Installed 8/24/95 . . . updated 1/08/01
Over-shot wheel (Backhome 4/00)
Hydro System in Vermont (BackHome 9/99)
Cabin Hydro(BackHome 6/98)
Hydro System & the Environment ?
How To Figure For Hydro Electrical Generation
Hydro-electric for a Remote Ranch
Should I use water to generate
electricity?
Generating Electricity from Spring Environmently Friendly
How To Figure Power from Hydro Electrical Generation
Hydro System in Vermont
© Copyright 2000 From "Ask Mr. Solar" Column Published April 2000 Backhome Magazine
DEAR MR. SOLAR:
A small stream crosses my property and I would like to install a small water wheel to generate electricity. There isn't much vertical drop, but there is a fairly constant 200 gallons per minute even in the drought. My plan is to channel the water to an undershot wheel. I am on the grid but would like to supply some minimal lighting to remote outbuildings about 100 yards from the stream. Generators seem rather expensive. 12-volt automotive alternators are cheaper and more available. Further, automotive electrical fixtures seem resistant to dampness and are reasonable priced. Is a 12-volt alternator a good alternative to the expensive 110-volt generators? If so, what rpm range is necessary for output and optimum alternator life, and can I run a 12-volt power line that far (300 feet) without considerable power loss or special electrical equipment? Is there an inexpensive standard for low-voltage wiring to reduce the chances that somebody may accidentally splice the 12-volt line to the 110-volt line? What answers you can give are certainly appraciated! Perry A. H . . . . Jr. Windsor, PA 17366
Dear Perry
Thanks for your question--however, I must say before getting further into it that we have had very little success with undershot or overshot wheels for electrical power generation. While they might look good, there are several problems that you should be aware of before investing too deeply of your time and money.
First, if for any reason you get your alternator wet because of flooding or rising water, the electrical equipment will be ruined. Therefore, you'll have to set the alternator and wheel high enough above the creek so that in worse-case conditions (such as spring floods and heavy summer rains) the equipment will not be submerged. Second, you'll have to drive your alternator at a speed of at least 200 rpm. Using an undershot wheel (which turns at perhaps 10 or 15 rpm), that will require some form of belt or gear transmission arrangement, which becomes very inefficient when dealing with large drive ratios. Maintenance can also be a problem in the winter, when ice can unbalance and even stop the wheel.
I would strongly recommend that you re-think your idea of a using a large, traditional waterwheel (they were designed to grind grain, not make electricity) and look instead into one of the Harris Hydro micro turbines (see my interview with Don Harris in BackHome No. 28, and the article "Homegrown Hydro" in BackHome No. 13). These small-diameter Pelton wheels or "impulse turbines" as they are sometimes called are readily available and quite economical to install and use. Unlike installing an overshot or undershot wheel, where the gearing and wheel, as well as the bearings, will have to be made, the Harris Hydro setup requires only a PVC penstock or pipeline with some form of filter, and whatever it takes of your time to install the compact turbine on top of a 55-gallon drum. As basic as it sounds, these are tried and proven systems that have worked for years making electrical power without any problems. As the old saying goes, there's no reason to reinvent the wheel if there's already one that works.
You asked about running the wire some 300 feet. I would recommend that you go with a 48-volt system rather than the 12-volt configuration, as this will save you substantial line loss for that distance. According to our figures, given your 200 gallons per minute, you will get 225 watts per hour if you have a 25-foot vertical fall available. However, if you have 100-foot drop, that figure increases to 1,300 watts per hour. Since you didn't really say how much vertical drop you actually had, these numbers are only good for comparison purposes. Actual output will vary with water flow, the fall at the site, and the size PVC pipe you use for the penstock ( a 2"- to 4"-diameter pipe is adequate in most cases).
For your 48-volt system you will need #8 gauge direct burial wire if you generate 225 watt hours. If you are able to generate 1300 watt hours, then you will need a size #2 direct burial wire. If, however, you were to go with a 12-volt system, you would need #0 conductor for your 225 watt- hours. At 1,300 watt-hours the wire size is not available, so you would need to use a step-up transformer to increase your voltage and reduce your line loss.
So, to answer your last question, you will be using a very heavy wire in any case, and of course you will need fusing and boxes for this system. There should be no way that anyone should connect the 48-volt DC system to the existing household AC system because of the visible difference in the wire sizes.
