with water just sitting there.I am talking about harnessing a some energy from the output side of the tower.

Even small communities have several towers with large flows.

I am obviously not seeking an over-unity device,merely a small useful return on the energy used to get the water to the tower height.

The water is going to flow anyway,why not use some of the energy?

Pressure regulators are pretty simple and compact devices consisting of a spring-backed diaphragm controlling a valve. You could replace a pressure regulator with a fluid motor driving a generator charging batteries with feedback from the output pressure to regulate the charging current.

It sounds like a workable idea, but I'm guessing that the energy scavenged this way would not pay for the added complexity, maintenance, and space requirements.

You showed a pretty basic pressure regulating valve. Now picture a cone valve on a 60" diameter water transmission main. Used an extension ladder inside the manhole just to get to the top of the valve! 15+ mile transmission line with 200' fall from the dam; had to decrease the pressure at the city end when flow was low, but had to add 2 or 3 300hp pumps to supply adequate pressure when the flow was high.

--JMM

I think some of the Smart water meters use the internal flow to generate sufficient power for the transmitters,albeit very low demands.

Exactly. If there were head to spare to drive a turbine, the tower wouldn't have been built so high in the first place.

Water at elevation is energy stored, if you remove that energy with a parasitic generator device, then that energy is subtracted from the system, causing the pressure to drop...

"Pumped storage hydropower (PSH) is a type of hydroelectric energy storage. It is a configuration of two water reservoirs at different elevations that can generate power as water moves down from one to the other (discharge), passing through a turbine. The system also requires power as it pumps water back into the upper reservoir (recharge). PSH acts similarly to a giant battery, because it can store power and then release it when needed. The Department of Energy's "Pumped Storage Hydropower" video explains how pumped storage works.

The first known use cases of PSH were found in Italy and Switzerland in the 1890s, and PSH was first used in the United States in 1930. Now, PSH facilities can be found all around the world! According to the 2021 edition of the Hydropower Market Report, PSH currently accounts for 93% of all utility-scale energy storage in the United States. America currently has 43 PSH plants and has the potential to add enough new PSH plants to more than double its current PSH capacity."...

https://www.energy.gov/eere/water/pumped-storage-hydropower

Probably better to just add some solar panels to the roof of your water tank....or put a small turbine up there, of course the cheapest way is going to be just run some wires from your existing grid connection....

Like this.

The first known use cases of PSH were found in Italy and Switzerland in the 1890s, and PSH was first used in the United States in 1930.

I'm afraid I have to dispute the dates. I'm slowly working on a history of the Louisville, OH, Fire Dept. Louisville, OH, started installation of a water system in 1894, completed in 1895. Besides wells, steam pumps, pipes, and hydrants, a central part of this system was a "standpipe" that was 100 feet tall. This was a cylinder about 16 feet in diameter; today it would be a tank on legs. They never heard of "pumped storage hydropower," but it amounts to the same thing.

This leads to a question: How big was a barrel of water circa 1890? That is, how many gallons were in a barrel back then? Their fire fighting cisterns, and most capacities, were given in barrels. But a barrel size has varied a lot over the years; how big was it circa 1890?

Thanks.

The answer to "How much did a barrel hold?" needs to have more information.

I worked for a while in the wine industry and barrels come in a multitude of sizes (volumes) and each has a name. There were "hogsheads" (230 -250L) and "puncheons" (500 - 700L) "Quarter casks" (125L) and "octaves" (50L). There are multiple other so called standard sizes.

Most places would default to the hogshead size, that in America morphed into a 200L "American standard"

Source based on images available from American Whisky Exchange.

What more do you want? You mention liters, so you are thinking "modern stuff" I suspect. I'm asking about water in the 1880s. Specifically for filling of firefighting cisterns and other uses shortly after Louisville, OH, was incorporated in 1872.

Perhaps you mean water flowing down from the overhead tank . It is good idea and some energy can definitely be generated.

Another way which I envisaged and my idea was published in Newspapers is using HYDROPHOR system whereby underground water is flown to required height under pressure, as and when required.

By doing so we can save energy used in pumping water all the way to overhead tank whereas it is again to be brought down to lower floors for use. By adopting this HYDROPHOR system one can reduce the electricity bill by approximately 50%. Of course the initial cost may be slightly high which can be recovered by the saving in electricity bills.

S.K.Patel

Mumbai, India

Water turbines can be used to as pressure reducers but usually in bigger applications than this and where the water pressure is unwanted, in this case the water is up there because you want the pressure.

