Single Phase from a 3 Phase induction motor/generator

Are pumps and electric motors usable as turbine/generators?

Hi Robert,

Thank you so much for your generous answer. As I am not electrical, and so I am really not able to understand those diagrams and some terms, before I contact a technician here to helping me with the job, let me ask you some, in my words, willing to get your answer in the most possible simple words (as if it were for kids!):

Thanks in anvance for your teachings!.

Cheers,

Felipe

1- Are pumps (and electric motors) used as PAT (and MAG), just as they are/come from manufacturer?, or, do they need to be modified for a micro-hydro (if so, what kind of modifications)?.

1. No modifications are needed. Just force the water into where it squirted out when it was a pump. You will need to add excitation capacitors to the motor to make it generate electricity all by itself. But if it is hooked to the grid you don't need any capacitors.

2- What is the capacitors function?

2. The capacitors basically store up a bunch of electrons in a few milliseconds and dump them back into the induction generator in the next few milliseconds. So the capacitors help to bounce the current back and forth in tune with 50 or 60 Hz (cycles per second).

3- Why is it neccesary to double (2x) the pump-labeled speed (rpm) of pumps, for micro-hydro purposes?

3. There are 2 extremes with a turbine / generator. At one end we have no load and the machine spins the fastest that the water velocity will allow. At the other end we load it down so much that the speed drops to 0 RPM. The best efficiency and maximum power happens somewhere close to the middle between these two extremes. And we know where we want to be operating normally (at the midpoint) so the no load speed should be around 2X that.

4- What 'delta' connections is?

4. Delta = triangle, the three windings are connected in a triangular configuration, as opposed to star configuration. See: http://www.allaboutcircuits.com/worksheets/deltawye.html

5- What are the differences (both constructive and energy-flow-path meanning) between electric motors, and generators?.

5. Induction motors and induction generators are identical in every way. You can have an induction motor plugged in, running at 1800 RPM, consuming 746 watts (1 HP) and as soon as you start spinning that motor's shaft a little faster (with say a gasoline motor coupled to the shaft) it will start to generate electricity and feed it back to the grid and any other loads connected. This is a great and legal way to make your meter stop or even reverse.

Rob

Someone asked:


How can I  estimate roughly the maximum no load speed when impeller diamater and the net head are known.


No Load RPM= (19.1)((SQRT(64 H))/D)

Where H= Head in feet D= impeller diameter in feet



More often, you would know the full load normal operating speed of the generator to produce 60Hz from the name plate or from the number of poles. Also the head is fixed and known. So you'll want to know what the impeller diameter should be for a direct coupled setup:


Impeller Diameter in inches =(230)((SQRT(64 H))/R)


Where H = head in feet, R = No Load RPM OR 2X name plate RPM and SQRT = Square root

Net Metering, Why not Hydro?

I want to clarify the 'net metering' issue a little. I think that net metering is the most effective policy the government can implement to promote renewable energy derived from other sources besides solar & wind. If net metering were extended to all small scale (under 25KW) hydro sites, we would see a resurgence and interest in restoring thousands of small hydro sites that have been abandoned during the times of cheap oil. Many of these sites could be made productive again with lower investments because the infrastructure (dam, penstock, water supply) may still be intact. There is no valid reason to treat one renewable source any differently than another.

The advantages of a grid connection include vastly simplified control of frequency and voltage. Essentially the site runs wide open without any control and just pushes energy into the grid at the grid voltage and frequency. It is like you helping a freight train by pushing on the back of it. But you won't be able to change its speed at all, even if your efforts are doubled or stopped altogether, in other words, your energy input can fluctuate, but the train stabilizes everything just as the grid does for relatively small energy inputs.

The simplest way to get grid connected and reap these stabilizing benefits is through net metering.

Net metering is accomplished using a single-bidirectional meter, which is already in place on all grid connected homes. The newer electronic meters can be programmed to ignore the direction of the energy flow. Thus you can end up paying for the energy that you send to the grid! That way the power company keeps people from generating energy and turning their meter backward without their permission. ( Remember too, the days when Bell Telephone owned the phone lines and even the phones, and you could not connect your own! They made a ton of money charging a monthly equipment lease fee. So things will change in time with the power grid too.) The power company has to set (program) your meter to distinguish between energy coming or going.

I found this out the hard way when I first fired up our small (12KW) generator, synchronized it to the utility power line (grid), connected through a circuit breaker, opened up the butterfly valve controlling the power output and started really pushing that train. Then I sauntered out to the (electronic) meter on the pole and lo and behold the reading was increasing at a rapid rate! I could not believe that I was being charged for the power that I sent to them.