There is one other possible option I'd like to mention: If your stream is flowing fast enough on its own, you can install a water generator in it. This is a 12-volt submersible generator with an attached propeller that is tethered in the flow of the stream. This spinning generator will supply up to 96 watts per hour providing you have an adequate flow rate in your stream. These are used on sailing yachts to give them the needed electrical power while underway.
Perry, I realize that the undershot wheel presents a romantic image and is very nice to look at, but I really don't believe it will be a practical solution for your needs.
Charlie welcomes your renewable-energy questions addressed to Mr. Solar, c/o BackHome magazine, P.O. Box 70, Hendersonville, NC 28793.
Hydro System in Vermont
© Copyright 1999 From "Ask Mr. Solar" Column Published September 1999 Backhome Magazine
Dear Mr. Solar:
I'm new to BackHome, and just finished reading your column in a recent issue. I am interested in converting a barn to serve as a multipurpose work and living space, which would eventually include some livestock. My plans involve using some alternative methods of power production, and I recently spoke with a friend who lives off the grid about what steps I could take to set up a stand-alone system. As I'm still in the planning stages, I am very interested in what you have to say in your renewable energy columns.
I have several questions. First, does a microhydro generator need its own inverter/charger if it's used with other forms of power such as PV? And as far as heat is concerned, why don't you ever mention wood heating or wood burning stoves? Finally, in planning for my large animals, are there any special considerations necessary, energy-wise? Pumps and cooling equipment probably use a lot of energy, but I never see them mentioned in alternative energy calculations. Would a backup generator be needed to handle these? What about cycling some of the larger equipment on a schedule so everything wouldn't be running at once? Any advice you could give would be great--thanks for your time.
Ethan M. South Burlington, Vermont
Hello Ethan
I have used and do use wood to heat part of our home at times, however I do not write about it as my column is directed to the use of forms of alternative electricity and how to generate and use it.
To answer your question about the microhydro generation you normally generate your electricity slowly and store it in batteries so that you have it available when needed for large surge usages. In other words if you generate only 1200 watts per hour then if you wanted to start a 1/2 HP motor you would not the available power to do this. Therefore you need to store your power in batteries then use an inverter to change your DC stored power into usable AC power for your motor.
Of course you can use wind, hydro and solar (PV) generating equipment to make your electricity. This power form all three sources may be stored in your batteries then used as you desire. You will need different types of controllers to regulate the power into your batteries form the different power generating sources. These controllers main job is to regulate toe power into your batteries as not to over charge them.
For your large animals I feel all they need is shelter as they have coats for the winter, however in your location it is wise to have some form of heat in your barn for them. I am afraid that I cannot properly answer this and recommend that you contact your local neighbors for their suggestions.
As far as pumps we have recently written about this and they do take a lot of power, however the use of solar for pumping is a very dependable source of pumping.
I strongly suggest that you first get an overall plan of what you plan to do by answering the following.
- - How many watts power day do I need in my new set up
- - What is the largest motor that I plan to operate and what is its power usage as well as surge.
- - How long do I need to store my power
- - How much water do I need daily
- - Am I going to have a above ground storage for water?
- - Considering hydro what fall and gallons per minute do I have available
- - Considering solar generation, where can I install panels so that they will get sun daily
Cabin Hydro
© Copyright 1995 "Ask Mr. Solar" Column Published BackHome 6/98
Hi Mr. Solar:
My husband and I have a one-room cabin approximately 16 X 20 feet on 44
acres that we use for weekends and vacation. We plan to expand the room
about the same size larger eventually to accommodate a
sleeping/eating/living area. So, we are speal\king of a total square
footage of about 650 s.f. We have a propane fireplace, a loud generator,
and outside bathroom facilities. We have a small stream running below the
cabin with an old spring but no running water inside. We have about 2
acres open and the rest wooded. We are only about 6 miles from town but
it is very secluded. We do not want electric lines marring the view.
We
want to keep this area as natural as possible, using things that will fit
with the area. We are very interested in solar energy. What number of
panels and other equipment would it take to make this a permanent home?
We are thinking of retiring here someday, permanently. I would like to be
able to use my computer, and we would like to build an indoor bathroom/
shower so we need a pressured water supply. We use gas for cooking. Can
you give a cost range per panel for the size you recommend? Also enough
info so we can budget a cost for the whole system? I also want to know if
a pond pump (fish aerator) is made to run on PV power.
