index page Contents List of figures List of tables List of text boxes Tips for reading and printing this manual Preface to 1995, paper version Preface to 2003, internet version Additions and corrections to 1995, paper version Download this manual: File Firefly_bm.zip, ca. 1.9 MB, unpack it and open file "ffbm_index.html" with your browser To Firefly Experiences page To Humming Bird ELC / IGC page by

Picture: The first time the prototype charger was running at the site in pilot village Cambulo, Banaue, Ifugao prov., Philippines.

1. Some drawings might be wider than your browser window and then a horizontal scrollbar will appear. Such drawings are easier to view when your browser window is as wide as possible. Maybe select a larger screen size in your computer system settings.
   A wide browser window makes that text is printed with very long lines. For reading the text only, a narrower window might be more comfortable. Or you might select a larger font size ("Text size" in "view" menu) to make text better readable.
2. For viewing pictures: Adjust `brightness' and `contrast' of your monitor such that the full color range is distinguishable ("dark grey" should look different than "black"). Text becomes easier to read when brightness is adjusted very low and contrast so high that the white background is just light enough (then "dark grey" and "black" look the same).
3. For printing the text: Try out first which font size setting (see above) gives well readable text without using too much paper.
4. If you use the "print" option of your browser, most likely drawings will not be printed at the right scale. For printing drawings to scale, you need a copy of the image file at your own computer. If you downloaded and unpacked the manual, you can just select the right image file: Its file name starts with its figure number. If you are viewing it on-line: Right-click on the drawing you want and choose option "Save picture as" to download it.
   Open the image file with an imaging or photo processing programme and print it at 150 DPI (Dots Per Inch). If it is not possible to specify a DPI in the `print' option, look for an option like `adjust image size', and then set it to 150 DPI while maintaining file size.
   Please note: Figure 5.5.a and figure 5.5b must be printed at 300 DPI to get them at the right size.
5. There is no index. For searching on keywords in the downloaded version, you might use the windows "find" tool to get a list of files where a keyword is mentioned. Below, the procedure for Windows NT is given, for other Windows versions, it might be a bit different:
   • Press "Start" button
   • Select "Find"
   • Select "Files or folders". The "find" window pops up
   • In tab-sheet "Name & Location", field "look in:", browse to the subdirectory where the un-packed *.html files of this manual are
   • In tab-sheet "Advanced", field "Of type", select the type corresponding to *.html files, e.g. "Netscape Hypertext Document"
   • In this tabsheed, field "Containing text", fill in the keyword you want to search for
   • Press "Find Now"
   • If the keyword is found in one of the files: Open this file with your browser and use its "find" function (under "Edit", or use <Ctrl>+"f" or <Alt>+"f")
   For searching in the online version, you might use the "Search" function of mr. Klunne's main micro hydropower page and open only pages in subdir ".../portegijs/firefly_bm"

This book is meant as a manual for building a firefly Micro Hydro system and setting up a firefly demonstration project. It is still a draft version. The chapters on technical issues are reasonably well worked-out by now. The introduction chapter, the ones on the firefly system in general and on local conditions have not been written with that much care. The last two chapters and many of the annexes have not been written yet. In an attempt to keep copying and postage costs within budget, the annexes that are available, are not printed in this book. These can be requested with me. Most of them deal with the considerations behind the technical design and are not relevant for people who just want to build a system. Background information that might be relevant to some readers, has been printed in boxes dispersed through the text. To keep lay-out work simple, these boxes are not printed as separate blocks of text, but only printed in italics and numbered.

For people who have got the previous draft version (of July 1994), an overview of the major changes might be interesting:

• Since then, I have built two firefly chargers and have tested one of them. My experiences in this has lead to many minor changes in charger design and in the way it could be produced. There are two important changes:
  • Nozzle design has been changed, see box 4.7 on page 4-12.
  • An `elco' capacitor has been included in the switchboard circuit to protect against voltage spikes, see box. 4.15 on page 4-62.
• The design and calibration of the charge indicator has been changed. It used to be based on a relation between open circuit voltage and state of charge of the battery obtained from SOLAR ENERGY COURSEBOOK but clearly these data were unreliable, leading to state of charge being seriously underestimated. Now it is based on a formula that is widely used in Holland and appears much more realistic.
• People who probably had as little technical experience as you, dear reader, have succesfully test-built major parts of the firefly system (see par. 1.2). So having no technical experience can not be used as an excuse any longer for claiming not to be able to build a firefly system.
• Chapter 2 and 3 have been written, I hope you will find them interesting.
• Pictures have been included.