So now what can I do? Yes, I can get grid connected but only through an expensive switch which they have to approve. ( Remember Bell Telephones "approved communications interface"? ) And until I satisfy these interface switch gear requirements they won't reprogram my meter. They claim safety issues, (as Bell Telephone did up to the late '70's) But this is a red herring. If the grid goes down, (the train stops) there is no way that my 25KW is going to keep pushing that train ahead, and if it tries, any ordinary circuit breaker will disconnect me from the grid. The net metering of solar and wind energy requires little in the way of special disconnects either so why should renewable water power be any different?

So join me and lets have NET METERING FOR ALL RENEWABLE ENERGY be the law of the land! And while we are at it we should demand a favorable feed-in tariff for all renewables as well. More on that later.

Micro Hydro Engineering and Development Fee Schedule

HOW MUCH DOES IT COST AND WHEN WILL IT PAY BACK MY INVESTMENT?

Well I have to do this even though I love to show others the nuts and volts of how to DIY. I taught electronics at SUNY Orange for many years back in the '70s and still like to teach. As much as I'd like to share with everyone what I learned from building some very successful projects, I have to now charge a nominal fee to keep from having too much work and no fun. So here it is, pick the parts that you would like help with, and know you will get more than your money's worth. I'll help you out for a day for what many lawyers would charge for an hour. If you have a particularly interesting and fun site you wish to develop, send me an Email (with pictures) and let's negotiate how we can do this for less $ and more satisfaction.

STEPS TO ENERGY INDEPENDENCE a guide:

SITE SURVEY AND ENGINEERING SMALL HYDRO POWER INSTALLATIONS:

Preliminary site inspections and feasibility estimates in the local area are generally just a flat fee of $100. A stipend of $500/day is charged for the onsite data collection portion to produce the DETAILED SITE SURVEY within a 50 mi radius of Cuddebackville NY. Outside of this, travel, lodging and meal expenses are additional. The following documents are charged as listed: (you may not need all of these documents so just choose and pick what you think you need, you may request additional documentation when/if needed. If you need me to prepare local permits, you will have to send me the forms. Each side of a 2 sided form is a page.)

All the engineering documents below will be specific to your site, and the results of my survey of your site are cited and included in these documents. This custom, site specific documentation varies in length and content so page counts are estimates. Each document request must be in writing and accompanied by a check for the appropriate amount. Email works well and I accept PayPal for payments of $5000 or less. I will prepare your requested documentation and have it out to you within 30 Days of receiving your order and cleared payment. If you order multiple documents it may take me a few additional days to get them all done. For larger sites (over 50KW but less than 500KW) an additional $200 per hour design and engineering fee is charged. I can Email your documents in PDF format or print them here and mail them. Some parts of these items are interdependent and generally should be ordered in sequence or together after the DETAILED SITE SURVEY is completed.


1. DETAILED SITE SURVEY consists of:
1a. Site topography, watershed study and watershed area determination and average flow rates. (1-3 page document, includes satellite images and maps  $800)
1b. Determination of 'Q95' and 'Q50' and design head and flow rate, expected annual kWh production and valuation of the energy produced vs project cost estimates. (2-4 page doc $800)
2. Overall plan of water carrying circuits, structures (not including dams over 2' high or greater than 30' long. For design of such dams you will have to go to a civil engineering firm.), valve(s) placement and their elevations, optimum sizing and routing of penstock and discharge. Includes cost estimates. (1-2 page annotated drawings $1200)
3. Intake structures, fore-bays, self cleaning trash racks, ice and frizzle mitigation and sand, gravel, rock and log separation. Cost estimates for these items. (4-8 pages text and drawings $1500) (This can be your biggest maintenance headache, if not designed correctly for your site.)
4. Penstock pipe, materials, strength, procurement, installation methods, burying, anchoring, suspending, valves, water hammer bursting prevention, air inlet for collapse prevention, vortex air ingestion prevention and frost proofing / freeze up mitigation. (2-3 Pages w drawings $900)
5. Powerhouse design, construction and layout  considerations, water distribution plenum, discharge pit / structures and cost estimates. (2-4 pg. Plan and elevation drawings $1000)
6. Turbine type, selection and optimum sizing for your site, buy ready made or build your own. All the details plus cost estimates. (3-7 pgs $1000)
7. Generator Selection, AC or DC, 12 - 48VDC, 120VAC, 240V, or 480V 1 Phase or 3, What speed? All the answers for your site, and perfectly matched to the turbine selection, Voltage regulation and Load controllers. Including cost estimates. (2-4 pgs $1200)
8. Complete power house electrical wiring diagram and parts list with costs. An electrician with commercial experience can purchase parts and install from these plans. (2-4 pages, drawings $1500)
9. The powerhouse to home and grid connection. Transfer switches, inter-tie protection relays, Net Metering. (2-3 pgs and diagrams / drawings $1200)
10. Connecting other renewable energy sources, Solar PV , Wind etc. (3-4 pgs $900)
11. Power plant monitoring, electric energy meters, monitor your plant via the internet from anywhere, webcam monitoring. (3-5 pgs $1500)

