hydro electric power?

[muddstopper]

Sitting around trying to research hydropower . My wife and I are about to start building our retirement home. Shes wanting a small house, 600sqft or so. I aint buying it and am thinking 900sqft or so. Anyways, we do have a small creek on the property with about 75ft of head. I will have to bury about 1000ft of pipe. Stream flows year round and I can pull about a 4in pipe full of water off of it without degrading the stream. 75ft of head will give me about 32psi at the turbine and with the amount of flow, I should be able to run at least a 2 jet or larger turbine. The one thing I havent been able to find info on is the siphon effect of the water as it runs downhill thru the pipe. Here are my concerns. 1st, I plan on using a concrete septic tank to catch water at the head. From the concrete tank, water will be gravity fed thru 3in pipe, to reduce friction losses, to the pelton wheel at the generator. Once the water is piped to the generator, it will be tee'd to the jets. Havent decided on jet size yet. My concern is that the water just flowing thru the pipe, will it create a suction that could pull the water level down in the water holding tank. Water running into the tank should equal water running out of the tank if entrance into tank is equal to exit out of tank, but then you have approx 32psi of siphon action which makes me wonder, will I need more water entering the tank to satisfy the need of a turbine that is situated 75ft below the head. You would think that some of the hydro sites on the web would talk about this, but I havent found anything. Maybe its because its a none issue, but in my mind, it looks like it could be an issue.

 

[Egon]

Non issue. No siphon.

You have to insure that the input to the septic tank is equal to the output from the turbine. Means the turbine has to be sized to the stream flow.

 

[muddstopper]

No siphon=good for me. While I (meaning she) havent settled on a house design. I think for where we are and the available water source, hydro just makes sense. I have s a sort of plan for the hydro system to be multi use. Using a large holding tank at the head should ensure sediment and trash are minimal to reduce wear on the pelton wheel. I also intend to have another large water box where the water collects after the generator. The water temps seem to be pretty stable, around 57*F year round. I plan on placing a heat exchanger inside the lower water box and use a low pressure,/low voltage recirculating pump, in a closed loop system, to provide cooling for air conditioning in the summer. I will also be using solar collectors in the summer to heat the hot water, supplemented with wood heat for heating the water as well as the house in winter. I have built a couple of such heating/cooling systems in the past for friends with varying degrees of success. I dont plan on sharing any of my hydro generated power with the power company simply because they wont pay me for it, but I should be able to generate more power than I use. I do plan on being hooked to the grid just encase i need to service my system.

 

[pat32rf]

Around here we would need to be hooked to the grid 365 days/year and the service charges to use the grid for 2-3 days/year would be horrendous. Could you not make do with a genny for service days?

 

[muddstopper]

OH, I'll be hooked 24/7/365, but The breaker will be tripped. Pay for what ever power of theirs I need, just wont let my system back feed into theirs. Used to you could get a meter that could run backwards, and you still can if you want to pay extra for it, but several years ago they swapped all the meters out to where they dont run backwards anymore. They will take your power, if you jump thru all their hoops, but they bank the extra power for you, not pay for it. If you need their power, you get to withdraw your power from the bank, but if you produce more than you use, you never get to make a withdrawal and they keep your power. I'll have access to their power and if my system goes down, all I will have to do is flip the breaker.

 

[SPIKER]

OH, I'll be hooked 24/7/365, but The breaker will be tripped. Pay for what ever power of theirs I need, just wont let my system back feed into theirs. Used to you could get a meter that could run backwards, and you still can if you want to pay extra for it, but several years ago they swapped all the meters out to where they dont run backwards anymore. They will take your power, if you jump thru all their hoops, but they bank the extra power for you, not pay for it. If you need their power, you get to withdraw your power from the bank, but if you produce more than you use, you never get to make a withdrawal and they keep your power. I'll have access to their power and if my system goes down, all I will have to do is flip the breaker.

I thought the Feds mandated Net Metering meaning that the power company has to pay for power you put into the lines (but only at the wholesale price not retail prices.)???