Mary M . . . . . .
Roanoke, Virginia
Hello Mary -
As you probably know an alternative electrical system consists of 3 major parts which are:
There are generally 3 ways to generate your power, solar, wind, hydro and a fossil fueled generator.
In your case from what you tell us I am assuming that you have a great potential for using a micro hydro system for your power generation. Please see the interview that I did with Don Harris of Harris Hydro in the BH issue ______. This will give you all that you need to understand if it is possible for you to have a hydro system. I am assuming that your cabin is in the mountains and therefore you will have to install your water pipes and hydro generator under the frost level if you plan later to use this as a year around home. However before you install the micro hydro system you can you your "noisy generator" to generate your power.
Therefore using your generator now to generate your power and later to use your micro system to generate it you can start now with a set of batteries to store this power. What I would recommend is that you install a set of L-16 batteries, as these are very good to start with. However they will only last you up to 5 years, if you take proper care of them. Then later you can get a set of more dependable as well as less maintenance absorbent glass mat Sunlyte batteries. This is the same that are used in the stand by systems of the telephone companies and have a couple of excellent features. They will not freeze and they do not require any maintenance as well as carry a 5 year guarantee.
You should have a large battery charger of at least 50 amps per hour so that you will only have to run your generator for only an hour or so a day to give you ample power for the 24 hours. You can now get a small inverter/charger that will do this as well as give you the AC power for your house. I would recommend the Heart Freedom 1000 watt one as it has a 50 amp charger and cost well under $1000.00. You then use this inverter/charger to charge your batteries as well as give you the AC power.
I would recommend that you wire your home for AC as well as DC power. Why? I would have your water pump, refrigerator, and lights all DC power. This will mean that in the event of an inverter failure you will always have lights, refrigerator and water. Then you use the AC power to operate your kitchen toys as well as your computer and other AC items.
As far as the total system cost it will depend on how large you want to go. Your hydro, batteries and inverter/charger will cost you under $3000.00 for a small system. However you will have some cost involved in installing the hydro system such as digging the pipe line and installing the hydro below the frost line. Your Heart inverter/charger will easily run your fish aerator.
I hope this gives you an idea of what is involved with your system. You may wish to take our college course so that you will better understand your alternative electrical system and what you can expect from it. As you know we teach this college accredited solar electrical course on the internet and will be happy to send you information about it if you are interested.
Hydro System & the Environment ?
© Copyright 1995 By Charlie Collins From "Ask Mr. Solar" Column Published September 1995 Daily Spectrum
Question from Bruce M., Monterey CA
Question:
I have read your articles on the advantages of using Hydro to generate electricity,
however I would like to know how I should install one on my property which contains a
large spring. Also is there any danger in upsetting the natural balance of nature be
changing the output of the spring? I have a quantity of beavers and other microscopic
creatures living off the run off from this spring and I wonder what effect this will
have.
Mr. Solar: Bruce
- this is a very good question as many people don't care about nature and
therefore even on a small scale do upset the delicate balance.
To install a hydro system you must have water with pressure or a controlled
fall (inside a pipe) in order to generate electricity. The greater the fall
the more pressure you will generate and therefore the more electricity you
will have for your use.
I had a customer that needed about 800 watts of
electricity and he could get it by only using part of his spring which
flowed at 100 gallons a minute. They planned to install a hydro system
in Utah and would generate about 1200 watts of power at a 160 feet of fall.
However the system was installed so that they would only have 115 feet of
fall and therefore their power was reduced and they had to use all the
spring water. This change effected the environment between the spring
and hydro house. The reason for my telling you this is so that you will
not make the same mistake and destroy the home for your natural friends.
I feel that the first thing that you should do is to look at your environment
and see what will be effected by your using their water. Usually you can take
a part of the water with NO ill effects on the environment. If you have a flow
of water say 100 gallons a minute and you use 1/2 of it then you will effect
the environment, but you will not dry it up.
After you have done your review of your land, then you should design and
build your system well below the local freeze level. Plan to install a catch
basin in your spring or stream so that all large items will be removed.
Then install a pipe large enough to carry the water from your catch basin
to your hydro house. This pipe must be about twice as heavy as the maximum
pressure build up from your water fall. Then you should build a hydro house
which will hold your hydro generating system mounted on a shelf which has
an unrestricted free fall below it for the used water to exit and flow out.