12. Application to the Federal Energy Regulatory Commission (FERC) ($200 per page of the application as submitted + FERCs fee)
13. Application to State  Department of Environmental Protection, Conservation or equivalent ($200 Per Page + DEC / DEP fees)
14. Any other county, city, town or local permits, and/or building permit applications. ($200 PP + fees)

15. Post construction, on site, system checkout and commissioning. Expenses plus $500/day.
16. Post commissioning trouble shooting. Expenses plus $500/day.

If you are interested in retaining my services in a more open ended arrangement please see my Consulting Agreement below.


Sincere Regards and Happy Hydro
Rob


Robert J. Honders CE
Developing Technologies
Honderosa Valley Consulting and Renewables Research
Studio Building I
129 Kennel Rd.
Cuddebackville NY 12729


Honders@HVC.RR.COM

CONSULTING and RETAINER AGREEMENT

This Agreement is made effective as of ________ 1, 20__, by and between

________________________________ and Robert J. Honders Sr. CE of

Honderosa Valley Consulting and Renewables Research.

In this Agreement, the party who is contracting to receive services shall be

referred to as "Client", and the party who will be providing the services shall

be referred to as "Consultant".

Consultant has professional engineering expertise in electrical / electronics,

water resources, and developing renewable energy and hydro power

resources cost effectively and is willing to provide services to Client based

on this background. Client desires to have services provided by Consultant

for the hydropower project at ___________________________________,

herein shall be referred to as the ʻProjectʼ.

Therefore, the parties agree as follows:

1. DESCRIPTION OF SERVICES. Beginning on ________ 1, 20__, and

ending 12 months later, Consultant will provide the following services

(collectively, the "Services"): Aid in the development of the water resources

entrusted to the Client to produce electrical power and integrate this energy

with other sources and loads for the maximum benefit of the Project and

Project objectives. Consultant will provide drawings and specifications with

enough detail so that competent contractors and their purchasing agents

can acquire equipment and materials and install them to meet the

development objective. Consultant will be available to advise clientʼs 

contractors by phone during normal business hours or on site

with 24-hr. notice.

Services are billed at $300 per hour, first against the retainer.

Additional services are available such as: Design, specify, develop,

build, install and test of electronic monitoring and control systems; 

procurement and installation of rotating machinery and switch gear.

Consultant will interact with the local utility to facilitate the grid connection.

2. PERFORMANCE OF SERVICES. The manner in which the Services are

to be performed and the specific hours to be worked by Consultant shall be

determined by Consultant. Client will rely on Consultant to work as many

hours as may be reasonably necessary to fulfill Consultant's obligations

under this Agreement.

3. RETAINER/PAYMENT. Client will pay a retainer to Consultant for the

Services in the amount of $5000. This fee shall be payable in advance

upon contract signing. This retainer is not refundable. Consultant shall bill

first to the retainer. Upon depletion of retainer, Client shall pay $2000.00 for

a 3 month extension of this agreement or allow this agreement to lapse and

pay additional fees, if any, upon presentment of a billing statement

by Consultant.

4. EXPENSE REIMBURSEMENT. Consultant shall be entitled to reimburse-

ment from Client for the following "out-of-pocket" expenses: travel and

lodging expenses and travel related meals.

5. TERM/TERMINATION. This Agreement shall terminate automatically upon

completion by Consultant of the Services required by this agreement or one 

year from the effective date of this agreement.

6. RELATIONSHIP OF PARTIES. It is understood by the parties that

Consultant is an independent contractor with respect to Client, and not

an employee of Client. Client will not provide fringe benefits, including

health insurance benefits, paid vacation, or any other employee benefit,

for the benefit of Consultant.