To improve this draft version further and turn it into a useable book, I would very much appreciate reactions from readers. So please take time to write me your comments.

Another request to readers: I would like to receive data on firefly systems that have been built and installed. Aspects that are important to me are:

• Names, addresses, location on the map: Who built it, what agency is working on introducing the firefly.
• General conditions in the area (see chapter 3).
• Conditions at the site: Head, length, diameter and material of penstock pipe, was a blocking timber installed and if yes: What width.
• The user group, number of users, the way it was set up, arrangements within the user group, the way potential users look upon the firefly. Information on how the firefly was introduced in your area could be very interesting for people in other areas as well.
• Technical design: What charger design was used (of this version or of the previous draft version) and any deviations from this design. Was it built very accurately or rather rough. And on the home system: What type of battery, what type of lamps, any minor uses etc.
• Something on the economics.
• Pictures, of the area, the charger site, the charger and of users.
• Experiences until now, plans.
• Remarks, recommendations to other people who consider trying to introduce the firefly in their area.
• And last but not least: Problems, things that proved more difficult than expected, errors that were made but corrected later.
  I hope to use these information to improve the paragraphs on troubleshooting. My own ideas on what problems could crop up probably are less relevant because I know too well how the system should work. People trying to get things working might come across completely other problems and these should be included in those paragraphs.

I know that answering these questions in detail would take too much time for most readers. So please write down some basic information rather than to postpone writing until you find time to answer them all. Of course I am willing to give advice to readers who write me about problems they could not solve themselves.

Finally, I would like to thank some of the people who have contributed to my work on the firefly system. First there is engr. Simon Taylor, my successor at PRRM-Ifugao. His letters gave many hints on aspects of the design that weren't worked out properly yet and kept me in touch with what happened in the Cambulo project. Two frends gave valuable comments on the technical design: Willem Steyvers van Orsselen, a marine engineer, and Siem Broersen, an electronic engineer. Then there were the people who took the time to test-built some major parts: Catharien Ternisscha van Scheltinga and Jacobijn van Etten who built the charge indicator, and Fleur de Bruin, Gonnie van Dijk, Joost Kaptein, Eric Schulte, Maurice Simons, Saskia Stolwijk, Dominique van Unen en Josefien Versteeg, the `Gouda Group' high school students who built a charger and Theo van der Geest, their physics teacher. Fa. J. Dignum and sons let me to use their tractor and irrigation pump for testing a charger. Finally I would like to thank the people from `Casa de Pauw' for allowing me to use their workshop and computers, with special thanks to Wim van der Hoek, who kept me going with many cups of coffee, funny remarks and inspiring comments.

There are many more people who have contributed to this project, too many to mention them all here. I won't forget them...

Jan Portegijs, 9 September 1995

Copyright: Jan Portegijs, 1995.
Copying minor parts of this book with literature reference is allowed without prior authorisation. Copying major parts or the whole is allowed if the copies are meant for private use only.

A lot has happened since I finished the draft version in 1995: I went back to the Philippines to support two Philippine organisations with their efforts to introduce the firefly. This trip was paid by Dutch ODA dept. and I started my own little consultancy enterprise to qualify for that funding. My frend Siem Broersen and I developed the 'Humming bird' Electronic Load Controller / Induction Generator Controller and I wrote a building manual on that. Meanwhile, I got to know a lovely, pretty woman. We decided to try our luck and by now, we have two nice kids that need our care. Since this first ODA job, I hardly earned any money with my consultancy work so did odd jobs. Eventually, I ended up in computer work, making industrial automation software. Now I am working for a large company that produces high-tech machines for the computer chips industry.