Bruce, all of your system should be well protected from the cold of winter,
if you are planning to use it in the winter. We will be happy to tell you of the
type of pipe to use, size of hydro generator, and building suggestions if you will
let us know of your electrical requirements, water available and fall.
Question from Bud, Hurricane Utah
Dear Mr. Solar:
I have a lot of water flowing past my house, in the irrigation canal. Isn't there anyway that I can harness this to generate electricity?
Bud, yes there is a way, now a company back East has developed a
hydro electric submersible generator which looks like a propeller mounted on the bottom of a outboard motor.
Hydro for Irrigation Canals
© Copyright 1996 By Charlie Collins From
"Ask Mr. Solar" Column Published 1/12/96 Daily Spectrum
Actually what it is a 13" propeller mounted on a aluminum housing that encloses a 12 or 24 volt generator. You install this into your stream, which must be at least 13" deep and wide for the propeller, actually it should be probably 20" all around for the water to flow, and this means that the water must be 20" deep to give room around the propeller.
This will generate approximately 2.4 Kilowatts-hours of electricity per 24 hour period with a water flowing at thirteen feet per second. You will need at least a stream speed of three feet per second to generate electricity. You can install several of these in a stream as long as they are approximately 50 feet apart. Also if your stream is wider than you could make a funnel type arrangement so that you have more pressure flowing by the hydro electric submersible generator. The water speed and pressure directly effects the output of this equipment.
If you would like more information on this please via email
at: MrSolar@netins.net Let me know of your water flow and ditch dimension including the water depth.
How To Figure For Hydro Electrical Generation
© Copyright 1996 By Charlie Collins From "Ask Mr. Solar" Column Published 1/20/96 Daily Spectrum
Question from Jim D. > Internet
Dear Mr. Solar: I would like to know how to figure if I have enough water and fall to be able to install a hydro system for my home here in West Virginia. How do I go about figuring this out?
Jim this is a very good question and one that every one should consider if they want to install a hydro system. For a small system you figure the amount of available power in watts generated by using the following formula:
W= H X GPM X 0.18 X 0.30
W = Power in Watts
H = Head in Feet (amount of fall)
GPM = Gallons per minute
The 0.18 and the 0.30 are used to figure the efficiency.
As you see there are two important figures that you will need in order to know if you have enough power to generate electricity. They are how much gallons per minute and what is the fall. During your dry season you should figure on the amount of water that you have available per minute. To do this you construct a small dam so that all of the water will flow over a small area so that you can catch it in a 5 gallon or 50 gallon container. You should use the following formula:
GPM = 60/STF X GC
60 = 60 seconds per minute
STF = seconds to fill container
GC = gallons of container
As an example if you have a five gallon container that is filled in 10 seconds then : GPM = 60/10 X 5 and therefore you have 30 gallons per minute.
Therefore during your dry season you will have 30 gallons per minute to generate electricity with.
To figure the head in feet that you have you should get a site level. This small level ( 1"X by 6" long) is very easy to use and lets you know the fall that you have and thus you will be able to figure your power generation for a hydroelectric installation. What you do is go to your low spot on your stream to look through the level towards your water high ground and you will see a very small level inside the tube. You get this to be level and then notice where it is pointing. Then you move to that point and again point it towards your water high ground. You repeat this procedure until you are at the water high ground and multiply your findings to get your total elevation or head in feet.
Now you can use the above formula to figure the amount of watts you will generate with a hydro system.
Hydro-electric for a Remote Ranch
© Copyright 1992 By Charlie Collins From "Ask Mr. Solar" Column Published 1/12/92 Daily Spectrum
Question: Can we use running water that we have from a spring to generate electricity similar to what they do on rivers with big turbines?
Herb Fletcher, Santa Clara, Utah
Mr. Solar: Herb, there is small turbines now available for ranchers to use like the one at the D.I.Ranch.
There is an excellent double cup pelton wheel made of cast silicon bronze that many ranchers and farmers use all over the country to generate electricity. The pelton type of wheel is the most efficient for small use. Harris Hydro makes this wheel and balances each one then mounts it to an automotive type generator with a cast aluminum housing. As the water strikes the pelton wheel it spins and therefore generates electricity, just as the generator works in your truck, the main difference is that you use water to make the electricity instead of your car engine.