Also, there will be changes in water demand over they day and therefore in flow rate. This will cause changes in turbine speed. You could use a voltage regulator as in a motor car alternator but I think we may be talking about motor car alternator sized output. Is the game worth the candle?

In Scotland we have a lot of water (I'm watching it fall as I type) and a lot of mountainous terrain. We have man made reservoirs for public water supply and for hydro-electric generation including pumped storage. As far as know we use the systems for one or the other and not both together. There must be some underlying reason for this. The water supply regulations forbid consumers from generating power from the public water supply but the supply companies are not so constrained, so I suspect they have a more fundamental reason for not doing so.

If you want to generate power from a 40m high structure, how about a vertical axis wind turbine. Safe to use in populated areas and keeps within the footprint of the tower.

..."Pumped-storage hydroelectric projects —sometimes called “water batteries" — had an average round-trip efficiency of 79%. The round-trip efficiency is a measure of the energy lost by converting electricity to another form of energy and then converting it back into electricity."... Apr 12, 2021

Link.

No. Although you have a reasonable head pressure, that is required to maintain the pressure throughout the distributions system. The static head may be significant, but the dynamic head--particularly during fire flows--is likely to be near the minimum needed. There are times when the water utility has to increase the pressure with pumps at the base of the tower. I spent a couple years as a water distribution system operator (with state licenses as needed), maintaining the electrical, pumping, etc. systems.

--JMM

In the early days, 100? years ago, some cities had separate high-pressure water systems & hydrants especially for fire fighting. The pumps were activated when called for by fire dept. personnel.

I don't know about today, but 50 years ago San Francisco had four independent water systems for fire fighting.

• The hydrants connected to the domestic water distribution system, operating at its normal pressure,
• Special high pressure lines connected to special hydrants, with their supply being two reservoirs near the top of Twin Peaks, with a pressure boosting pump station at the top of the 17th street hill--capable of supplying 800 psi (600?) water,
• Cisterns in the middle of selected intersections (you knew where they were because of a circle of bricks marking the edge of the cistern). These were a backup for when an earthquake had broken the pipes, and
• A salt water line that ran the length of Geary street from the ocean to Market street.

Yeah--they took fire safety seriously. When a station responded to an alarm you would hear additional sirens coming from other stations, as trucks were moved to the responding one so if a second alarm came in its area they could respond quickly.

--JMM

Hello,

While some may discount your concept, there are some situations where your suggestion is feasible and possible. There are available items to replace the Pressure Reducing Valves (PRVs) described by some earlier in the thread.

They are not cheap, but they scavenge the energy difference (flow x pressure drop) and respond to flow rates based on maintaining a downstream pressure. Typically they are in-line turbines with some "smarts" attached.

For a properly designed "tower" the available head would already be around the minimum level of service for the community.

We investigated one for a service line from a balance tank to treatment works. Water in balance tank either went into reservoir (25 Gig dam) at high level or direct into head of treatment plant at low level. The line to treatment plant had around 20m head with open discharge into particle screens.

Theoretical payback was around 7 years, but based on 100% availability and no unplanned events or maintenance. In our case also needed transformer to feed back to grid. Did not proceed due to perceived (financial) risk and low duty cycle. We harvested high quality water when available into the reservoir using low-tarrif power, so direct feed to plant was the non-standard option.

I was installing an automatic backwash system at a small town water plant,and the operator asked me if there was anything I could do about the continuous problems they were having in maintaining the level in the water tank.It frequently overflowed,and caused problems with the neighbor across the street from the overflow drain .They were using a leased pair of wires from the phone company,and the wires were always shorting out.The control system used a cam and mercury switch to control the pump cycle;very primitive.I installed a pressure transmitter at the water plant,not the pit,and calibrated it for the offset in level,and added a relay card to output a signal when the level reached the top,minus 6inches,and it did not overflow a single time,and provided maximum use of the storage capacity in the tank.

I added a pressure surge suppressor to eliminate oscillation by the pumps when starting or stopping.

This eliminated the transmitter in the pit,and brought the system up to date,(Which by now is obsolete due to wireless SCADA),however the system I installed worked perfectly for years with no failures.

I had a contract on the water plant and the waste treatment plant for all of their instruments,as well as all electrical maintenance and the pumps,etc.

I held an unlimited electrical license at the time,which is now retired due to health reasons.

How does PSH compare to Gravity Batteries?They are reportedly up to over 80% efficient?

https://www.bbc.com/future/article/20220511-can-gravity-batteries-solve-our-energy-storage-problems