M

 

[Redneck in training]

Sitting around trying to research hydropower . My wife and I are about to start building our retirement home. Shes wanting a small house, 600sqft or so. I aint buying it and am thinking 900sqft or so. Anyways, we do have a small creek on the property with about 75ft of head. I will have to bury about 1000ft of pipe. Stream flows year round and I can pull about a 4in pipe full of water off of it without degrading the stream. 75ft of head will give me about 32psi at the turbine and with the amount of flow, I should be able to run at least a 2 jet or larger turbine. The one thing I havent been able to find info on is the siphon effect of the water as it runs downhill thru the pipe. Here are my concerns. 1st, I plan on using a concrete septic tank to catch water at the head. From the concrete tank, water will be gravity fed thru 3in pipe, to reduce friction losses, to the pelton wheel at the generator. Once the water is piped to the generator, it will be tee'd to the jets. Havent decided on jet size yet. My concern is that the water just flowing thru the pipe, will it create a suction that could pull the water level down in the water holding tank. Water running into the tank should equal water running out of the tank if entrance into tank is equal to exit out of tank, but then you have approx 32psi of siphon action which makes me wonder, will I need more water entering the tank to satisfy the need of a turbine that is situated 75ft below the head. You would think that some of the hydro sites on the web would talk about this, but I haven't found anything. Maybe its because its a none issue, but in my mind, it looks like it could be an issue.

Here is one site: Power calculations for Pelton turbines
You might be better of with the energy banking arrangement. The turbine will not generate high power so in example if the electric heat or AC is used it will not cover its power requirement.

 

[muddstopper]

I have researched hydro power for some time now. Net metering only works if you if you let the power company hold all the cards. yes they will give you credit for the power you produce, at wholesale pricing, and then they charge you full price to buy your power back. I guess thats the price you pay for using there infrastructure, and I'm ok with that. But heres the rub. If you produce more power than you use, they get to keep it, giving you nothing. Around here, the Tennessee Valley Authority, (TVA), controls all the power. In order to hook alternative power sources to their grid, you have to build according to their specs. Now I can see them wanting to protect there folks not wanting you back feeding power down the system and all that, but they also want to tell you just how big of a system you can build. When building a new home with intentions of producing your own power, the TVA wants to tell you what size house to build, how you will insulate it, what kind of windows you can install, how big a power system you can build, what kind of system you can use and a host of other hoops to jump thru, or they wont let you hook your system to their grid. If you have a older house already built, and want to add a few solar panels to it, its OK, go ahead, just let us know so we can inspect it when your done. If it sounds like I have a grudge against the power company, its because i do.

While we plan on a smaller energy efficient house, I also plan a large, high energy using shop. I have equipment that will require more power than I think I can produce. My shop work would be in spurts, a few hours today, none tommorrow, maybe a little next week, that sort of thing. For this reason, the net metering makes sense as I would be banking power when I wasnt working in the shop, and then just withdraw that power when I need it. With hydro, you produce power 24/7, not just when the sun is shining. It cost a little more to use battery storage than it does to bank your power with the power company, but batteries are the route I have chosen. I dont plan on living forever and one good battery bank will probably out live me. Batteries are more reliable than the power grid. Where I will be building the house, it will be the last home on the line. If the power goes out anywhere, it will be out at my house. We lived there for years and I know how long the power can be off in that area. Using net metering, with no battery backup, might keep you in lights for a while when the grid goes down, but you would certainly be limited to the amount of power you can use. With battery storage, you are only limited to the size of the storage your batteries can provide.