The amount of electricity produced depends directly on the amount of water available and the pressure or fall of the water. By fall we mean that the grater in high that the water falls through a pipe from your spring than the grater the water pressure will be. Therefore the more force will be on the pelton wheel and more electricity produced. The Harris pelton wheel will operate efficiently from 20 to 600 feet of fall and a flow of 2 to 250 gallons per minute. According to Don Harris they have currently over 5,000,000 hours of operation world wide.
Actually making electricity from running water is much more economical than making it from sun because the water runs 24 hours a day and the sun only shines 6 to 8 hours a day. The main draw back to hydro on a small system is that many times the water freezes and therefore there is no flow to generate electricity.
In addition to a pelton wheel you will need a voltage regulator and a set of batteries. You will need the voltage regulator to control the current to the batteries, as you will not want to over charge them, and "boil" them dry, thus ruining them. There are two types of voltage regulators. One takes the excess current from the batteries and sends it to another usage, such as heating water. The other one cuts off or greatly reduces the water flow at the generating source and therefore regulates the battery float level. You can regulate each type very easy and set them at whatever current level you desire.
You will need a set of batteries for two reasons, first to act as a surge capacitor and to store the power for when you wish to use it. The battery bank size would depend on the amount of power that you will generate from your pelton wheel and how much power you will want to pull out a time. Also you may want to get an invertor so that you will have alternative current (A.C.) in addition to the direct current (D.C.) that you will produce form your water wheel.
So you see the equipment is now available. You can have a simple power system set up and enjoy a pollution free home with all the advantages of city life without a monthly power bill.
Herb, if you would send us an SASE to P.O.BOX 852, La Verkin, Ut, 84745.
Please state how many gallons a minute and the fall from your spring to the sight
that you want to install your turbine, then we can give you and estimate on the
amount of power you will be able to generate.
Should I use Water to Generate Electricity?
© Copyright 1993 By Charlie Collins From "Ask Mr. Solar" Column Published 9/12/93 Daily Spectrum
Question:We have a cabin in the mountains in southern Utah and want to have some lights. We have a spring that produces three gallons per minute and drops 120 feet to our cabin. We are wondering if this small amount of water would generate electricity with a turbine. We also have a 5 kilowatt generator that we could use. As you know there is ample amount of sunlight in that area and we could use solar electric panels. What type of system would you suggest for us to install, solar, hydro or just use our generator with a battery charger? - Bill M., McAllen, Texas
Bill M., McAllen, Texas
Mr. Solar: Bill, you are lucky to have the water to your cabin with pressure created by the 120 foot drop. It is our recondition that any form of hydro electric power is better than solar panels to generate electricity. When it is cloudy and rainy solar modules are putting out very little power. In poor weather a hydro system is at its peak. With the amount of water with the pressure you should generate approximately 20 amps per day. This amount is about 50% more than you would get from a single stationary mounted solar electric panel. The 20 amps per day will accumulate to 200 amps in 10 days. You can add solar electric panels to your hydro system that will increase your power. You mentioned that you have a 5 KW generator. You should install a large battery charger to it. Then when you need more power then you merely start it and charge your batteries. We have helped install systems that only use generators at cabins. These people find that they can charge their batteries at a rate of over 60 amps per hour. Thus in only a few hours have a fully charged set of batteries.
You will need a set of storage batteries to store your power. We recommend the alkaline type. They are freeze proof and will stand more abuse than the lead acid type. A typical cabin uses approximately 75 amps per day or about 200 amps on weekends. You will also need a controller to keep your batteries from over charging. If you wire your cabin for DC power you will not need to install an inverter at this time. However if you wish to have some of the modern toys such as a micro wave, large TV, desk top computer, etc., you should install an inverter.
Bill, yes you can use your spring to your advantage to charge your batteries. Also you can use the sun as well as your generator. With this combination you will find that you will enjoy the best of both worlds. The quietness of the mountains and the electricity your city friends enjoy.
Generating Electricity from Spring Environmently Friendly
© Copyright 1995 By Charlie Collins From "Ask Mr. Solar" Column Published 2/17/95 Daily Spectrum
Question: I am building an astronomy and nature retreat in mountains of Southern Utah. This location was chosen because of the light free pollution area as well as a beautiful natural mountaintop. I will need electricity so that my guests can enjoy the stars as well as other comforts we have all become accustomed to. The cabins are located about 400' apart so that the visitors may have a nature experience in the forested area. I have a large spring and would like to use it to generate electricity, however it is located approximately a mile from the cabins. I also want to keep the environment as free as possible from added noise, smoke and smells. What do you suggest?