One thing did not happen: I never wrote the missing chapters and annexes for this manual... And I don't think I ever will so quite likely, this manual will forever remain an incomplete, draft version. There is one obvious reason: I don't want to spend all of my spare time for the next year writing them. But there are some other reasons too:

1. I am less optimistic about chances that the firefly will 'break through'. From a technical point of view, the batteries are a weak point: Life span is poor when they are discharged too deeply and chances are that the case gets damaged when they are carried around so often.
   Solar energy has similar battery problems and still is much more expensive, but it is more convenient: No carrying of batteries and no troubles about sharing a charger with other users. And above all: There are funding agencies, solar cell suppliers, traders, local technicians who all support it and earn a living from it. So I guess that solar energy will win the race even in areas where suitable water sources are available. Maybe the firefly is too cheap....
2. I lack the experience about using the firefly in practice and setting up a firefly introduction project. I think these are the most interesting parts, but I can only write down some generalities and common sense about them.
   I could write the technical annexes, but I doubt whether that would make much of a difference. Part of it would be rewriting pieces of technical school books. I guess that most people who want to build a firefly system, will have enough technical knowlegde themselves or can find such information themselves. Then there are specialistic issues about details of the firefly system. These are relevant for readers who would like to adapt the firefly to their own needs. Until now, I did not receive concrete questions about these from readers so I guess there is not a great need for such information either.
3. The best way to exchange experiences between people and organisations using the firefly, nowadays is via internet.

So this is what I want to do: Build and maintain a web site on firefly projects worldwide, with reports, photo's, contact addresses, links to sites that people have made themselves, see:

http//www.microhydropower.net/mhp_group/portegijs/firefly_exp/ffexp_index.html

If you have something to show or tell, mail it to me and I will see whether it fits in.

Apart from several mistakes that were corrected and a small number of additions, this downloadable version is identical to the printed version of September 1995.

Jan Portegijs,

9 February 2003

This section is meant for people who have the paper version and would like to update it. In this internet version, these additions and corrections have of course been made already.

Insert at page 4-10 under figure 4.7:

Hacksaw sawblades can be used also.

In charger building workshops in the Philippines, people used hacksaw sawblades of which about half of the height of the blade was grinded away and probably even more at the side where it touches the outer edge of the slot. With such sawblades fitted in a normal hacksaw, they could cut the slots quite fast. However, the side disks I have seen, had slots with radiuses quite a bit larger than the design value of 14.2 mm and consequently, blades will be less strong. Also the width at the teeth is only 1.0 mm instead of 1.4 mm for jigsaw sawblades. One could try to widen the slot by cutting away material from one of the sides, but this means extra work and a less smooth result. Normally, only 1.0 mm thick blades will fit in (instead of 1.25 mm) and this makes the blades even weaker. If you are interested, see the picture "Joel Cubit cutting a side disk" in:
http://www.microhydropower.net/mhp_group/portegijs/firefly_exp/ANEX_s.html

Insert at page 4-27 between
"Both versions have been tested and worked fine up to free running speed at respectively 12 and 15 m head"
and
"With a pulley that consists of two halves..."

Anti-splashing ring for seal for pulley in one piece

With the seal type for a pulley in one piece, there was still a leakage problem: Some water comes through and gathers at the bottom of the alternator compartment. It does not pose a real danger as it comes through as a liquid and not as a fine mist of water droplets that can be sucked into the alternator: One could even drill a hole through the separation sheet at its lowest point to get rid of it.

Probably the water can come through because there is a jet of water leaking away between the runner and the nozzle. This jet hits the separation sheet just outside of the pulley and apparently, some water is forced inwards through the narrow gap between the pulley and this sheet. A solution would be to fit an anti-splashing ring of 0.5 mm galvanised iron sheet, inner diameter = 6 mm, outer diameter = 100 mm between the runner and the pulley (see fig. 4.12). This ring should prevent the water jet from splashing against the separation sheet at high speed. I haven’t tested this solution yet, please let me know whether it works.