 

[unimog_jason]

This might be an interesting read if you haven't seen it already:

The microhydro plant

Jason

 

[SPIKER]

looks like the TVA is a "end user negotiating one of 4 states." So you CAN negotiate with them on monthly or yearly basis to be paid for power in excess generation and said paid ).12c/KW over retail.

https://en.wikipedia.org/wiki/Solar_power_in_Tennessee

TVA: Green Power Switch Generation Partners

Mark

 

[muddstopper]

The wiki link is out dated. TVA was offering incentives for private production of green energy. The credits being given where quite generous. Solar farms where popping up everywhere, but not that many common folks where taking advantage of the offerings. What happened was there where so many large corporation taking advantage of the incentives, the TVA could no longer keep up with the cost. The program was suspended because there wasnt enough money to keep paying everybody. I will say that as of late, I have seen several new solar farms pop up. I dont know if the TVA has gotten hold of some extra money, or if this is just a delay of installing solar farms from permits that had already been issued. I actually have the application forms from the TVA for the solar setup. Funny thing is, they dont have a permitting process if you wish to use hydro. The whole thing about producing power using water is what the TVA was originally setup to do, as well as providing flood control. Since all the water in our area runs into their lakes, they dont want you messing with any streams.

 

[newbury]

This might be an interesting read if you haven't seen it already:

The microhydro plant

Jason

Everyone should read that link.
I could not imagine digging all that trench by hand to get 4KW at the end.
I'd rather run a generator.

Gabriel could have made great use of a backhoe.

 

[SPIKER]

Everyone should read that link.
I could not imagine digging all that trench by hand to get 4KW at the end.
I'd rather run a generator.

Gabriel could have made great use of a backhoe.

That guy is a hard worker for sure, heck of a Neighbor! I dont think I could have made 50 feet and I would have had to fall backwards into the hole and hope someone kicked some dirt on top!

 

[FarmWrench]

Please note that the EPA "Waters of the USA" rules are in effect. You don't own that land or water and fooling with it without permission from the EPA will prove that. Regret not writing your representative to "ditch the rule"?

Fines are hefty and remedial measures are mandatory.

(If it was a free country I'd love to build something like that. Go for six inch pipe because there will be times when "your water will come in", and the friction loss will be almost nonexistent. If you have enough flow consider a Francis style turbine.)

 

[Zerk]

If you can hook to the grid, it is a waste of time and money to do this I suspect. It is for solar and wind, especially since they are not good all day or year. Hydro may be more constant. But I have worked at real hydros, they do not produce all year to well. Spring run off is good. by August they may or may not be running. Which is why they have big dams.

 

[Zerk]

(If it was a free country I'd love to build something like that. Go for six inch pipe because there will be times when "your water will come in", and the friction loss will be almost nonexistent. If you have enough flow consider a Francis style turbine.)

As much as I am anti government regulation, I'd be concerned if my neighbor put up a dam up stream of me.

Haven't you seen those old westerns?


Hydros just slow up the water, they do no divert it to another place. I am not sure if they are building new hydros with the regulations.

 

[Raspy]

This sounds like a wonderful project. With an all year stream and 75' of drop, along with 24 hour charging, it seems like a no brainer to charge batteries and have a powerful inverter to create clean 120 volt AC power. You didn't mention how many gallons you can send to the charger, so no idea of how many amps you can generate. Keep the feed pipe large, as you mentioned, and streamline all flows to the nozzle the best you can. A tee is a severe restriction and turbulence problem. You want laminar flow through the feed pipe and a gradual nozzle taper before the Pelton wheel.

Adjust the flow to not overdraw the source and adjust the battery storage to hold all you need for heavy intermittent use. Keep in mind that usage will always rise to meet the available power, so budget yourself, if needed.

Adjusting the flow is an interesting problem. A valve at the top will cause problems with 75 feet off fall. A valve at the bottom will upset the laminar flow in the piping before the nozzle. So, set the valve about 20' up in elevation and select either a gate valve, or better yet, a globe valve.

Your design challenge, should you choose to accept it, is to balance the generator to the Pelton wheel, the nozzle(s) to the Pelton wheel and the volume of the source to the nozzles. Then to figure out how many amps you can send to the batteries.

I'd like to know how many gallons, at what elevation change, equals how many amps of 12v delivered to the batteries. That would be a very useful rule of thumb number to play with in the future.

What kind of charger will you use to control the, (I assume), DC to the batteries? Seems like a large automotive alternator with built in rectifiers is the answer. This will give you about 14.1 volts continuous. But it only has a constant drive horsepower, so it will have to be sized to the Pelton wheel/water source combination. Interesting stuff. Lots of variables. It's important to keep the generator close to the batteries as transferring lots of low volt DC over distances is inefficient.