Bill Martin, Texas
Mr. Solar: Bill, This is a challenging situation. I have visited your beautiful remote location and make the following system design recommendations.
First I would build an electrical shed for several sets of batteries and inverters. This electrical shed should be centrally located so that the distance between each cabin is about equal. This shed should contain a separate ventilated room for the batteries apart from all switches and other electrical equipment. The electrical room you will need an inverter for each cabin which will automatically go on when power is needed at that cabin. The voltage will be increased from the 120 VAC the inverter puts out to 220 VAC for the transmission to each cabin with separate transformers installed with each inverter.
This 220 VAC transmission voltage will be steeped down to 120 VAC at each cabin. These inverters are ones that will handle input voltage of 17 VDC required to charge the Nickel Iron batteries. I would install a larger battery charger to run off your generator in the event that there is a electrical problem with your hydro due to water outage or other problems. Your spring having a fall of 120 feet will generate about 850 watts per hour or about 20,000 watts per day. This will give you ample electricity to operate your lights, Sun Frost refrigerators, as well as other electrical toys. This system is considerably less expensive than installing approximately 100 tracked solar electrical panels which would be needed to generate the same amount of power.
I would recommend you install a 4" pipe line from your spring to carry the water to a hydro generator house. We would design a couple of high voltage pelton wheel turbines.
These will produce 110 VAC three phase power. With these you install a specially designed transformer to increase the voltage to 480 VAC to be transmitted from your turbine house 5380' to your electrical shed over 3 lengths of number 12 wire. You will then install another transformer to reduce your voltage down to 12 VAC. A rectifier will be needed to change it to DC for charging your batteries.
This automatic system will be designed so you will have a minimum wire loss. When you need less power or perhaps your water volume reduces in the summer you can operate only one fourth of the hydro generation.
As your needs increase all you would need to do is open more nozzles on your hydro and thus more electricity is produced. Should you produce more electricity then the batteries will hold then the excess power will be diverted so that you will not boil your batteries dry. This system will be extremely environmentally friendly, all the pipes, electrical lines as well as the hydro equipment will be under ground to prevent freezing as well as be pleasing to the eye.
There will be a very low noise level at the hydro area and of course the water
will be returned to the environment. There is no gas smell or smoke given off
from the hydro units. Thank you for letting us design this completed system for
you and we look forward to visiting your remote retreat late next summer.
How To Figure Power from Hydro Electrical Generation
© Copyright 1996 By Charlie Collins From "Ask Mr. Solar" Column Published 2/9/96 Daily Spectrum
Question:Dear Mr. Solar: I would like to know how to figure if I have enough water and fall to be able to install a hydro system for my home here in West Virginia. How do I go about figuring this out?
Jim D. > Internet
Mr. Solar: Jim
Jim this is a very good question and one that every one should consider if they want to install a hydro system.
For a small system you figure the amount of available power in watts generated by using the following formula:
W= H X GPM X 0.18 X 0.30
W = Power in Watts
H = Head in Feet (amount of fall)
GPM = Gallons per minute
The 0.18 and the 0.30 are used to figure the efficiency.
As you see there are two important figures that you will need in order to know if you have enough power to generate electricity. They are how much gallons per minute and what is the fall. During your dry season you should figure on the amount of water that you have available per minute. To do this you construct a small dam so that all of the water will flow over a small area so that you can catch it in a 5 gallon or 50 gallon container.
You should use the following formula:
GPM = 60/STF X GC
60 = 60 seconds per minute
STF = seconds to fill container
GC = gallons of container
As an example if you have a five gallon container that is filled in 10 seconds then :
GPM = 60/10 X 5 = 30 gallons per minute
Therefore during your dry season you will have 30 gallons per minute to generate electricity with. To figure the head in feet that you have you should get a site level. This small level ( 1"X by 6" long) is very easy to use and lets you know the fall that you have and thus you will be able to figure your power generation for a hydroelectric installation. What you do is go to your low spot on your stream to look through the level towards your water high ground and you will see a very small level inside the tube. You get this to be level and then notice where it is pointing. Then you move to that point and again point it towards your water high ground. You repeat this procedure until you are at the water high ground and multiply your findings to get your total elevation or head in feet.
Now you can use the above formula to figure the amount of watts you will generate with a hydro system.