Insert on page 4-31 below figure 4.16:

Adjustable nozzle.

Instead of fitting a suitably sized blocking timber inside the nozzle, one could also adapt nozzle design such that the flow through it, can be adjusted. This can be done by making part of the inward side hinge towards the bent side. See:
http://www.microhydropower.net/mhp_group/portegijs/firefly_exp/Tech_issues.html#adjustable_nozzle"
for a design. Such an adjustable nozzle comes in handy for:

• A demonstration charger that will be installed temporarily at sites with different heads.
• When available flow is less than the charger needs. Then one could adjust the nozzle such that it takes just a bit less flow than the canal provides so that the penstock remains full of water and the charger produces some power. Without reducing the flow, air would enter the penstock pipe, the charger would operate at a reduced head and a reduced flow and power output would be minimal.

Insert on page 4-44 at the end of par. 4.9.1:

Electronic switchboard.

There is also a design for a fully electronic switchboard, see http://www.microhydropower.net/mhp_group/portegijs/firefly_exp/Tech_issues.html#elect_switchb
It is more user-frendly and it can charge two batteries in one go. But it requires quite some electronics experience to build.

Insert on page 4-62 between:
"When the switchboard is ........... and might make short circuit etc.:
and
"Box 4.15: Voltage spikes"

Mechanical regulator might work inaccurately

Mechanical regulators might overcharge batteries batteries when used in a firefly switchboard. Once the battery becomes charged and voltage surpasses 14.7 V, the regulator does not reduce field current properly, but continues to provide full field current. Consequenty the battery is charged further and battery voltage rises to well over 15 V. Probably, this is caused by the contacts of the voltage regulator relais sticking together after having sparked a little. In a car, this problem would not occur because:

• With the motor running, the voltage regulator will vibrate. This is enough to make the contacts come loose
• The alternator can produce a much higher charging current. Then battery voltage with a fully charged battery might be well over 17 V, so the voltage regulator coil will pull the contacts loose more strongly.

The extra force needed to pull loose sticking contacts will differ all the time so this problem can not be solved by to readjusting the regulator to a lower voltage: Then on other occasions, it won't charge batteries well enough. It makes sense to check whether the spark extinghuishing diode is functioning properly. If this doesn't help: Look for an electronic regulator.

Change in table 5.2: Parts list for the charge indicator

On page 5-13, the number of red LED's should be 2 pc (instead of 3). The number of green LED's should be 5 pc (instead of 4).

Size of standard PCB board is 160 mm (instead of 150).

On page 5.16, replace "150" by "160" in the following paragraph:

• Are the dimensions still correct. The cadre around the 12 copies should measure 160 <instead of 150> x 100 mm. If on the copy, the length deviates more than 5 mm from this 160 <instead of 150> mm, the transparant is unusable because the pins of the LM 3914 chip would fit badly in the holes of <remove "on"> such a PCB.

At page 5-17 add "the diode" in paragraph:

• The square ones, for the copper wire switch, the diode and for the connections to the outside. These can best be drilled with 1 mm, so that ...

On page 5-16, add new figure

Fig. 5.5b: Alternative: Eight copies of PCB design with current shunt.

Insert on page 5-20 between:
"....the `B-' and `L-connection must be short-circuited with a piece of wire."
and:
"As stated in the parts list, the current shunt consists......"

Instead of making a current shunt from copper wire, one could also use the PCB design of fig. 5.5b with an on-board current shunt. With this PCB design, there is a copper strip between `B-' and `L-' that has such a length and width that its resistance is ca. 0.02 Ohm. Of course also thickness of this copper strip plays a role, so it can only be used with PCB material with the usual 0.035 mm copper layer. When in doubt: Check resistance afterwards by having a stable DC current going through it (e.g. from a lamp connected to a battery) and measuring voltage drop over the shunt with a digital tester on mV DC range.

Insert new text in parts list at page 5-12 in column 1 under "Current shunt, 0.02 Ohm"

(or use PCB design with on-board current shunt, see fig. 5.5b)

next (= chapter 1)

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