 

[Redneck in training]

I have researched hydro power for some time now. Net metering only works if you if you let the power company hold all the cards. yes they will give you credit for the power you produce, at wholesale pricing, and then they charge you full price to buy your power back. I guess thats the price you pay for using there infrastructure, and I'm ok with that. But heres the rub. If you produce more power than you use, they get to keep it, giving you nothing. Around here, the Tennessee Valley Authority, (TVA), controls all the power. In order to hook alternative power sources to their grid, you have to build according to their specs. Now I can see them wanting to protect there folks not wanting you back feeding power down the system and all that, but they also want to tell you just how big of a system you can build. When building a new home with intentions of producing your own power, the TVA wants to tell you what size house to build, how you will insulate it, what kind of windows you can install, how big a power system you can build, what kind of system you can use and a host of other hoops to jump thru, or they wont let you hook your system to their grid. If you have a older house already built, and want to add a few solar panels to it, its OK, go ahead, just let us know so we can inspect it when your done. If it sounds like I have a grudge against the power company, its because i do.

While we plan on a smaller energy efficient house, I also plan a large, high energy using shop. I have equipment that will require more power than I think I can produce. My shop work would be in spurts, a few hours today, none tommorrow, maybe a little next week, that sort of thing. For this reason, the net metering makes sense as I would be banking power when I wasnt working in the shop, and then just withdraw that power when I need it. With hydro, you produce power 24/7, not just when the sun is shining. It cost a little more to use battery storage than it does to bank your power with the power company, but batteries are the route I have chosen. I dont plan on living forever and one good battery bank will probably out live me. Batteries are more reliable than the power grid. Where I will be building the house, it will be the last home on the line. If the power goes out anywhere, it will be out at my house. We lived there for years and I know how long the power can be off in that area. Using net metering, with no battery backup, might keep you in lights for a while when the grid goes down, but you would certainly be limited to the amount of power you can use. With battery storage, you are only limited to the size of the storage your batteries can provide.

If you go for batteries then look into NiFe made in example by Iron Edison. There also few good Chinese manufacturers of those. They are expensive in initial investment but last longer and take some abuse. You might get more power from Francis or Kaplan turbine because both of those use also suction downstream of the turbine effectively increasing the head while Pelton turbine uses only upstream head. The trade off is both Francis or Kaplan have mechanically complex guide vanes or adjustable blades. You might also find that PV might be more cost effective than hydro. Especially if you want to stay away from the utility PV is easy DIY project. Additional think to consider is permitting for hydro might be a environmental headache, the hydro requires maintenance while PV is pretty much maintenance free. PV capacity can be increased later on as needed. Another advantage of PV is that the production coincides with demand. In example you you are more likely work in the shop when the sun is shining.
Do you know how much power the hydro will generate? My guess is that you get something around 50 kWh/day. You can get the same amount from about 10kW PV costing about $15000 after tax rebate if installed DIY.
I am not trying to tell you what to do but point out that there are other options you might consider before you spend your hard earned money.

 

[Redneck in training]

Seems like a large automotive alternator with built in rectifiers is the answer. This will give you about 14.1 volts continuous. But it only has a constant drive horsepower, so it will have to be sized to the Pelton wheel/water source combination. Interesting stuff. Lots of variables. It's important to keep the generator close to the batteries as transferring lots of low volt DC over distances is inefficient.

Most car/truck alternators might be too small. If you go the automotive route look at bus or passenger railroad car generators. They are significantly larger.

 

[woodlandfarms]

For batteries, check out what Elon Musk is doing for whole house batteries.

Tesla's Elon Musk introduces 'beautiful' money-saving home battery backup system - CNET

As for your house, remember resale. 700 SF or 900 SF is a hard sell in our area, 1300 is the minimum, I know more house than you need or want but if you have kids looking toward inheritance....... Or just want some money if you have to shuffle to a retirement home.....