7. EMPLOYEES. Consultant's employees, if any, who perform services for

Client under this Agreement shall also be bound by the provisions of this

Agreement.

8. NOTICES. All notices required or permitted under this Agreement shall

be in writing and shall be deemed delivered when delivered in person or

deposited in the United States mail, postage prepaid, addressed as follows:

If for Client: 

 ____________________________________    Name

 ____________________________________    Mobile

 ____________________________________    Office

 ____________________________________    Address

 ____________________________________

 ____________________________________  Email

If for Consultant: 

Robert Honders Sr CE

Honderosa Valley Consulting and Renewables Research

129 Kennel Rd

Cuddebackville NY 12729

845 754 7106

Honders@HVC.RR.com

Such address may be changed by either party by providing written notice to

the other in the manner set forth above.

9. ENTIRE AGREEMENT. This Agreement contains the entire agreement of

the parties and there are no other promises or conditions in any other

agreement whether oral or written. This Agreement supersedes any prior

written or oral agreements between the parties.

10. AMENDMENT. This Agreement may be modified or amended if the

amendment is made in writing and is signed by both parties.

11. SEVERABILITY. If any provision of this Agreement shall be held to be

invalid or unenforceable for any reason, the remaining provisions shall

continue to be valid and enforceable. If a court finds that any provision of

this Agreement is invalid or unenforceable, but that by limiting such

provision it would become valid and enforceable, then such provision

shall be deemed to be written, construed, and enforced as so limited.

12. WAIVER OF CONTRACTUAL RIGHT. The failure of either party to

enforce any provision of this Agreement shall not be construed as a

waiver or limitation of that party's right to subsequently enforce and

compel strict compliance with every provision of this Agreement.

13. APPLICABLE LAW. This Agreement shall be governed by the laws of the

State of New York.

Date:_______________

Party receiving services, Client:

By:

___________________________________________________________

Party providing services: Robert J Honders Sr. Consulting Engineer

By:

___________________________________________________________

RECEIPT

Acknowledged receipt from Client the sum of $ 5000. This payment

constitutes payment of the retainer required under Section 3 of this Agreement.

By:

___________________________________________________________

Estimating your site Hydro Power

HVC.RR
Honderosa Valley Consulting and Renewables Research

One has to remember that actual work done is force delivered times the distance that the force moved (the object) (per unit of time). So if you break a sweat pressing on an immovable wall with 100 lb pressure for several hours, you have done zero work! Because Work=Force X Distance, so 100Lb X zero distance= zero work no matter how long a time you press. But move the wall (or weight) 1 foot with your 100 Lb pressure exerted and you've done 100 ft lbs worth of work. If you do this amount of work in 1 second then you have produced about 1/5th of a horse power (HP) for that second . (550 ft lbs per second = 1 HP) One HP = about 746 watts, so you could have lit up a 100 watt light bulb for about 1.2 seconds with that work you just did. So keep lifting a 100 lb weight 1 ft every second and that is what it takes to light one light bulb!! (Approximately, there are some losses associated with the conversion of the mechanical up and down motion to electrical energy.)

In this photo you are looking at about 6000 Gal/Minute dropping through 200 feet.

Now let's relate that to hydro power.

A gallon of water weighs about 8 Lb. So if you run (drop) 13 Gal/sec (about 100 Lb) through 100 feet of height in 1 second, your total energy would be about 100 lb X 100 ft =10,000 ft lbs/ sec. divide this by 550 ft/lbs per second per HP and we get 18 HP. So at 746 W per HP our gross power in watts = 13,000W. If we sum up all the losses due to friction / heat generated etc we would probably end up with about half of that as usable electrical energy. So we could light up about 70, 100W light bulbs for as long as the water flows at 13 gal/sec or 780 gal / min. (Can you fill 3, 250 gal (standard oil) tanks in 1 minute from your water source and pipe it down hill 100 feet vertical?) Or a 5 gal pail in 1 second? Compare your stream to these kinds of estimates to get an initial approximation of potential.

If I close the valve down in my power house the pressure reads 93 PSI. This is analogous to the pressure exerted on the immovable wall above. No movement (distance = 0) no work. When I open the valve fully the water forces its way through the turbine and out the discharge (draft tube) at a rate of 750 Gal/minute. The inlet pressure drops slightly to 90 psi due to the friction the now moving water encounters against the pipe walls. These are the stats for the smaller of the two turbine / generator setups.